diff --git a/app/src/main/java/eu/darken/capod/App.kt b/app/src/main/java/eu/darken/capod/App.kt
index 92caef01..94e54202 100644
--- a/app/src/main/java/eu/darken/capod/App.kt
+++ b/app/src/main/java/eu/darken/capod/App.kt
@@ -13,6 +13,7 @@ import eu.darken.capod.common.flow.throttleLatest
 import eu.darken.capod.common.upgrade.UpgradeRepo
 import eu.darken.capod.main.ui.widget.WidgetManager
 import eu.darken.capod.monitor.core.DeviceMonitor
+
 import eu.darken.capod.monitor.core.devicesWithProfiles
 
 import kotlinx.coroutines.CoroutineScope
diff --git a/app/src/main/java/eu/darken/capod/common/compose/preview/MockPodDataProvider.kt b/app/src/main/java/eu/darken/capod/common/compose/preview/MockPodDataProvider.kt
index 1bc1a2c4..99b7c095 100644
--- a/app/src/main/java/eu/darken/capod/common/compose/preview/MockPodDataProvider.kt
+++ b/app/src/main/java/eu/darken/capod/common/compose/preview/MockPodDataProvider.kt
@@ -5,18 +5,19 @@ import eu.darken.capod.R
 import eu.darken.capod.common.bluetooth.BleScanResult
 import eu.darken.capod.common.upgrade.UpgradeRepo
 import eu.darken.capod.monitor.core.PodDevice
+import eu.darken.capod.monitor.core.cache.CachedDeviceState
+import eu.darken.capod.pods.core.apple.PodModel
 import eu.darken.capod.pods.core.apple.aap.AapPodState
 import eu.darken.capod.pods.core.apple.ble.BlePodSnapshot
 import eu.darken.capod.pods.core.apple.ble.DualBlePodSnapshot
+import eu.darken.capod.pods.core.apple.ble.SingleBlePodSnapshot
+import eu.darken.capod.pods.core.apple.ble.devices.ApplePods
 import eu.darken.capod.pods.core.apple.ble.devices.HasCase
 import eu.darken.capod.pods.core.apple.ble.devices.HasChargeDetection
 import eu.darken.capod.pods.core.apple.ble.devices.HasChargeDetectionDual
 import eu.darken.capod.pods.core.apple.ble.devices.HasDualMicrophone
 import eu.darken.capod.pods.core.apple.ble.devices.HasEarDetection
 import eu.darken.capod.pods.core.apple.ble.devices.HasEarDetectionDual
-import eu.darken.capod.pods.core.apple.PodModel
-import eu.darken.capod.pods.core.apple.ble.SingleBlePodSnapshot
-import eu.darken.capod.pods.core.apple.ble.devices.ApplePods
 import eu.darken.capod.pods.core.apple.ble.protocol.ProximityPayload
 import eu.darken.capod.pods.core.unknown.UnknownSnapshotBle
 import eu.darken.capod.profiles.core.AppleDeviceProfile
@@ -165,35 +166,73 @@ object MockPodDataProvider {
     // --- PodDevice wrappers ---
 
     fun dualPodMonitored(): PodDevice = PodDevice(
+        profileId = "preview-dual",
         ble = airPodsProFullCharge(),
         aap = null,
     )
 
     fun dualPodMonitoredMixed(): PodDevice = PodDevice(
+        profileId = "preview-dual-mixed",
         ble = airPodsProMixed(),
         aap = null,
     )
 
     fun dualPodMonitoredWithKeys(): PodDevice = PodDevice(
+        profileId = "preview-dual-keys",
         ble = airPodsProWithKeys(),
         aap = null,
     )
 
     fun dualPodMonitoredWithAap(): PodDevice = PodDevice(
+        profileId = "preview-dual-aap",
         ble = airPodsProWithKeys(),
         aap = AapPodState(connectionState = AapPodState.ConnectionState.READY),
     )
 
     fun singlePodMonitored(): PodDevice = PodDevice(
+        profileId = "preview-single",
         ble = airPodsMax(),
         aap = null,
     )
 
     fun unknownMonitored(): PodDevice = PodDevice(
+        profileId = null,
         ble = unknownDevice(),
         aap = null,
     )
 
+    /** Cached-only dual pod — device fully offline, showing last known state. */
+    fun dualPodCachedOnly(): PodDevice = PodDevice(
+        profileId = "preview-cached",
+        ble = null,
+        aap = null,
+        cached = CachedDeviceState(
+            profileId = "preview-cached",
+            model = PodModel.AIRPODS_PRO2,
+            address = "AA:BB:CC:DD:EE:FF",
+            left = CachedDeviceState.CachedBatterySlot(0.65f, MOCK_NOW.minusSeconds(3600)),
+            right = CachedDeviceState.CachedBatterySlot(0.50f, MOCK_NOW.minusSeconds(3600)),
+            case = CachedDeviceState.CachedBatterySlot(0.80f, MOCK_NOW.minusSeconds(3600)),
+            isLeftCharging = false,
+            isRightCharging = false,
+            isCaseCharging = false,
+            lastSeenAt = MOCK_NOW.minusSeconds(3600),
+        ),
+    )
+
+    /** Cached-only single pod — device fully offline, showing last known state. */
+    fun singlePodCachedOnly(): PodDevice = PodDevice(
+        profileId = "preview-cached-single",
+        ble = null,
+        aap = null,
+        cached = CachedDeviceState(
+            profileId = "preview-cached-single",
+            model = PodModel.AIRPODS_MAX,
+            headset = CachedDeviceState.CachedBatterySlot(0.40f, MOCK_NOW.minusSeconds(7200)),
+            lastSeenAt = MOCK_NOW.minusSeconds(7200),
+        ),
+    )
+
     // --- UpgradeInfo ---
 
     fun fossInfo(isPro: Boolean = false): UpgradeRepo.Info = MockUpgradeInfo(
diff --git a/app/src/main/java/eu/darken/capod/main/ui/overview/OverviewViewModel.kt b/app/src/main/java/eu/darken/capod/main/ui/overview/OverviewViewModel.kt
index dfcc07e9..ebbb0e14 100644
--- a/app/src/main/java/eu/darken/capod/main/ui/overview/OverviewViewModel.kt
+++ b/app/src/main/java/eu/darken/capod/main/ui/overview/OverviewViewModel.kt
@@ -134,8 +134,8 @@ class OverviewViewModel @Inject constructor(
         val showUnmatchedDevices: Boolean,
     ) {
         val isScanBlocked: Boolean get() = permissions.any { it.isScanBlocking }
-        val profiledDevices: List<PodDevice> get() = devices.filter { it.meta?.profile != null }
-        val unmatchedDevices: List<PodDevice> get() = devices.filter { it.meta?.profile == null }
+        val profiledDevices: List<PodDevice> get() = devices.filter { it.profileId != null }
+        val unmatchedDevices: List<PodDevice> get() = devices.filter { it.profileId == null }
     }
 
     fun onPermissionResult(@Suppress("UNUSED_PARAMETER") granted: Boolean) {
diff --git a/app/src/main/java/eu/darken/capod/main/ui/overview/cards/DualPodsCard.kt b/app/src/main/java/eu/darken/capod/main/ui/overview/cards/DualPodsCard.kt
index e7e55960..1ddfe2d1 100644
--- a/app/src/main/java/eu/darken/capod/main/ui/overview/cards/DualPodsCard.kt
+++ b/app/src/main/java/eu/darken/capod/main/ui/overview/cards/DualPodsCard.kt
@@ -31,6 +31,7 @@ import androidx.compose.runtime.Composable
 import androidx.compose.runtime.getValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
+import androidx.compose.ui.draw.alpha
 import androidx.compose.ui.graphics.StrokeCap
 import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.res.painterResource
@@ -42,6 +43,7 @@ import eu.darken.capod.common.compose.Preview2
 import eu.darken.capod.common.compose.PreviewWrapper
 import eu.darken.capod.common.compose.preview.MockPodDataProvider
 import eu.darken.capod.monitor.core.PodDevice
+import eu.darken.capod.monitor.core.cachedBatteryFormatted
 import eu.darken.capod.monitor.core.firstSeenFormatted
 import eu.darken.capod.monitor.core.getSignalQuality
 import eu.darken.capod.monitor.core.lastSeenFormatted
@@ -74,7 +76,9 @@ fun DualPodsCard(
         elevation = CardDefaults.elevatedCardElevation(defaultElevation = 2.dp),
     ) {
         Column(
-            modifier = Modifier.padding(16.dp),
+            modifier = Modifier
+                .padding(16.dp)
+                .then(if (!device.isLive) Modifier.alpha(0.7f) else Modifier),
         ) {
             // Header
             Row(
@@ -91,7 +95,7 @@ fun DualPodsCard(
 
                 Column(modifier = Modifier.weight(1f)) {
                     Text(
-                        text = device.meta?.profile?.label ?: "?",
+                        text = device.label ?: "?",
                         style = MaterialTheme.typography.titleMedium,
                         maxLines = 1,
                         overflow = TextOverflow.Ellipsis,
@@ -120,6 +124,7 @@ fun DualPodsCard(
                     signalText = device.getSignalQuality(context),
                     bleKeyState = device.bleKeyState,
                     isAapConnected = device.isAapConnected,
+                    isLive = device.isLive,
                 )
             }
 
@@ -191,6 +196,16 @@ fun DualPodsCard(
                 }
             }
 
+            // Cached battery indicator
+            if (device.isBatteryCached) {
+                Spacer(modifier = Modifier.height(4.dp))
+                Text(
+                    text = stringResource(R.string.battery_cached_label, device.cachedBatteryFormatted(now)),
+                    style = MaterialTheme.typography.bodySmall,
+                    color = MaterialTheme.colorScheme.onSurfaceVariant,
+                )
+            }
+
             // Connection state
             val stateDetection = device.ble as? HasStateDetection
             if (stateDetection != null) {
@@ -415,3 +430,9 @@ private fun DualPodsCardWithKeysPreview() = PreviewWrapper {
 private fun DualPodsCardWithAapPreview() = PreviewWrapper {
     DualPodsCard(device = MockPodDataProvider.dualPodMonitoredWithAap(), showDebug = false, now = Instant.now())
 }
+
+@Preview2
+@Composable
+private fun DualPodsCardCachedOnlyPreview() = PreviewWrapper {
+    DualPodsCard(device = MockPodDataProvider.dualPodCachedOnly(), showDebug = false, now = Instant.now())
+}
diff --git a/app/src/main/java/eu/darken/capod/main/ui/overview/cards/PodCardComponents.kt b/app/src/main/java/eu/darken/capod/main/ui/overview/cards/PodCardComponents.kt
index d37ba160..07179062 100644
--- a/app/src/main/java/eu/darken/capod/main/ui/overview/cards/PodCardComponents.kt
+++ b/app/src/main/java/eu/darken/capod/main/ui/overview/cards/PodCardComponents.kt
@@ -26,6 +26,7 @@ import androidx.compose.material.icons.twotone.KeyboardVoice
 import androidx.compose.material.icons.outlined.Key
 import androidx.compose.material.icons.twotone.Bluetooth
 import androidx.compose.material.icons.twotone.Key
+import androidx.compose.material.icons.twotone.LinkOff
 import androidx.compose.material.icons.twotone.SettingsInputAntenna
 import androidx.compose.material3.Icon
 import androidx.compose.material3.MaterialTheme
@@ -163,6 +164,7 @@ fun SignalBadge(
     signalText: String,
     bleKeyState: BleKeyState = BleKeyState.NONE,
     isAapConnected: Boolean = false,
+    isLive: Boolean = true,
     modifier: Modifier = Modifier,
 ) {
     Surface(
@@ -174,39 +176,48 @@ fun SignalBadge(
             modifier = Modifier.padding(horizontal = 6.dp, vertical = 2.dp),
             verticalAlignment = Alignment.CenterVertically,
         ) {
-            if (bleKeyState != BleKeyState.NONE) {
+            if (!isLive) {
                 Icon(
-                    imageVector = if (bleKeyState == BleKeyState.IRK_AND_ENCRYPTED) Icons.TwoTone.Key else Icons.Outlined.Key,
-                    contentDescription = stringResource(
-                        if (bleKeyState == BleKeyState.IRK_AND_ENCRYPTED) R.string.signal_badge_key_encrypted_cd
-                        else R.string.signal_badge_key_irk_cd
-                    ),
+                    imageVector = Icons.TwoTone.LinkOff,
+                    contentDescription = null,
+                    modifier = Modifier.size(12.dp),
+                    tint = MaterialTheme.colorScheme.onSurfaceVariant,
+                )
+            } else {
+                if (bleKeyState != BleKeyState.NONE) {
+                    Icon(
+                        imageVector = if (bleKeyState == BleKeyState.IRK_AND_ENCRYPTED) Icons.TwoTone.Key else Icons.Outlined.Key,
+                        contentDescription = stringResource(
+                            if (bleKeyState == BleKeyState.IRK_AND_ENCRYPTED) R.string.signal_badge_key_encrypted_cd
+                            else R.string.signal_badge_key_irk_cd
+                        ),
+                        modifier = Modifier.size(12.dp),
+                        tint = MaterialTheme.colorScheme.onSurfaceVariant,
+                    )
+                    Spacer(modifier = Modifier.width(3.dp))
+                }
+                if (isAapConnected) {
+                    Icon(
+                        imageVector = Icons.TwoTone.Bluetooth,
+                        contentDescription = stringResource(R.string.signal_badge_aap_cd),
+                        modifier = Modifier.size(12.dp),
+                        tint = MaterialTheme.colorScheme.onSurfaceVariant,
+                    )
+                    Spacer(modifier = Modifier.width(3.dp))
+                }
+                Icon(
+                    imageVector = Icons.TwoTone.SettingsInputAntenna,
+                    contentDescription = null,
                     modifier = Modifier.size(12.dp),
                     tint = MaterialTheme.colorScheme.onSurfaceVariant,
                 )
                 Spacer(modifier = Modifier.width(3.dp))
-            }
-            if (isAapConnected) {
-                Icon(
-                    imageVector = Icons.TwoTone.Bluetooth,
-                    contentDescription = stringResource(R.string.signal_badge_aap_cd),
-                    modifier = Modifier.size(12.dp),
-                    tint = MaterialTheme.colorScheme.onSurfaceVariant,
+                Text(
+                    text = signalText,
+                    style = MaterialTheme.typography.labelSmall,
+                    color = MaterialTheme.colorScheme.onSurfaceVariant,
                 )
-                Spacer(modifier = Modifier.width(3.dp))
             }
-            Icon(
-                imageVector = Icons.TwoTone.SettingsInputAntenna,
-                contentDescription = null,
-                modifier = Modifier.size(12.dp),
-                tint = MaterialTheme.colorScheme.onSurfaceVariant,
-            )
-            Spacer(modifier = Modifier.width(3.dp))
-            Text(
-                text = signalText,
-                style = MaterialTheme.typography.labelSmall,
-                color = MaterialTheme.colorScheme.onSurfaceVariant,
-            )
         }
     }
 }
diff --git a/app/src/main/java/eu/darken/capod/main/ui/overview/cards/SinglePodsCard.kt b/app/src/main/java/eu/darken/capod/main/ui/overview/cards/SinglePodsCard.kt
index cc7f3386..6cd9fddd 100644
--- a/app/src/main/java/eu/darken/capod/main/ui/overview/cards/SinglePodsCard.kt
+++ b/app/src/main/java/eu/darken/capod/main/ui/overview/cards/SinglePodsCard.kt
@@ -31,6 +31,7 @@ import androidx.compose.runtime.Composable
 import androidx.compose.runtime.getValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
+import androidx.compose.ui.draw.alpha
 import androidx.compose.ui.graphics.StrokeCap
 import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.res.painterResource
@@ -42,6 +43,7 @@ import eu.darken.capod.common.compose.Preview2
 import eu.darken.capod.common.compose.PreviewWrapper
 import eu.darken.capod.common.compose.preview.MockPodDataProvider
 import eu.darken.capod.monitor.core.PodDevice
+import eu.darken.capod.monitor.core.cachedBatteryFormatted
 import eu.darken.capod.monitor.core.firstSeenFormatted
 import eu.darken.capod.monitor.core.getSignalQuality
 import eu.darken.capod.monitor.core.lastSeenFormatted
@@ -82,7 +84,9 @@ fun SinglePodsCard(
         elevation = CardDefaults.elevatedCardElevation(defaultElevation = 2.dp),
     ) {
         Column(
-            modifier = Modifier.padding(16.dp),
+            modifier = Modifier
+                .padding(16.dp)
+                .then(if (!device.isLive) Modifier.alpha(0.7f) else Modifier),
         ) {
             // Header
             Row(
@@ -99,7 +103,7 @@ fun SinglePodsCard(
 
                 Column(modifier = Modifier.weight(1f)) {
                     Text(
-                        text = device.meta?.profile?.label ?: "?",
+                        text = device.label ?: "?",
                         style = MaterialTheme.typography.titleMedium,
                         maxLines = 1,
                         overflow = TextOverflow.Ellipsis,
@@ -117,6 +121,7 @@ fun SinglePodsCard(
                     signalText = device.getSignalQuality(context),
                     bleKeyState = device.bleKeyState,
                     isAapConnected = device.isAapConnected,
+                    isLive = device.isLive,
                 )
             }
 
@@ -214,6 +219,16 @@ fun SinglePodsCard(
                 }
             }
 
+            // Cached battery indicator
+            if (device.isBatteryCached) {
+                Spacer(modifier = Modifier.height(4.dp))
+                Text(
+                    text = stringResource(R.string.battery_cached_label, device.cachedBatteryFormatted(now)),
+                    style = MaterialTheme.typography.bodySmall,
+                    color = MaterialTheme.colorScheme.onSurfaceVariant,
+                )
+            }
+
             // ANC mode selector
             val ancMode = device.ancMode
             if (device.isAapConnected && device.hasAncControl && ancMode != null) {
@@ -245,3 +260,9 @@ private fun SinglePodsCardPreview() = PreviewWrapper {
 private fun SinglePodsCardDebugPreview() = PreviewWrapper {
     SinglePodsCard(device = MockPodDataProvider.singlePodMonitored(), showDebug = true, now = Instant.now())
 }
+
+@Preview2
+@Composable
+private fun SinglePodsCardCachedOnlyPreview() = PreviewWrapper {
+    SinglePodsCard(device = MockPodDataProvider.singlePodCachedOnly(), showDebug = false, now = Instant.now())
+}
diff --git a/app/src/main/java/eu/darken/capod/main/ui/widget/BatteryGlanceWidget.kt b/app/src/main/java/eu/darken/capod/main/ui/widget/BatteryGlanceWidget.kt
index c9f877f3..3fedd139 100644
--- a/app/src/main/java/eu/darken/capod/main/ui/widget/BatteryGlanceWidget.kt
+++ b/app/src/main/java/eu/darken/capod/main/ui/widget/BatteryGlanceWidget.kt
@@ -86,8 +86,8 @@ class BatteryGlanceWidget : GlanceAppWidget() {
 
                 val isPro = upgradeInfo?.isPro ?: initialIsPro
 
-                val liveDevice = devices.firstOrNull { it.meta?.profile?.id == profileId }
-                val device = liveDevice ?: cachedDevice?.takeIf { it.meta?.profile?.id == profileId }
+                val liveDevice = devices.firstOrNull { it.profileId == profileId }
+                val device = liveDevice ?: cachedDevice?.takeIf { it.profileId == profileId }
 
                 val profileLabel = profileId?.let { pid ->
                     profiles.firstOrNull { it.id == pid }?.label
diff --git a/app/src/main/java/eu/darken/capod/monitor/core/DeviceMonitor.kt b/app/src/main/java/eu/darken/capod/monitor/core/DeviceMonitor.kt
index 800bf90c..9b970bb8 100644
--- a/app/src/main/java/eu/darken/capod/monitor/core/DeviceMonitor.kt
+++ b/app/src/main/java/eu/darken/capod/monitor/core/DeviceMonitor.kt
@@ -1,44 +1,102 @@
 package eu.darken.capod.monitor.core
 
+import eu.darken.capod.common.coroutine.AppScope
+import eu.darken.capod.common.debug.logging.Logging.Priority.VERBOSE
 import eu.darken.capod.common.debug.logging.log
 import eu.darken.capod.common.debug.logging.logTag
+import eu.darken.capod.common.flow.replayingShare
+import eu.darken.capod.monitor.core.ble.BlePodMonitor
+import eu.darken.capod.monitor.core.cache.DeviceStateCache
+import eu.darken.capod.monitor.core.cache.toCachedState
 import eu.darken.capod.pods.core.apple.aap.AapConnectionManager
+import eu.darken.capod.profiles.core.DeviceProfilesRepo
+import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.combine
 import kotlinx.coroutines.flow.firstOrNull
+import kotlinx.coroutines.flow.onEach
 import javax.inject.Inject
 import javax.inject.Singleton
 
 /**
- * Single merge point: combines BLE scan data ([BlePodMonitor]) with AAP connection data
- * ([AapConnectionManager]) into unified [PodDevice] objects.
+ * Single merge point: combines BLE scan data ([eu.darken.capod.monitor.core.ble.BlePodMonitor]) with AAP connection data
+ * ([AapConnectionManager]) and cached device state ([eu.darken.capod.monitor.core.cache.DeviceStateCache]) into unified [PodDevice] objects.
  *
+ * Includes cached-only devices for profiles that have cached state but no live BLE data.
+ * Persists live device state to [eu.darken.capod.monitor.core.cache.DeviceStateCache] as a side effect.
  * ViewModels should observe [devices] instead of accessing BlePodMonitor directly.
  */
 @Singleton
 class DeviceMonitor @Inject constructor(
+    @AppScope private val appScope: CoroutineScope,
     private val blePodMonitor: BlePodMonitor,
     private val aapManager: AapConnectionManager,
+    private val deviceStateCache: DeviceStateCache,
+    private val profilesRepo: DeviceProfilesRepo,
 ) {
-    val devices: Flow<List<PodDevice>> = blePodMonitor.devices
-        .combine(aapManager.allStates) { pods, aapStates ->
-            pods.map { pod ->
-                // AAP connections are keyed by bonded BR/EDR address (from profile),
-                // BLE scans use rotating RPAs. Bridge via the profile's bonded address.
-                val bondedAddress = pod.meta?.profile?.address
-                PodDevice(
-                    ble = pod,
-                    aap = bondedAddress?.let { aapStates[it] },
-                )
-            }
+    val devices: Flow<List<PodDevice>> = combine(
+        blePodMonitor.devices,
+        aapManager.allStates,
+        deviceStateCache.cachedStates,
+        profilesRepo.profiles,
+    ) { pods, aapStates, cachedStates, profiles ->
+        // Live devices — BLE + AAP + cached fallback for missing fields
+        val liveDevices = pods.map { pod ->
+            val bondedAddress = pod.meta.profile?.address
+            val profile = pod.meta.profile
+            PodDevice(
+                profileId = profile?.id,
+                label = profile?.label,
+                ble = pod,
+                aap = bondedAddress?.let { aapStates[it] },
+                cached = profile?.id?.let { cachedStates[it] },
+            )
         }
 
+        // Cached-only devices — profiles with cache but no live BLE
+        val liveProfileIds = liveDevices.mapNotNull { it.profileId }.toSet()
+        val cachedOnlyDevices = profiles
+            .filter { it.id !in liveProfileIds }
+            .mapNotNull { profile ->
+                cachedStates[profile.id]?.let {
+                    PodDevice(profileId = profile.id, label = profile.label, ble = null, aap = null, cached = it)
+                }
+            }
+
+        liveDevices + cachedOnlyDevices
+    }
+        .onEach { devices -> persistLiveDevices(devices) }
+        .replayingShare(appScope)
+
+    private suspend fun persistLiveDevices(devices: List<PodDevice>) {
+        for (device in devices) {
+            val profileId = device.profileId ?: continue
+            val existing = deviceStateCache.cachedStates.value[profileId]
+            val newState = device.toCachedState(existing) ?: continue
+
+            log(TAG, VERBOSE) { "Persisting state for $profileId" }
+            deviceStateCache.save(profileId, newState)
+        }
+    }
+
     suspend fun getDeviceForProfile(profileId: String): PodDevice? {
         log(TAG) { "getDeviceForProfile(profileId=$profileId)" }
-        val bleDevice = blePodMonitor.getDeviceForProfile(profileId) ?: return null
-        val bondedAddress = bleDevice.meta?.profile?.address
-        val aapState = bondedAddress?.let { aapManager.allStates.firstOrNull()?.get(it) }
-        return PodDevice(ble = bleDevice, aap = aapState)
+
+        val liveDevice = devices.firstOrNull()?.firstOrNull { it.profileId == profileId }
+        if (liveDevice != null) {
+            log(TAG) { "Found live device for profile $profileId" }
+            return liveDevice
+        }
+
+        val cached = deviceStateCache.load(profileId)
+        if (cached != null) {
+            log(TAG) { "Found cached state for profile $profileId" }
+            val profileLabel = profilesRepo.profiles.firstOrNull()?.firstOrNull { it.id == profileId }?.label
+            return PodDevice(profileId = profileId, label = profileLabel, ble = null, aap = null, cached = cached)
+        }
+
+        log(TAG) { "No device found for profile $profileId" }
+        return null
     }
 
     companion object {
diff --git a/app/src/main/java/eu/darken/capod/monitor/core/DeviceMonitorExtensions.kt b/app/src/main/java/eu/darken/capod/monitor/core/DeviceMonitorExtensions.kt
index 0617c1d9..eed95c24 100644
--- a/app/src/main/java/eu/darken/capod/monitor/core/DeviceMonitorExtensions.kt
+++ b/app/src/main/java/eu/darken/capod/monitor/core/DeviceMonitorExtensions.kt
@@ -9,7 +9,7 @@ import java.time.Instant
 import kotlin.math.roundToInt
 
 fun DeviceMonitor.devicesWithProfiles(): Flow<List<PodDevice>> = devices
-    .map { devices -> devices.filter { it.meta?.profile != null } }
+    .map { devices -> devices.filter { it.profileId != null } }
 
 fun DeviceMonitor.primaryDevice(): Flow<PodDevice?> = devicesWithProfiles().map { it.firstOrNull() }
 
@@ -47,3 +47,27 @@ fun PodDevice.firstSeenFormatted(now: Instant): String {
         RelativeDateTimeFormatter.RelativeUnit.MINUTES
     )
 }
+
+fun PodDevice.cachedBatteryFormatted(now: Instant): String {
+    val cachedAt = cachedBatteryAt ?: return ""
+    val formatter = RelativeDateTimeFormatter.getInstance()
+    val duration = Duration.between(cachedAt, now)
+    return when {
+        duration > Duration.ofHours(1) -> formatter.format(
+            duration.toHours().toDouble(),
+            RelativeDateTimeFormatter.Direction.LAST,
+            RelativeDateTimeFormatter.RelativeUnit.HOURS
+        )
+        duration > Duration.ofMinutes(1) -> formatter.format(
+            duration.toMinutes().toDouble(),
+            RelativeDateTimeFormatter.Direction.LAST,
+            RelativeDateTimeFormatter.RelativeUnit.MINUTES
+        )
+        else -> formatter.format(
+            duration.seconds.toDouble(),
+            RelativeDateTimeFormatter.Direction.LAST,
+            RelativeDateTimeFormatter.RelativeUnit.SECONDS
+        )
+    }
+}
+
diff --git a/app/src/main/java/eu/darken/capod/monitor/core/PodDevice.kt b/app/src/main/java/eu/darken/capod/monitor/core/PodDevice.kt
index fde09bff..fadb3e59 100644
--- a/app/src/main/java/eu/darken/capod/monitor/core/PodDevice.kt
+++ b/app/src/main/java/eu/darken/capod/monitor/core/PodDevice.kt
@@ -4,20 +4,21 @@ import android.content.Context
 import androidx.compose.runtime.Stable
 import eu.darken.capod.R
 import eu.darken.capod.common.bluetooth.BluetoothAddress
+import eu.darken.capod.monitor.core.cache.CachedDeviceState
+import eu.darken.capod.pods.core.apple.PodModel
+import eu.darken.capod.pods.core.apple.aap.AapPodState
+import eu.darken.capod.pods.core.apple.aap.protocol.AapSetting
 import eu.darken.capod.pods.core.apple.ble.BlePodSnapshot
 import eu.darken.capod.pods.core.apple.ble.DualBlePodSnapshot
+import eu.darken.capod.pods.core.apple.ble.SingleBlePodSnapshot
+import eu.darken.capod.pods.core.apple.ble.devices.ApplePods
+import eu.darken.capod.pods.core.apple.ble.devices.DualApplePods
 import eu.darken.capod.pods.core.apple.ble.devices.HasCase
 import eu.darken.capod.pods.core.apple.ble.devices.HasChargeDetection
 import eu.darken.capod.pods.core.apple.ble.devices.HasChargeDetectionDual
 import eu.darken.capod.pods.core.apple.ble.devices.HasDualMicrophone
 import eu.darken.capod.pods.core.apple.ble.devices.HasEarDetection
 import eu.darken.capod.pods.core.apple.ble.devices.HasEarDetectionDual
-import eu.darken.capod.pods.core.apple.PodModel
-import eu.darken.capod.pods.core.apple.ble.SingleBlePodSnapshot
-import eu.darken.capod.pods.core.apple.ble.devices.DualApplePods
-import eu.darken.capod.pods.core.apple.ble.devices.ApplePods
-import eu.darken.capod.pods.core.apple.aap.AapPodState
-import eu.darken.capod.pods.core.apple.aap.protocol.AapSetting
 import java.time.Duration
 import java.time.Instant
 
@@ -28,17 +29,21 @@ import java.time.Instant
  */
 @Stable
 data class PodDevice(
+    val profileId: String?,
+    val label: String? = null,
     internal val ble: BlePodSnapshot?,
     internal val aap: AapPodState?,
+    internal val cached: CachedDeviceState? = null,
 ) {
-    // Identity
-    val model: PodModel get() = ble?.model ?: PodModel.UNKNOWN
+    val model: PodModel get() = ble?.model ?: cached?.model ?: PodModel.UNKNOWN
     /** Bonded BR/EDR address (from profile). Used for AAP commands. */
-    val address: BluetoothAddress? get() = ble?.meta?.profile?.address
+    val address: BluetoothAddress? get() = ble?.meta?.profile?.address ?: cached?.address
     /** BLE scan address (RPA, rotates). */
     val bleAddress: BluetoothAddress? get() = ble?.address
     val identifier: BlePodSnapshot.Id? get() = ble?.identifier
-    val meta: BlePodSnapshot.Meta? get() = ble?.meta
+
+    /** True when at least one live data source (BLE or AAP) is present. */
+    val isLive: Boolean get() = ble != null || aap != null
 
     // Capabilities from Model.Features
     val hasCase: Boolean get() = model.features.hasCase
@@ -48,7 +53,7 @@ data class PodDevice(
     val hasDualMicrophone: Boolean get() = ble is HasDualMicrophone
 
     // Signal / timing
-    val seenLastAt: Instant? get() = ble?.seenLastAt
+    val seenLastAt: Instant? get() = ble?.seenLastAt ?: cached?.lastSeenAt
     val seenFirstAt: Instant? get() = ble?.seenFirstAt
     val signalQuality: Float
         get() {
@@ -70,31 +75,54 @@ data class PodDevice(
         }
     }
 
-    // Battery — AAP preferred, BLE fallback
+    // Battery — AAP preferred, BLE fallback, then cached
     val batteryLeft: Float?
-        get() = aap?.batteryLeft ?: (ble as? DualBlePodSnapshot)?.batteryLeftPodPercent
+        get() = aap?.batteryLeft ?: (ble as? DualBlePodSnapshot)?.batteryLeftPodPercent ?: cached?.left?.percent
 
     val batteryRight: Float?
-        get() = aap?.batteryRight ?: (ble as? DualBlePodSnapshot)?.batteryRightPodPercent
+        get() = aap?.batteryRight ?: (ble as? DualBlePodSnapshot)?.batteryRightPodPercent ?: cached?.right?.percent
 
     val batteryCase: Float?
-        get() = aap?.batteryCase ?: (ble as? HasCase)?.batteryCasePercent
+        get() = aap?.batteryCase ?: (ble as? HasCase)?.batteryCasePercent ?: cached?.case?.percent
 
     val batteryHeadset: Float?
-        get() = aap?.batteryHeadset ?: (ble as? SingleBlePodSnapshot)?.batteryHeadsetPercent
+        get() = aap?.batteryHeadset ?: (ble as? SingleBlePodSnapshot)?.batteryHeadsetPercent ?: cached?.headset?.percent
 
-    // Charging — AAP preferred, BLE fallback
+    /** True when at least one displayed battery value was filled from cache (not live). */
+    val isBatteryCached: Boolean
+        get() {
+            if (cached == null) return false
+            val usedLeft = aap?.batteryLeft == null && (ble as? DualBlePodSnapshot)?.batteryLeftPodPercent == null && cached.left != null
+            val usedRight = aap?.batteryRight == null && (ble as? DualBlePodSnapshot)?.batteryRightPodPercent == null && cached.right != null
+            val usedCase = aap?.batteryCase == null && (ble as? HasCase)?.batteryCasePercent == null && cached.case != null
+            val usedHeadset = aap?.batteryHeadset == null && (ble as? SingleBlePodSnapshot)?.batteryHeadsetPercent == null && cached.headset != null
+            return usedLeft || usedRight || usedCase || usedHeadset
+        }
+
+    /** Oldest per-slot timestamp among battery values that fell through to cache. Null if all live. */
+    val cachedBatteryAt: Instant?
+        get() {
+            if (cached == null) return null
+            return listOfNotNull(
+                cached.left?.updatedAt.takeIf { aap?.batteryLeft == null && (ble as? DualBlePodSnapshot)?.batteryLeftPodPercent == null },
+                cached.right?.updatedAt.takeIf { aap?.batteryRight == null && (ble as? DualBlePodSnapshot)?.batteryRightPodPercent == null },
+                cached.case?.updatedAt.takeIf { aap?.batteryCase == null && (ble as? HasCase)?.batteryCasePercent == null },
+                cached.headset?.updatedAt.takeIf { aap?.batteryHeadset == null && (ble as? SingleBlePodSnapshot)?.batteryHeadsetPercent == null },
+            ).minOrNull()
+        }
+
+    // Charging — AAP preferred, BLE fallback, then cached
     val isLeftPodCharging: Boolean?
-        get() = aap?.isLeftCharging ?: (ble as? HasChargeDetectionDual)?.isLeftPodCharging
+        get() = aap?.isLeftCharging ?: (ble as? HasChargeDetectionDual)?.isLeftPodCharging ?: cached?.isLeftCharging
 
     val isRightPodCharging: Boolean?
-        get() = aap?.isRightCharging ?: (ble as? HasChargeDetectionDual)?.isRightPodCharging
+        get() = aap?.isRightCharging ?: (ble as? HasChargeDetectionDual)?.isRightPodCharging ?: cached?.isRightCharging
 
     val isCaseCharging: Boolean?
-        get() = aap?.isCaseCharging ?: (ble as? HasCase)?.isCaseCharging
+        get() = aap?.isCaseCharging ?: (ble as? HasCase)?.isCaseCharging ?: cached?.isCaseCharging
 
     val isHeadsetBeingCharged: Boolean?
-        get() = aap?.isHeadsetCharging ?: (ble as? HasChargeDetection)?.isHeadsetBeingCharged
+        get() = aap?.isHeadsetCharging ?: (ble as? HasChargeDetection)?.isHeadsetBeingCharged ?: cached?.isHeadsetCharging
 
     // Resolved primary pod: AAP cmd 0x08 preferred, BLE bit 5 fallback.
     private val resolvedPrimaryPod: DualBlePodSnapshot.Pod?
diff --git a/app/src/main/java/eu/darken/capod/monitor/core/PodDeviceCache.kt b/app/src/main/java/eu/darken/capod/monitor/core/PodDeviceCache.kt
deleted file mode 100644
index ca69209e..00000000
--- a/app/src/main/java/eu/darken/capod/monitor/core/PodDeviceCache.kt
+++ /dev/null
@@ -1,84 +0,0 @@
-package eu.darken.capod.monitor.core
-
-import android.content.Context
-import dagger.hilt.android.qualifiers.ApplicationContext
-import eu.darken.capod.common.bluetooth.BleScanResult
-import eu.darken.capod.common.coroutine.DispatcherProvider
-import eu.darken.capod.common.debug.logging.Logging.Priority.ERROR
-import eu.darken.capod.common.debug.logging.Logging.Priority.VERBOSE
-import eu.darken.capod.common.debug.logging.asLog
-import eu.darken.capod.common.debug.logging.log
-import eu.darken.capod.common.debug.logging.logTag
-import eu.darken.capod.common.serialization.SerializationCapod
-import eu.darken.capod.profiles.core.ProfileId
-import kotlinx.coroutines.sync.Mutex
-import kotlinx.coroutines.sync.withLock
-import kotlinx.coroutines.withContext
-import kotlinx.serialization.json.Json
-import java.io.File
-import javax.inject.Inject
-import javax.inject.Singleton
-
-@Singleton
-class PodDeviceCache @Inject constructor(
-    @ApplicationContext private val context: Context,
-    private val dispatcherProvider: DispatcherProvider,
-    @SerializationCapod private val json: Json,
-) {
-    private val cacheDir by lazy {
-        File(context.cacheDir, "device_cache").apply { mkdirs() }
-    }
-    private val lock = Mutex()
-
-    private fun ProfileId.toCacheFile(): File = File(cacheDir, "profile_${this}.json")
-
-    suspend fun load(id: ProfileId): BleScanResult? = withContext(dispatcherProvider.IO) {
-        log(TAG, VERBOSE) { "load(id=$id)" }
-        val cacheFile = id.toCacheFile()
-        lock.withLock {
-            if (!cacheFile.exists()) return@withLock null
-            try {
-                val raw = cacheFile.readText()
-                json.decodeFromString<BleScanResult>(raw)
-            } catch (e: Exception) {
-                log(TAG, ERROR) { "Failed to read profile $id device: ${e.asLog()}, deleting corrupted cache file" }
-                cacheFile.delete()
-                null
-            }
-        }
-    }
-
-    suspend fun saveAll(data: Map<ProfileId, BleScanResult>) {
-        log(TAG, VERBOSE) { "saveAll(): ${data.size} entries" }
-        lock.withLock {
-            data.forEach { (id, device) ->
-                log(TAG, VERBOSE) { "save(id=$id, device=$device)" }
-                val cacheFile = id.toCacheFile()
-                try {
-                    val encoded = json.encodeToString(BleScanResult.serializer(), device)
-                    cacheFile.writeText(encoded)
-                } catch (e: Exception) {
-                    log(TAG, ERROR) { "Failed to save profile $id device $device: ${e.asLog()}" }
-                    cacheFile.delete()
-                }
-            }
-        }
-    }
-
-    suspend fun delete(id: ProfileId) {
-        log(TAG, VERBOSE) { "delete(): profileId=$id" }
-        lock.withLock {
-            val cacheFile = id.toCacheFile()
-            try {
-                cacheFile.delete()
-            } catch (e: Exception) {
-                log(TAG, ERROR) { "Failed to delete profile for $id: ${e.asLog()}" }
-            }
-        }
-    }
-
-    companion object {
-        private val TAG = logTag("Monitor", "BlePodMonitor", "Cache")
-    }
-}
-
diff --git a/app/src/main/java/eu/darken/capod/monitor/core/PodMonitorExtensions.kt b/app/src/main/java/eu/darken/capod/monitor/core/PodMonitorExtensions.kt
deleted file mode 100644
index 4ffefc4f..00000000
--- a/app/src/main/java/eu/darken/capod/monitor/core/PodMonitorExtensions.kt
+++ /dev/null
@@ -1,10 +0,0 @@
-package eu.darken.capod.monitor.core
-
-import eu.darken.capod.pods.core.apple.ble.BlePodSnapshot
-import kotlinx.coroutines.flow.Flow
-import kotlinx.coroutines.flow.map
-
-fun BlePodMonitor.devicesWithProfiles(): Flow<List<BlePodSnapshot>> = devices
-    .map { devices -> devices.filter { it.meta.profile != null } }
-
-fun BlePodMonitor.primaryDevice(): Flow<BlePodSnapshot?> = devicesWithProfiles().map { it.firstOrNull() }
\ No newline at end of file
diff --git a/app/src/main/java/eu/darken/capod/monitor/core/PodSorter.kt b/app/src/main/java/eu/darken/capod/monitor/core/PodSorter.kt
deleted file mode 100644
index 4722c106..00000000
--- a/app/src/main/java/eu/darken/capod/monitor/core/PodSorter.kt
+++ /dev/null
@@ -1,9 +0,0 @@
-package eu.darken.capod.monitor.core
-
-import dagger.Reusable
-import javax.inject.Inject
-
-@Reusable
-class PodSorter @Inject constructor(
-
-)
\ No newline at end of file
diff --git a/app/src/main/java/eu/darken/capod/reaction/core/aap/AapKeyPersister.kt b/app/src/main/java/eu/darken/capod/monitor/core/aap/AapKeyPersister.kt
similarity index 94%
rename from app/src/main/java/eu/darken/capod/reaction/core/aap/AapKeyPersister.kt
rename to app/src/main/java/eu/darken/capod/monitor/core/aap/AapKeyPersister.kt
index a71ff2ea..ad47da86 100644
--- a/app/src/main/java/eu/darken/capod/reaction/core/aap/AapKeyPersister.kt
+++ b/app/src/main/java/eu/darken/capod/monitor/core/aap/AapKeyPersister.kt
@@ -1,4 +1,4 @@
-package eu.darken.capod.reaction.core.aap
+package eu.darken.capod.monitor.core.aap
 
 import eu.darken.capod.common.debug.logging.log
 import eu.darken.capod.common.debug.logging.logTag
@@ -47,6 +47,6 @@ class AapKeyPersister @Inject constructor(
         .setupCommonEventHandlers(TAG) { "keyPersister" }
 
     companion object {
-        private val TAG = logTag("Reaction", "AapKeyPersister")
+        private val TAG = logTag("Monitor", "AapKeyPersister")
     }
 }
diff --git a/app/src/main/java/eu/darken/capod/monitor/core/BlePodMonitor.kt b/app/src/main/java/eu/darken/capod/monitor/core/ble/BlePodMonitor.kt
similarity index 79%
rename from app/src/main/java/eu/darken/capod/monitor/core/BlePodMonitor.kt
rename to app/src/main/java/eu/darken/capod/monitor/core/ble/BlePodMonitor.kt
index 6eee861f..58532147 100644
--- a/app/src/main/java/eu/darken/capod/monitor/core/BlePodMonitor.kt
+++ b/app/src/main/java/eu/darken/capod/monitor/core/ble/BlePodMonitor.kt
@@ -1,14 +1,14 @@
-package eu.darken.capod.monitor.core
+package eu.darken.capod.monitor.core.ble
 
 import android.bluetooth.le.ScanFilter
+import eu.darken.capod.common.bluetooth.BleScanResult
 import eu.darken.capod.common.bluetooth.BleScanner
 import eu.darken.capod.common.bluetooth.BluetoothManager2
 import eu.darken.capod.common.bluetooth.ScannerMode
 import eu.darken.capod.common.bluetooth.onlyNewAndUnique
 import eu.darken.capod.common.coroutine.AppScope
 import eu.darken.capod.common.debug.DebugSettings
-import eu.darken.capod.common.debug.logging.Logging.Priority.VERBOSE
-import eu.darken.capod.common.debug.logging.Logging.Priority.WARN
+import eu.darken.capod.common.debug.logging.Logging
 import eu.darken.capod.common.debug.logging.asLog
 import eu.darken.capod.common.debug.logging.log
 import eu.darken.capod.common.debug.logging.logTag
@@ -25,10 +25,11 @@ import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.delay
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.combine
-import kotlinx.coroutines.flow.firstOrNull
 import kotlinx.coroutines.flow.flatMapLatest
+import kotlinx.coroutines.flow.flow
 import kotlinx.coroutines.flow.flowOf
 import kotlinx.coroutines.flow.map
+import kotlinx.coroutines.flow.merge
 import kotlinx.coroutines.flow.onStart
 import kotlinx.coroutines.flow.retryWhen
 import kotlinx.coroutines.sync.Mutex
@@ -46,7 +47,6 @@ class BlePodMonitor @Inject constructor(
     private val generalSettings: GeneralSettings,
     bluetoothManager: BluetoothManager2,
     private val debugSettings: DebugSettings,
-    private val podDeviceCache: PodDeviceCache,
     permissionTool: PermissionTool,
     private val profilesRepo: DeviceProfilesRepo,
 ) {
@@ -63,10 +63,16 @@ class BlePodMonitor @Inject constructor(
     }
         .flatMapLatest { isReady ->
             if (!isReady) {
-                log(TAG, WARN) { "Bluetooth is not ready" }
+                log(TAG, Logging.Priority.WARN) { "Bluetooth is not ready" }
                 flowOf(null)
             } else {
-                createBleScanner()
+                val staleEvictionTicker: Flow<Collection<BleScanResult>> = flow {
+                    while (true) {
+                        delay(STALE_EVICTION_INTERVAL.toMillis())
+                        emit(emptyList())
+                    }
+                }
+                merge(createBleScanner(), staleEvictionTicker)
             }
         }
         .map { results -> results?.mapNotNull { podFactory.createPod(it) } }
@@ -76,10 +82,13 @@ class BlePodMonitor @Inject constructor(
         }
         .retryWhen { cause, attempt ->
             if (cause is SecurityException) {
-                log(TAG, WARN) { "PodMonitor failed due to missing permission, not retrying: ${cause.asLog()}" }
+                log(
+                    TAG,
+                    Logging.Priority.WARN
+                ) { "PodMonitor failed due to missing permission, not retrying: ${cause.asLog()}" }
                 false
             } else {
-                log(TAG, WARN) { "PodMonitor failed (attempt=$attempt), will retry: ${cause.asLog()}" }
+                log(TAG, Logging.Priority.WARN) { "PodMonitor failed (attempt=$attempt), will retry: ${cause.asLog()}" }
                 delay(3000)
                 true
             }
@@ -140,7 +149,7 @@ class BlePodMonitor @Inject constructor(
         .flatMapLatest { options ->
             val filters = when {
                 options.showUnfiltered -> {
-                    log(TAG, WARN) { "Using unfiltered scan mode" }
+                    log(TAG, Logging.Priority.WARN) { "Using unfiltered scan mode" }
                     setOf(ScanFilter.Builder().build())
                 }
 
@@ -168,8 +177,8 @@ class BlePodMonitor @Inject constructor(
 
         val now = Instant.now()
         deviceCache.toList().forEach { (key, value) ->
-            if (Duration.between(value.seenLastAt, now) > Duration.ofSeconds(20)) {
-                log(TAG, VERBOSE) { "Removing stale device from cache: $value" }
+            if (Duration.between(value.seenLastAt, now) > STALE_DEVICE_TIMEOUT) {
+                log(TAG, Logging.Priority.VERBOSE) { "Removing stale device from cache: $value" }
                 deviceCache.remove(key)
             }
         }
@@ -183,35 +192,12 @@ class BlePodMonitor @Inject constructor(
             pods[it.identifier] = it
         }
 
-        newPods
-            .mapNotNull {
-                val profileId = it.device.meta.profile?.id ?: return@mapNotNull null
-                profileId to it.device.scanResult
-            }
-            .toMap()
-            .run { podDeviceCache.saveAll(this) }
         return pods
     }
 
-    suspend fun getDeviceForProfile(profileId: String): BlePodSnapshot? {
-        log(TAG) { "getDeviceForProfile(profileId=$profileId)" }
-
-        val liveDevice = devices.firstOrNull()?.firstOrNull { device ->
-            device.meta.profile?.id == profileId
-        }
-        if (liveDevice != null) {
-            log(TAG) { "Found live device for profile $profileId: $liveDevice" }
-            return liveDevice
-        }
-
-        val cachedDevice = podDeviceCache.load(profileId)?.let {
-            podFactory.createPod(it)?.device
-        }
-        log(TAG) { "Cached device for profile $profileId: $cachedDevice" }
-        return cachedDevice
-    }
-
     companion object {
         private val TAG = logTag("Monitor", "PodMonitor")
+        private val STALE_DEVICE_TIMEOUT = Duration.ofSeconds(20)
+        private val STALE_EVICTION_INTERVAL = Duration.ofSeconds(10)
     }
 }
\ No newline at end of file
diff --git a/app/src/main/java/eu/darken/capod/monitor/core/cache/CachedDeviceState.kt b/app/src/main/java/eu/darken/capod/monitor/core/cache/CachedDeviceState.kt
new file mode 100644
index 00000000..c07e99f3
--- /dev/null
+++ b/app/src/main/java/eu/darken/capod/monitor/core/cache/CachedDeviceState.kt
@@ -0,0 +1,31 @@
+package eu.darken.capod.monitor.core.cache
+
+import eu.darken.capod.common.serialization.InstantEpochMillisSerializer
+import eu.darken.capod.pods.core.apple.PodModel
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Serializable
+import java.time.Instant
+
+@Serializable
+data class CachedDeviceState(
+    @SerialName("profileId") val profileId: String,
+    @SerialName("model") val model: PodModel,
+    @SerialName("address") val address: String? = null,
+    @SerialName("left") val left: CachedBatterySlot? = null,
+    @SerialName("right") val right: CachedBatterySlot? = null,
+    @SerialName("case") val case: CachedBatterySlot? = null,
+    @SerialName("headset") val headset: CachedBatterySlot? = null,
+    @SerialName("isLeftCharging") val isLeftCharging: Boolean? = null,
+    @SerialName("isRightCharging") val isRightCharging: Boolean? = null,
+    @SerialName("isCaseCharging") val isCaseCharging: Boolean? = null,
+    @SerialName("isHeadsetCharging") val isHeadsetCharging: Boolean? = null,
+    @Serializable(with = InstantEpochMillisSerializer::class)
+    @SerialName("lastSeenAt") val lastSeenAt: Instant,
+) {
+    @Serializable
+    data class CachedBatterySlot(
+        @SerialName("percent") val percent: Float,
+        @Serializable(with = InstantEpochMillisSerializer::class)
+        @SerialName("updatedAt") val updatedAt: Instant,
+    )
+}
\ No newline at end of file
diff --git a/app/src/main/java/eu/darken/capod/monitor/core/cache/DeviceStateCache.kt b/app/src/main/java/eu/darken/capod/monitor/core/cache/DeviceStateCache.kt
new file mode 100644
index 00000000..66f6e9ec
--- /dev/null
+++ b/app/src/main/java/eu/darken/capod/monitor/core/cache/DeviceStateCache.kt
@@ -0,0 +1,120 @@
+package eu.darken.capod.monitor.core.cache
+
+import android.content.Context
+import dagger.hilt.android.qualifiers.ApplicationContext
+import eu.darken.capod.common.coroutine.AppScope
+import eu.darken.capod.common.coroutine.DispatcherProvider
+import eu.darken.capod.common.debug.logging.Logging
+import eu.darken.capod.common.debug.logging.asLog
+import eu.darken.capod.common.debug.logging.log
+import eu.darken.capod.common.debug.logging.logTag
+import eu.darken.capod.common.serialization.SerializationCapod
+import eu.darken.capod.profiles.core.ProfileId
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.launch
+import kotlinx.coroutines.sync.Mutex
+import kotlinx.coroutines.sync.withLock
+import kotlinx.coroutines.withContext
+import kotlinx.serialization.json.Json
+import java.io.File
+import javax.inject.Inject
+import javax.inject.Singleton
+
+@Singleton
+class DeviceStateCache @Inject constructor(
+    @ApplicationContext private val context: Context,
+    @AppScope private val appScope: CoroutineScope,
+    private val dispatcherProvider: DispatcherProvider,
+    @SerializationCapod private val json: Json,
+) {
+    private val cacheDir by lazy {
+        File(context.filesDir, "device_state_cache").apply { mkdirs() }
+    }
+    private val lock = Mutex()
+
+    private val _cachedStates = MutableStateFlow<Map<ProfileId, CachedDeviceState>>(emptyMap())
+    val cachedStates: StateFlow<Map<ProfileId, CachedDeviceState>> = _cachedStates
+
+    init {
+        appScope.launch { loadAll() }
+    }
+
+    private suspend fun loadAll() = withContext(dispatcherProvider.IO) {
+        lock.withLock {
+            val dir = cacheDir
+            if (!dir.exists()) return@withLock
+
+            val loaded = mutableMapOf<ProfileId, CachedDeviceState>()
+            dir.listFiles()?.filter { it.name.startsWith("profile_") && it.name.endsWith(".json") }?.forEach { file ->
+                val profileId = file.name.removePrefix("profile_").removeSuffix(".json")
+                try {
+                    val state = json.decodeFromString<CachedDeviceState>(file.readText())
+                    loaded[profileId] = state
+                } catch (e: Exception) {
+                    log(
+                        TAG,
+                        Logging.Priority.ERROR
+                    ) { "Failed to load cached state from ${file.name}: ${e.asLog()}, deleting" }
+                    file.delete()
+                }
+            }
+            log(TAG, Logging.Priority.VERBOSE) { "loadAll(): loaded ${loaded.size} entries" }
+            _cachedStates.value = loaded
+        }
+    }
+
+    private fun ProfileId.toCacheFile(): File = File(cacheDir, "profile_${this}.json")
+
+    suspend fun save(id: ProfileId, state: CachedDeviceState) = withContext(dispatcherProvider.IO) {
+        lock.withLock {
+            log(TAG, Logging.Priority.VERBOSE) { "save(id=$id)" }
+            val file = id.toCacheFile()
+            try {
+                file.writeText(json.encodeToString(CachedDeviceState.serializer(), state))
+                _cachedStates.value += (id to state)
+            } catch (e: Exception) {
+                log(TAG, Logging.Priority.ERROR) { "Failed to save state for $id: ${e.asLog()}" }
+                file.delete()
+            }
+        }
+    }
+
+    suspend fun load(id: ProfileId): CachedDeviceState? = withContext(dispatcherProvider.IO) {
+        lock.withLock {
+            val cached = _cachedStates.value[id]
+            if (cached != null) return@withContext cached
+
+            val file = id.toCacheFile()
+            if (!file.exists()) return@withContext null
+            try {
+                json.decodeFromString<CachedDeviceState>(file.readText())
+            } catch (e: Exception) {
+                log(TAG, Logging.Priority.ERROR) { "Failed to load state for $id: ${e.asLog()}, deleting" }
+                file.delete()
+                null
+            }
+        }
+    }
+
+    suspend fun delete(id: ProfileId) = withContext(dispatcherProvider.IO) {
+        lock.withLock {
+            log(TAG, Logging.Priority.VERBOSE) { "delete(id=$id)" }
+            id.toCacheFile().delete()
+            _cachedStates.value -= id
+        }
+    }
+
+    suspend fun deleteAll() = withContext(dispatcherProvider.IO) {
+        lock.withLock {
+            log(TAG, Logging.Priority.VERBOSE) { "deleteAll()" }
+            cacheDir.listFiles()?.forEach { it.delete() }
+            _cachedStates.value = emptyMap()
+        }
+    }
+
+    companion object {
+        private val TAG = logTag("Monitor", "DeviceStateCache")
+    }
+}
\ No newline at end of file
diff --git a/app/src/main/java/eu/darken/capod/monitor/core/cache/DeviceStateCacheExtensions.kt b/app/src/main/java/eu/darken/capod/monitor/core/cache/DeviceStateCacheExtensions.kt
new file mode 100644
index 00000000..617a3531
--- /dev/null
+++ b/app/src/main/java/eu/darken/capod/monitor/core/cache/DeviceStateCacheExtensions.kt
@@ -0,0 +1,63 @@
+package eu.darken.capod.monitor.core.cache
+
+import eu.darken.capod.monitor.core.PodDevice
+import eu.darken.capod.monitor.core.cache.CachedDeviceState.CachedBatterySlot
+import eu.darken.capod.pods.core.apple.ble.DualBlePodSnapshot
+import eu.darken.capod.pods.core.apple.ble.SingleBlePodSnapshot
+import eu.darken.capod.pods.core.apple.ble.devices.HasCase
+import java.time.Duration
+import java.time.Instant
+
+/**
+ * Creates a [CachedDeviceState] from this live device's raw BLE/AAP battery data.
+ * Returns null if:
+ * - The device is not live (cached-only)
+ * - The device has no profile
+ * - All live battery values are null
+ * - The state hasn't changed from [existing] (dedup)
+ */
+fun PodDevice.toCachedState(
+    existing: CachedDeviceState?,
+    now: Instant = Instant.now(),
+): CachedDeviceState? {
+    if (!isLive) return null
+    val pid = profileId ?: return null
+
+    val liveLeft = aap?.batteryLeft ?: (ble as? DualBlePodSnapshot)?.batteryLeftPodPercent
+    val liveRight = aap?.batteryRight ?: (ble as? DualBlePodSnapshot)?.batteryRightPodPercent
+    val liveCase = aap?.batteryCase ?: (ble as? HasCase)?.batteryCasePercent
+    val liveHeadset = aap?.batteryHeadset ?: (ble as? SingleBlePodSnapshot)?.batteryHeadsetPercent
+
+    if (liveLeft == null && liveRight == null && liveCase == null && liveHeadset == null) return null
+
+    val newState = CachedDeviceState(
+        profileId = pid,
+        model = model,
+        address = address,
+        left = liveLeft?.let { CachedBatterySlot(it, now) } ?: existing?.left,
+        right = liveRight?.let { CachedBatterySlot(it, now) } ?: existing?.right,
+        case = liveCase?.let { CachedBatterySlot(it, now) } ?: existing?.case,
+        headset = liveHeadset?.let { CachedBatterySlot(it, now) } ?: existing?.headset,
+        isLeftCharging = isLeftPodCharging,
+        isRightCharging = isRightPodCharging,
+        isCaseCharging = isCaseCharging,
+        isHeadsetCharging = isHeadsetBeingCharged,
+        lastSeenAt = seenLastAt ?: now,
+    )
+
+    if (existing != null && !hasStateChanged(existing, newState)) return null
+
+    return newState
+}
+
+private fun hasStateChanged(old: CachedDeviceState, new: CachedDeviceState): Boolean {
+    if (Duration.between(old.lastSeenAt, new.lastSeenAt).abs() > Duration.ofMinutes(1)) return true
+    return old.left?.percent != new.left?.percent
+        || old.right?.percent != new.right?.percent
+        || old.case?.percent != new.case?.percent
+        || old.headset?.percent != new.headset?.percent
+        || old.isLeftCharging != new.isLeftCharging
+        || old.isRightCharging != new.isRightCharging
+        || old.isCaseCharging != new.isCaseCharging
+        || old.isHeadsetCharging != new.isHeadsetCharging
+}
diff --git a/app/src/main/java/eu/darken/capod/monitor/core/worker/MonitorService.kt b/app/src/main/java/eu/darken/capod/monitor/core/worker/MonitorService.kt
index 469a4f20..32627e10 100644
--- a/app/src/main/java/eu/darken/capod/monitor/core/worker/MonitorService.kt
+++ b/app/src/main/java/eu/darken/capod/monitor/core/worker/MonitorService.kt
@@ -27,16 +27,16 @@ import eu.darken.capod.common.hasApiLevel
 import eu.darken.capod.main.core.GeneralSettings
 import eu.darken.capod.main.core.MonitorMode
 import eu.darken.capod.main.core.PermissionTool
-import eu.darken.capod.monitor.core.BlePodMonitor
 import eu.darken.capod.monitor.core.DeviceMonitor
 import eu.darken.capod.monitor.core.MonitorCoroutineScope
+import eu.darken.capod.monitor.core.aap.AapKeyPersister
+import eu.darken.capod.monitor.core.ble.BlePodMonitor
 import eu.darken.capod.monitor.core.primaryDevice
 import eu.darken.capod.monitor.ui.MonitorNotifications
+import eu.darken.capod.pods.core.apple.aap.AapConnectionManager
 import eu.darken.capod.profiles.core.DeviceProfile
 import eu.darken.capod.profiles.core.DeviceProfilesRepo
-import eu.darken.capod.pods.core.apple.aap.AapConnectionManager
 import eu.darken.capod.reaction.core.aap.AapAutoConnect
-import eu.darken.capod.reaction.core.aap.AapKeyPersister
 import eu.darken.capod.reaction.core.autoconnect.AutoConnect
 import eu.darken.capod.reaction.core.playpause.PlayPause
 import eu.darken.capod.reaction.core.popup.PopUpReaction
@@ -77,6 +77,7 @@ class MonitorService : Service() {
     @Inject lateinit var profilesRepo: DeviceProfilesRepo
     @Inject lateinit var aapAutoConnect: AapAutoConnect
     @Inject lateinit var aapKeyPersister: AapKeyPersister
+
     @Inject lateinit var aapConnectionManager: AapConnectionManager
 
     private val monitorScope = MonitorCoroutineScope()
diff --git a/app/src/main/java/eu/darken/capod/profiles/core/DeviceProfilesRepo.kt b/app/src/main/java/eu/darken/capod/profiles/core/DeviceProfilesRepo.kt
index eabd1759..438d13a2 100644
--- a/app/src/main/java/eu/darken/capod/profiles/core/DeviceProfilesRepo.kt
+++ b/app/src/main/java/eu/darken/capod/profiles/core/DeviceProfilesRepo.kt
@@ -4,11 +4,12 @@ import android.content.Context
 import dagger.hilt.android.qualifiers.ApplicationContext
 import eu.darken.capod.R
 import eu.darken.capod.common.coroutine.AppScope
+import eu.darken.capod.common.datastore.valueBlocking
 import eu.darken.capod.common.debug.logging.Logging.Priority.VERBOSE
 import eu.darken.capod.common.debug.logging.log
 import eu.darken.capod.common.debug.logging.logTag
 import eu.darken.capod.main.core.GeneralSettings
-import eu.darken.capod.monitor.core.PodDeviceCache
+import eu.darken.capod.monitor.core.cache.DeviceStateCache
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.map
@@ -17,7 +18,6 @@ import kotlinx.coroutines.sync.Mutex
 import kotlinx.coroutines.sync.withLock
 import javax.inject.Inject
 import javax.inject.Singleton
-import eu.darken.capod.common.datastore.valueBlocking
 
 @Singleton
 class DeviceProfilesRepo @Inject constructor(
@@ -25,7 +25,7 @@ class DeviceProfilesRepo @Inject constructor(
     @ApplicationContext private val context: Context,
     private val generalSettings: GeneralSettings,
     private val settings: DeviceProfilesSettings,
-    private val podDeviceCache: PodDeviceCache,
+    private val deviceStateCache: DeviceStateCache,
 ) {
 
     private val mutex = Mutex()
@@ -85,7 +85,7 @@ class DeviceProfilesRepo @Inject constructor(
         val updatedProfiles = currentContainer.profiles.filter { it.id != profileId }
         settings.profiles.valueBlocking = DeviceProfilesContainer(updatedProfiles)
         log(VERBOSE) { "Removed device profile with ID: $profileId" }
-        podDeviceCache.delete(profileId)
+        deviceStateCache.delete(profileId)
     }
 
     suspend fun reorderProfiles(profiles: List<DeviceProfile>) = mutex.withLock {
@@ -95,6 +95,7 @@ class DeviceProfilesRepo @Inject constructor(
 
     suspend fun clear() {
         settings.profiles.valueBlocking = DeviceProfilesContainer(emptyList())
+        deviceStateCache.deleteAll()
     }
 
     private fun checkAddressUniqueness(profile: DeviceProfile, existingProfiles: List<DeviceProfile>) {
diff --git a/app/src/main/java/eu/darken/capod/reaction/core/aap/AapAutoConnect.kt b/app/src/main/java/eu/darken/capod/reaction/core/aap/AapAutoConnect.kt
index 0f121301..8a7f1811 100644
--- a/app/src/main/java/eu/darken/capod/reaction/core/aap/AapAutoConnect.kt
+++ b/app/src/main/java/eu/darken/capod/reaction/core/aap/AapAutoConnect.kt
@@ -6,7 +6,7 @@ import eu.darken.capod.common.debug.logging.Logging.Priority.WARN
 import eu.darken.capod.common.debug.logging.log
 import eu.darken.capod.common.debug.logging.logTag
 import eu.darken.capod.common.flow.setupCommonEventHandlers
-import eu.darken.capod.monitor.core.BlePodMonitor
+import eu.darken.capod.monitor.core.ble.BlePodMonitor
 import eu.darken.capod.pods.core.apple.PodModel
 import eu.darken.capod.pods.core.apple.aap.AapConnectionManager
 import eu.darken.capod.pods.core.apple.aap.AapPodState
@@ -24,9 +24,9 @@ import kotlinx.coroutines.flow.merge
 import kotlinx.coroutines.flow.onEach
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.withTimeout
-import kotlin.time.Duration.Companion.seconds
 import javax.inject.Inject
 import javax.inject.Singleton
+import kotlin.time.Duration.Companion.seconds
 
 @Singleton
 class AapAutoConnect @Inject constructor(
diff --git a/app/src/main/java/eu/darken/capod/reaction/core/autoconnect/AutoConnect.kt b/app/src/main/java/eu/darken/capod/reaction/core/autoconnect/AutoConnect.kt
index f952bd4e..4400c4f7 100644
--- a/app/src/main/java/eu/darken/capod/reaction/core/autoconnect/AutoConnect.kt
+++ b/app/src/main/java/eu/darken/capod/reaction/core/autoconnect/AutoConnect.kt
@@ -49,7 +49,7 @@ class AutoConnect @Inject constructor(
         .map { (connectedDevices, mainDevice) ->
             log(TAG, VERBOSE) { "mainPodDevice is $mainDevice" }
 
-            val mainDeviceAddr = mainDevice.meta?.profile?.address
+            val mainDeviceAddr = mainDevice.address
             if (mainDeviceAddr.isNullOrEmpty()) {
                 log(TAG, WARN) { "mainDeviceAddress is null" }
                 return@map
diff --git a/app/src/main/java/eu/darken/capod/reaction/core/popup/PopUpReaction.kt b/app/src/main/java/eu/darken/capod/reaction/core/popup/PopUpReaction.kt
index a79a381c..41dbb701 100644
--- a/app/src/main/java/eu/darken/capod/reaction/core/popup/PopUpReaction.kt
+++ b/app/src/main/java/eu/darken/capod/reaction/core/popup/PopUpReaction.kt
@@ -53,7 +53,7 @@ class PopUpReaction @Inject constructor(
             log(TAG, VERBOSE) { "previous-id=${previous?.identifier}, current-id=${current.identifier}" }
 
             val isSameDeviceOrProfile = previous?.identifier == current.identifier ||
-                    (previous?.meta?.profile?.id != null && previous.meta?.profile?.id == current.meta?.profile?.id)
+                    (previous?.profileId != null && previous.profileId == current.profileId)
             val isSameDeviceWithCaseNowOpen = isSameDeviceOrProfile && previous?.caseLidState != current.caseLidState
             val isNewDeviceWithJustOpenedCase = !isSameDeviceOrProfile && previous?.caseLidState != current.caseLidState
 
@@ -66,7 +66,7 @@ class PopUpReaction @Inject constructor(
         }
 
     private fun throttleCasePopUps(current: PodDevice): Event? {
-        val cooldownKey = current.meta?.profile?.id ?: current.identifier.toString()
+        val cooldownKey = current.profileId ?: current.identifier.toString()
         val now = Instant.now()
         val lastShown = caseCoolDowns[cooldownKey]
 
@@ -110,7 +110,7 @@ class PopUpReaction @Inject constructor(
                 deviceMonitor.primaryDevice().distinctUntilChangedBy { it?.rawDataHex },
             ) { devices, broadcast ->
                 log(TAG) { "$broadcast $devices " }
-                val primaryAddr = broadcast?.meta?.profile?.address
+                val primaryAddr = broadcast?.address
                 val direct = devices.singleOrNull { it.address == primaryAddr }.also {
                     log(TAG, VERBOSE) { "Connected main device is $it" }
                 }
diff --git a/app/src/main/java/eu/darken/capod/troubleshooter/ui/TroubleShooterViewModel.kt b/app/src/main/java/eu/darken/capod/troubleshooter/ui/TroubleShooterViewModel.kt
index c778a78b..09b0600a 100644
--- a/app/src/main/java/eu/darken/capod/troubleshooter/ui/TroubleShooterViewModel.kt
+++ b/app/src/main/java/eu/darken/capod/troubleshooter/ui/TroubleShooterViewModel.kt
@@ -13,8 +13,8 @@ import eu.darken.capod.common.debug.logging.log
 import eu.darken.capod.common.debug.logging.logTag
 import eu.darken.capod.common.uix.ViewModel4
 import eu.darken.capod.main.core.GeneralSettings
-import eu.darken.capod.monitor.core.BlePodMonitor
 import eu.darken.capod.monitor.core.DeviceMonitor
+import eu.darken.capod.monitor.core.ble.BlePodMonitor
 import eu.darken.capod.monitor.core.primaryDevice
 import eu.darken.capod.pods.core.apple.ble.BlePodSnapshot
 import eu.darken.capod.pods.core.unknown.UnknownSnapshotBle
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index e25b957b..f34cf13c 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -273,6 +273,7 @@
 
     <string name="last_seen_x">Last seen: %s</string>
     <string name="first_seen_x">First seen: %s</string>
+    <string name="battery_cached_label">Last known \u00B7 %s</string>
     <string name="permission_post_notifications_label">Show notifications</string>
     <string name="permission_post_notifications_description">"Allow CAPod to show notifications about your AirPods, e.g. their current status while connected."</string>
 
diff --git a/app/src/test/java/eu/darken/capod/main/ui/overview/OverviewViewModelTest.kt b/app/src/test/java/eu/darken/capod/main/ui/overview/OverviewViewModelTest.kt
index 248baa46..e6edf51b 100644
--- a/app/src/test/java/eu/darken/capod/main/ui/overview/OverviewViewModelTest.kt
+++ b/app/src/test/java/eu/darken/capod/main/ui/overview/OverviewViewModelTest.kt
@@ -155,7 +155,7 @@ class OverviewViewModelTest : BaseTest() {
 
         @Test
         fun `devices passed through when permissions granted`() = runTest(testDispatcher) {
-            val device = PodDevice(ble = mockk(relaxed = true), aap = null)
+            val device = PodDevice(profileId = null, ble = mockk(relaxed = true), aap = null)
             devicesFlow.value = listOf(device)
 
             val vm = createViewModel()
@@ -166,18 +166,14 @@ class OverviewViewModelTest : BaseTest() {
 
         @Test
         fun `profiledDevices returns only devices with non-null profile`() {
-            val withProfile = object : BlePodSnapshot.Meta {
-                override val profile: DeviceProfile = AppleDeviceProfile(label = "Test")
-            }
-            val withoutProfile = object : BlePodSnapshot.Meta {
-                override val profile: DeviceProfile? = null
-            }
             val profiled = PodDevice(
-                ble = mockk(relaxed = true) { every { meta } returns withProfile },
+                profileId = "test-id",
+                ble = mockk(relaxed = true),
                 aap = null,
             )
             val unmatched = PodDevice(
-                ble = mockk(relaxed = true) { every { meta } returns withoutProfile },
+                profileId = null,
+                ble = mockk(relaxed = true),
                 aap = null,
             )
 
@@ -197,18 +193,14 @@ class OverviewViewModelTest : BaseTest() {
 
         @Test
         fun `unmatchedDevices returns only devices with null profile`() {
-            val withProfile = object : BlePodSnapshot.Meta {
-                override val profile: DeviceProfile = AppleDeviceProfile(label = "Test")
-            }
-            val withoutProfile = object : BlePodSnapshot.Meta {
-                override val profile: DeviceProfile? = null
-            }
             val profiled = PodDevice(
-                ble = mockk(relaxed = true) { every { meta } returns withProfile },
+                profileId = "test-id",
+                ble = mockk(relaxed = true),
                 aap = null,
             )
             val unmatched = PodDevice(
-                ble = mockk(relaxed = true) { every { meta } returns withoutProfile },
+                profileId = null,
+                ble = mockk(relaxed = true),
                 aap = null,
             )
 
diff --git a/app/src/test/java/eu/darken/capod/monitor/core/PodDeviceCacheTest.kt b/app/src/test/java/eu/darken/capod/monitor/core/PodDeviceCacheTest.kt
new file mode 100644
index 00000000..53ff609e
--- /dev/null
+++ b/app/src/test/java/eu/darken/capod/monitor/core/PodDeviceCacheTest.kt
@@ -0,0 +1,202 @@
+package eu.darken.capod.monitor.core
+
+import eu.darken.capod.monitor.core.cache.CachedDeviceState
+import eu.darken.capod.pods.core.apple.PodModel
+import eu.darken.capod.pods.core.apple.aap.AapPodState
+import eu.darken.capod.pods.core.apple.ble.devices.DualApplePods
+import io.kotest.matchers.nulls.shouldBeNull
+import io.kotest.matchers.nulls.shouldNotBeNull
+import io.kotest.matchers.shouldBe
+import io.mockk.every
+import io.mockk.mockk
+import org.junit.jupiter.api.Nested
+import org.junit.jupiter.api.Test
+import testhelpers.BaseTest
+import java.time.Instant
+
+class PodDeviceCacheTest : BaseTest() {
+
+    private val fiveMinAgo = Instant.parse("2026-03-31T11:55:00Z")
+    private val oneHourAgo = Instant.parse("2026-03-31T11:00:00Z")
+
+    private val cachedState = CachedDeviceState(
+        profileId = "test-profile",
+        model = PodModel.AIRPODS_PRO3,
+        address = "AA:BB:CC:DD:EE:FF",
+        left = CachedDeviceState.CachedBatterySlot(0.8f, fiveMinAgo),
+        right = CachedDeviceState.CachedBatterySlot(0.7f, fiveMinAgo),
+        case = CachedDeviceState.CachedBatterySlot(0.5f, oneHourAgo),
+        headset = null,
+        isLeftCharging = false,
+        isRightCharging = false,
+        isCaseCharging = true,
+        lastSeenAt = fiveMinAgo,
+    )
+
+    /**
+     * DualApplePods extends DualBlePodSnapshot, HasCase, HasChargeDetectionDual, etc.
+     * Using it as the mock type ensures all interface casts in PodDevice work correctly.
+     */
+    private fun mockDualPod(
+        leftBattery: Float? = null,
+        rightBattery: Float? = null,
+        caseBattery: Float? = null,
+    ): DualApplePods = mockk(relaxed = true) {
+        every { batteryLeftPodPercent } returns leftBattery
+        every { batteryRightPodPercent } returns rightBattery
+        every { batteryCasePercent } returns caseBattery
+        every { model } returns PodModel.AIRPODS_PRO3
+    }
+
+    @Nested
+    inner class CacheFallback {
+
+        @Test
+        fun `battery falls back to cache when live sources are null`() {
+            val device = PodDevice(profileId = "test-profile", ble = null, aap = null, cached = cachedState)
+            device.batteryLeft shouldBe 0.8f
+            device.batteryRight shouldBe 0.7f
+            device.batteryCase shouldBe 0.5f
+            device.batteryHeadset.shouldBeNull()
+        }
+
+        @Test
+        fun `live BLE takes precedence over cache`() {
+            val device = PodDevice(
+                profileId = "test-profile", ble = mockDualPod(leftBattery = 0.9f, rightBattery = 0.6f, caseBattery = 0.3f),
+                aap = null,
+                cached = cachedState,
+            )
+            device.batteryLeft shouldBe 0.9f
+            device.batteryRight shouldBe 0.6f
+            device.batteryCase shouldBe 0.3f
+        }
+
+        @Test
+        fun `live AAP takes precedence over both BLE and cache`() {
+            val aapState = AapPodState(
+                batteries = mapOf(
+                    AapPodState.BatteryType.LEFT to AapPodState.Battery(AapPodState.BatteryType.LEFT, 0.95f, AapPodState.ChargingState.NOT_CHARGING),
+                )
+            )
+            val device = PodDevice(
+                profileId = "test-profile", ble = mockDualPod(leftBattery = 0.5f),
+                aap = aapState,
+                cached = cachedState,
+            )
+            device.batteryLeft shouldBe 0.95f  // AAP wins
+            device.batteryRight shouldBe 0.7f  // BLE null -> cache
+            device.batteryCase shouldBe 0.5f   // BLE null -> cache
+        }
+
+        @Test
+        fun `charging falls back to cache`() {
+            val device = PodDevice(profileId = "test-profile", ble = null, aap = null, cached = cachedState)
+            device.isLeftPodCharging shouldBe false
+            device.isCaseCharging shouldBe true
+        }
+
+        @Test
+        fun `model falls back to cache`() {
+            val device = PodDevice(profileId = "test-profile", ble = null, aap = null, cached = cachedState)
+            device.model shouldBe PodModel.AIRPODS_PRO3
+        }
+
+        @Test
+        fun `seenLastAt falls back to cache`() {
+            val device = PodDevice(profileId = "test-profile", ble = null, aap = null, cached = cachedState)
+            device.seenLastAt shouldBe fiveMinAgo
+        }
+
+        @Test
+        fun `profileId falls back to cache`() {
+            val device = PodDevice(profileId = "test-profile", ble = null, aap = null, cached = cachedState)
+            device.profileId shouldBe "test-profile"
+        }
+    }
+
+    @Nested
+    inner class IsLive {
+
+        @Test
+        fun `isLive true when BLE present`() {
+            val device = PodDevice(profileId = "test-profile", ble = mockDualPod(), aap = null, cached = cachedState)
+            device.isLive shouldBe true
+        }
+
+        @Test
+        fun `isLive true when AAP present`() {
+            val device = PodDevice(profileId = "test-profile", ble = null, aap = AapPodState(), cached = cachedState)
+            device.isLive shouldBe true
+        }
+
+        @Test
+        fun `isLive false when only cache`() {
+            val device = PodDevice(profileId = "test-profile", ble = null, aap = null, cached = cachedState)
+            device.isLive shouldBe false
+        }
+    }
+
+    @Nested
+    inner class StalenessDetection {
+
+        @Test
+        fun `isBatteryCached true when all live null and cache has values`() {
+            val device = PodDevice(profileId = "test-profile", ble = null, aap = null, cached = cachedState)
+            device.isBatteryCached shouldBe true
+        }
+
+        @Test
+        fun `isBatteryCached false when all live sources have data`() {
+            val device = PodDevice(
+                profileId = "test-profile", ble = mockDualPod(leftBattery = 0.9f, rightBattery = 0.8f, caseBattery = 0.3f),
+                aap = null,
+                cached = cachedState,
+            )
+            device.isBatteryCached shouldBe false
+        }
+
+        @Test
+        fun `isBatteryCached true when BLE present but pod batteries are null`() {
+            val device = PodDevice(
+                profileId = "test-profile", ble = mockDualPod(caseBattery = 0.4f),
+                aap = null,
+                cached = cachedState,
+            )
+            device.isBatteryCached shouldBe true
+        }
+
+        @Test
+        fun `isBatteryCached false when no cache`() {
+            val device = PodDevice(profileId = "test-profile", ble = null, aap = null, cached = null)
+            device.isBatteryCached shouldBe false
+        }
+
+        @Test
+        fun `cachedBatteryAt returns oldest cached slot timestamp`() {
+            val device = PodDevice(profileId = "test-profile", ble = null, aap = null, cached = cachedState)
+            device.cachedBatteryAt shouldBe oneHourAgo
+        }
+
+        @Test
+        fun `cachedBatteryAt null when live data covers all slots`() {
+            val device = PodDevice(
+                profileId = "test-profile", ble = mockDualPod(leftBattery = 0.9f, rightBattery = 0.8f, caseBattery = 0.3f),
+                aap = null,
+                cached = cachedState,
+            )
+            device.cachedBatteryAt.shouldBeNull()
+        }
+
+        @Test
+        fun `cachedBatteryAt returns only timestamp of slots that fell through`() {
+            val device = PodDevice(
+                profileId = "test-profile", ble = mockDualPod(caseBattery = 0.4f),
+                aap = null,
+                cached = cachedState,
+            )
+            device.cachedBatteryAt.shouldNotBeNull()
+            device.cachedBatteryAt shouldBe fiveMinAgo
+        }
+    }
+}
diff --git a/app/src/test/java/eu/darken/capod/monitor/core/PodDeviceTest.kt b/app/src/test/java/eu/darken/capod/monitor/core/PodDeviceTest.kt
index 633ba268..e1368d6c 100644
--- a/app/src/test/java/eu/darken/capod/monitor/core/PodDeviceTest.kt
+++ b/app/src/test/java/eu/darken/capod/monitor/core/PodDeviceTest.kt
@@ -41,7 +41,7 @@ class PodDeviceTest : BaseTest() {
 
     @Test
     fun `BLE-only device exposes battery from BLE`() {
-        val device = PodDevice(ble = mockDualPod(leftBattery = 0.8f), aap = null)
+        val device = PodDevice(profileId = null, ble = mockDualPod(leftBattery = 0.8f), aap = null)
         device.batteryLeft shouldBe 0.8f
         device.isAapConnected shouldBe false
     }
@@ -49,7 +49,7 @@ class PodDeviceTest : BaseTest() {
     @Test
     fun `capabilities come from model features`() {
         val device = PodDevice(
-            ble = mockDualPod(model = PodModel.AIRPODS_PRO3),
+            profileId = null, ble = mockDualPod(model = PodModel.AIRPODS_PRO3),
             aap = null,
         )
         device.hasDualPods shouldBe true
@@ -61,7 +61,7 @@ class PodDeviceTest : BaseTest() {
     @Test
     fun `Beats Solo 3 has no dual pods or case`() {
         val device = PodDevice(
-            ble = mockk(relaxed = true) { every { model } returns PodModel.BEATS_SOLO_3 },
+            profileId = null, ble = mockk(relaxed = true) { every { model } returns PodModel.BEATS_SOLO_3 },
             aap = null,
         )
         device.hasDualPods shouldBe false
@@ -79,7 +79,7 @@ class PodDeviceTest : BaseTest() {
                 ),
             ),
         )
-        val device = PodDevice(ble = mockDualPod(), aap = aap)
+        val device = PodDevice(profileId = null, ble = mockDualPod(), aap = aap)
         device.isAapConnected shouldBe true
         device.ancMode.shouldNotBeNull()
         device.ancMode!!.current shouldBe AapSetting.AncMode.Value.TRANSPARENCY
@@ -87,36 +87,32 @@ class PodDeviceTest : BaseTest() {
 
     @Test
     fun `ANC mode is null when not AAP connected`() {
-        val device = PodDevice(ble = mockDualPod(), aap = null)
+        val device = PodDevice(profileId = null, ble = mockDualPod(), aap = null)
         device.ancMode.shouldBeNull()
     }
 
     @Test
     fun `null BLE gives UNKNOWN model`() {
-        val device = PodDevice(ble = null, aap = null)
+        val device = PodDevice(profileId = null, ble = null, aap = null)
         device.model shouldBe PodModel.UNKNOWN
     }
 
     @Test
-    fun `identity properties delegate to BLE`() {
+    fun `identifier delegates to BLE`() {
         val id = BlePodSnapshot.Id()
-        val meta = mockk<BlePodSnapshot.Meta>(relaxed = true)
         val device = PodDevice(
-            ble = mockk(relaxed = true) {
+            profileId = null, ble = mockk(relaxed = true) {
                 every { identifier } returns id
-                every { this@mockk.meta } returns meta
             },
             aap = null,
         )
         device.identifier shouldBe id
-        device.meta shouldBe meta
     }
 
     @Test
-    fun `identity properties null when BLE null`() {
-        val device = PodDevice(ble = null, aap = null)
+    fun `identifier null when BLE null`() {
+        val device = PodDevice(profileId = null, ble = null, aap = null)
         device.identifier.shouldBeNull()
-        device.meta.shouldBeNull()
     }
 
     @Test
@@ -124,7 +120,7 @@ class PodDeviceTest : BaseTest() {
         val now = Instant.now()
         val earlier = now.minusSeconds(60)
         val device = PodDevice(
-            ble = mockk(relaxed = true) {
+            profileId = null, ble = mockk(relaxed = true) {
                 every { seenLastAt } returns now
                 every { seenFirstAt } returns earlier
                 every { signalQuality } returns 0.75f
@@ -140,7 +136,7 @@ class PodDeviceTest : BaseTest() {
 
     @Test
     fun `signal timing defaults when BLE null`() {
-        val device = PodDevice(ble = null, aap = null)
+        val device = PodDevice(profileId = null, ble = null, aap = null)
         device.seenLastAt.shouldBeNull()
         device.seenFirstAt.shouldBeNull()
         device.signalQuality shouldBe 0f
@@ -155,7 +151,7 @@ class PodDeviceTest : BaseTest() {
             every { (this@mockk as HasChargeDetectionDual).isRightPodCharging } returns false
             every { (this@mockk as HasCase).isCaseCharging } returns true
         }
-        val device = PodDevice(ble = mock, aap = null)
+        val device = PodDevice(profileId = null, ble = mock, aap = null)
         device.isLeftPodCharging shouldBe true
         device.isRightPodCharging shouldBe false
         device.isCaseCharging shouldBe true
@@ -170,7 +166,7 @@ class PodDeviceTest : BaseTest() {
             every { (this@mockk as HasEarDetection).isBeingWorn } returns false
             every { (this@mockk as HasEarDetectionDual).isEitherPodInEar } returns true
         }
-        val device = PodDevice(ble = mock, aap = null)
+        val device = PodDevice(profileId = null, ble = mock, aap = null)
         device.isLeftInEar shouldBe true
         device.isRightInEar shouldBe false
         device.isBeingWorn shouldBe false
@@ -192,7 +188,7 @@ class PodDeviceTest : BaseTest() {
                 ),
             ),
         )
-        val device = PodDevice(ble = mock, aap = aap)
+        val device = PodDevice(profileId = null, ble = mock, aap = aap)
         device.isEitherPodInEar shouldBe true
     }
 
@@ -203,7 +199,7 @@ class PodDeviceTest : BaseTest() {
             every { (this@mockk as HasEarDetectionDual).isEitherPodInEar } returns true
         }
         val aap = AapPodState(connectionState = AapPodState.ConnectionState.READY)
-        val device = PodDevice(ble = mock, aap = aap)
+        val device = PodDevice(profileId = null, ble = mock, aap = aap)
         device.isEitherPodInEar shouldBe true
     }
 
@@ -222,7 +218,7 @@ class PodDeviceTest : BaseTest() {
                 ),
             ),
         )
-        val device = PodDevice(ble = mock, aap = aap)
+        val device = PodDevice(profileId = null, ble = mock, aap = aap)
         device.isLeftInEar shouldBe true
         device.isRightInEar shouldBe false
     }
@@ -242,7 +238,7 @@ class PodDeviceTest : BaseTest() {
                 ),
             ),
         )
-        val device = PodDevice(ble = mock, aap = aap)
+        val device = PodDevice(profileId = null, ble = mock, aap = aap)
         device.isLeftInEar shouldBe false
         device.isRightInEar shouldBe true
     }
@@ -261,7 +257,7 @@ class PodDeviceTest : BaseTest() {
                 ),
             ),
         )
-        val device = PodDevice(ble = mock, aap = aap)
+        val device = PodDevice(profileId = null, ble = mock, aap = aap)
         device.isBeingWorn shouldBe true
     }
 
@@ -279,7 +275,7 @@ class PodDeviceTest : BaseTest() {
                 ),
             ),
         )
-        val device = PodDevice(ble = mock, aap = aap)
+        val device = PodDevice(profileId = null, ble = mock, aap = aap)
         device.isBeingWorn shouldBe false
     }
 
@@ -301,7 +297,7 @@ class PodDeviceTest : BaseTest() {
                 AapSetting.PrimaryPod::class to AapSetting.PrimaryPod(AapSetting.PrimaryPod.Pod.LEFT),
             ),
         )
-        val device = PodDevice(ble = mock, aap = aap)
+        val device = PodDevice(profileId = null, ble = mock, aap = aap)
         device.isLeftInEar shouldBe true
         device.isRightInEar shouldBe false
     }
@@ -322,7 +318,7 @@ class PodDeviceTest : BaseTest() {
                 AapSetting.PrimaryPod::class to AapSetting.PrimaryPod(AapSetting.PrimaryPod.Pod.LEFT), // AAP says LEFT
             ),
         )
-        val device = PodDevice(ble = mock, aap = aap)
+        val device = PodDevice(profileId = null, ble = mock, aap = aap)
         device.isLeftInEar shouldBe true  // AAP wins
         device.isRightInEar shouldBe false
     }
@@ -343,7 +339,7 @@ class PodDeviceTest : BaseTest() {
                 // No PrimaryPod setting — falls back to BLE
             ),
         )
-        val device = PodDevice(ble = mock, aap = aap)
+        val device = PodDevice(profileId = null, ble = mock, aap = aap)
         device.isLeftInEar shouldBe false
         device.isRightInEar shouldBe true  // BLE says RIGHT is primary
     }
@@ -361,7 +357,7 @@ class PodDeviceTest : BaseTest() {
                 AapSetting.PrimaryPod::class to AapSetting.PrimaryPod(AapSetting.PrimaryPod.Pod.LEFT),
             ),
         )
-        val device = PodDevice(ble = mock, aap = aap)
+        val device = PodDevice(profileId = null, ble = mock, aap = aap)
         device.isLeftPodMicrophone shouldBe true   // AAP says LEFT
         device.isRightPodMicrophone shouldBe false
     }
@@ -374,7 +370,7 @@ class PodDeviceTest : BaseTest() {
             every { isRightPodMicrophone } returns true
         }
         val aap = AapPodState(connectionState = AapPodState.ConnectionState.READY)
-        val device = PodDevice(ble = mock, aap = aap)
+        val device = PodDevice(profileId = null, ble = mock, aap = aap)
         device.isLeftPodMicrophone shouldBe false
         device.isRightPodMicrophone shouldBe true  // BLE fallback
     }
@@ -394,7 +390,7 @@ class PodDeviceTest : BaseTest() {
                 AapSetting.PrimaryPod::class to AapSetting.PrimaryPod(AapSetting.PrimaryPod.Pod.RIGHT),
             ),
         )
-        val device = PodDevice(ble = mock, aap = aap)
+        val device = PodDevice(profileId = null, ble = mock, aap = aap)
         device.isLeftPodMicrophone shouldBe false
         device.isRightPodMicrophone shouldBe true
     }
@@ -414,7 +410,7 @@ class PodDeviceTest : BaseTest() {
                 AapSetting.PrimaryPod::class to AapSetting.PrimaryPod(AapSetting.PrimaryPod.Pod.LEFT),
             ),
         )
-        val device = PodDevice(ble = mock, aap = aap)
+        val device = PodDevice(profileId = null, ble = mock, aap = aap)
         device.isLeftPodMicrophone shouldBe true
         device.isRightPodMicrophone shouldBe false
     }
@@ -425,27 +421,27 @@ class PodDeviceTest : BaseTest() {
             connectionState = AapPodState.ConnectionState.READY,
             pendingAncMode = AapSetting.AncMode.Value.ADAPTIVE,
         )
-        val device = PodDevice(ble = mockDualPod(), aap = aap)
+        val device = PodDevice(profileId = null, ble = mockDualPod(), aap = aap)
         device.pendingAncMode shouldBe AapSetting.AncMode.Value.ADAPTIVE
     }
 
     @Test
     fun `pendingAncMode null when no AAP`() {
-        val device = PodDevice(ble = mockDualPod(), aap = null)
+        val device = PodDevice(profileId = null, ble = mockDualPod(), aap = null)
         device.pendingAncMode.shouldBeNull()
     }
 
     @Test
     fun `pendingAncMode null when not set`() {
         val aap = AapPodState(connectionState = AapPodState.ConnectionState.READY)
-        val device = PodDevice(ble = mockDualPod(), aap = aap)
+        val device = PodDevice(profileId = null, ble = mockDualPod(), aap = aap)
         device.pendingAncMode.shouldBeNull()
     }
 
     @Test
     fun `icon and label properties delegate to BLE`() {
         val device = PodDevice(
-            ble = mockk(relaxed = true) {
+            profileId = null, ble = mockk(relaxed = true) {
                 every { model } returns PodModel.AIRPODS_PRO3
                 every { iconRes } returns 42
             },
@@ -456,14 +452,14 @@ class PodDeviceTest : BaseTest() {
 
     @Test
     fun `rawDataHex empty when BLE null`() {
-        val device = PodDevice(ble = null, aap = null)
+        val device = PodDevice(profileId = null, ble = null, aap = null)
         device.rawDataHex shouldBe emptyList()
     }
 
     @Test
     fun `battery falls back to BLE when AAP battery is null`() {
         val aap = AapPodState(connectionState = AapPodState.ConnectionState.READY)
-        val device = PodDevice(ble = mockDualPod(leftBattery = 0.8f), aap = aap)
+        val device = PodDevice(profileId = null, ble = mockDualPod(leftBattery = 0.8f), aap = aap)
         device.batteryLeft shouldBe 0.8f
         device.isAapConnected shouldBe true
     }
@@ -476,7 +472,7 @@ class PodDeviceTest : BaseTest() {
                 AapPodState.BatteryType.LEFT to AapPodState.Battery(AapPodState.BatteryType.LEFT, 0.79f, AapPodState.ChargingState.NOT_CHARGING),
             ),
         )
-        val device = PodDevice(ble = mockDualPod(leftBattery = 0.8f), aap = aap)
+        val device = PodDevice(profileId = null, ble = mockDualPod(leftBattery = 0.8f), aap = aap)
         device.batteryLeft shouldBe 0.79f  // AAP 1% granularity wins over BLE 10%
     }
 
@@ -492,7 +488,7 @@ class PodDeviceTest : BaseTest() {
                 AapPodState.BatteryType.LEFT to AapPodState.Battery(AapPodState.BatteryType.LEFT, 0.8f, AapPodState.ChargingState.CHARGING_OPTIMIZED),
             ),
         )
-        val device = PodDevice(ble = mock, aap = aap)
+        val device = PodDevice(profileId = null, ble = mock, aap = aap)
         device.isLeftPodCharging shouldBe true  // AAP CHARGING_OPTIMIZED counts as charging
     }
 
@@ -508,7 +504,7 @@ class PodDeviceTest : BaseTest() {
             every { this@mockk.address } returns bleRpa
             every { meta } returns ApplePods.AppleMeta(profile = profile)
         }
-        val device = PodDevice(ble = ble, aap = null)
+        val device = PodDevice(profileId = null, ble = ble, aap = null)
         device.address shouldBe bondedAddress
         device.bleAddress shouldBe bleRpa
     }
@@ -520,7 +516,7 @@ class PodDeviceTest : BaseTest() {
             every { model } returns PodModel.AIRPODS_PRO3
             every { signalQuality } returns bleQuality
         }
-        return PodDevice(ble = ble, aap = aap)
+        return PodDevice(profileId = null, ble = ble, aap = aap)
     }
 
     @Test
@@ -627,13 +623,13 @@ class PodDeviceTest : BaseTest() {
 
     @Test
     fun `bleKeyState - null BLE returns NONE`() {
-        val device = PodDevice(ble = null, aap = null)
+        val device = PodDevice(profileId = null, ble = null, aap = null)
         device.bleKeyState shouldBe BleKeyState.NONE
     }
 
     @Test
     fun `bleKeyState - non-Apple BLE returns NONE`() {
-        val device = PodDevice(ble = mockk(relaxed = true) { every { model } returns PodModel.UNKNOWN }, aap = null)
+        val device = PodDevice(profileId = null, ble = mockk(relaxed = true) { every { model } returns PodModel.UNKNOWN }, aap = null)
         device.bleKeyState shouldBe BleKeyState.NONE
     }
 
@@ -644,7 +640,7 @@ class PodDeviceTest : BaseTest() {
             every { meta } returns ApplePods.AppleMeta(isIRKMatch = false)
             every { payload } returns ProximityPayload(public = ProximityPayload.Public(UByteArray(9)), private = null)
         }
-        val device = PodDevice(ble = ble, aap = null)
+        val device = PodDevice(profileId = null, ble = ble, aap = null)
         device.bleKeyState shouldBe BleKeyState.NONE
     }
 
@@ -655,7 +651,7 @@ class PodDeviceTest : BaseTest() {
             every { meta } returns ApplePods.AppleMeta(isIRKMatch = true)
             every { payload } returns ProximityPayload(public = ProximityPayload.Public(UByteArray(9)), private = null)
         }
-        val device = PodDevice(ble = ble, aap = null)
+        val device = PodDevice(profileId = null, ble = ble, aap = null)
         device.bleKeyState shouldBe BleKeyState.IRK_ONLY
     }
 
@@ -669,7 +665,7 @@ class PodDeviceTest : BaseTest() {
                 private = ProximityPayload.Private(UByteArray(8)),
             )
         }
-        val device = PodDevice(ble = ble, aap = null)
+        val device = PodDevice(profileId = null, ble = ble, aap = null)
         device.bleKeyState shouldBe BleKeyState.IRK_AND_ENCRYPTED
     }
 }
diff --git a/app/src/test/java/eu/darken/capod/monitor/core/cache/ToCachedStateTest.kt b/app/src/test/java/eu/darken/capod/monitor/core/cache/ToCachedStateTest.kt
new file mode 100644
index 00000000..c6c8aef6
--- /dev/null
+++ b/app/src/test/java/eu/darken/capod/monitor/core/cache/ToCachedStateTest.kt
@@ -0,0 +1,138 @@
+package eu.darken.capod.monitor.core.cache
+
+import eu.darken.capod.monitor.core.PodDevice
+import eu.darken.capod.pods.core.apple.PodModel
+import eu.darken.capod.pods.core.apple.ble.devices.DualApplePods
+import io.kotest.matchers.nulls.shouldBeNull
+import io.kotest.matchers.nulls.shouldNotBeNull
+import io.kotest.matchers.shouldBe
+import io.mockk.every
+import io.mockk.mockk
+import org.junit.jupiter.api.Nested
+import org.junit.jupiter.api.Test
+import testhelpers.BaseTest
+import java.time.Instant
+
+class ToCachedStateTest : BaseTest() {
+
+    private val now = Instant.parse("2026-04-02T12:00:00Z")
+
+    private fun mockDualPod(
+        leftBattery: Float? = null,
+        rightBattery: Float? = null,
+        caseBattery: Float? = null,
+    ): DualApplePods = mockk(relaxed = true) {
+        every { batteryLeftPodPercent } returns leftBattery
+        every { batteryRightPodPercent } returns rightBattery
+        every { batteryCasePercent } returns caseBattery
+        every { model } returns PodModel.AIRPODS_PRO3
+        every { seenLastAt } returns now
+    }
+
+    private fun liveDevice(
+        leftBattery: Float? = 0.8f,
+        rightBattery: Float? = 0.7f,
+        caseBattery: Float? = 0.5f,
+    ) = PodDevice(
+        profileId = "test-profile",
+        ble = mockDualPod(leftBattery, rightBattery, caseBattery),
+        aap = null,
+    )
+
+    @Nested
+    inner class Creates {
+
+        @Test
+        fun `creates cached state from live device with battery`() {
+            val result = liveDevice().toCachedState(existing = null, now = now)
+            result.shouldNotBeNull()
+            result.profileId shouldBe "test-profile"
+            result.left?.percent shouldBe 0.8f
+            result.right?.percent shouldBe 0.7f
+            result.case?.percent shouldBe 0.5f
+            result.lastSeenAt shouldBe now
+        }
+
+        @Test
+        fun `preserves existing slots when live value is null`() {
+            val existing = CachedDeviceState(
+                profileId = "test-profile",
+                model = PodModel.AIRPODS_PRO3,
+                left = CachedDeviceState.CachedBatterySlot(0.9f, now.minusSeconds(60)),
+                lastSeenAt = now.minusSeconds(120),
+            )
+            val result = liveDevice(leftBattery = null, caseBattery = 0.6f).toCachedState(existing, now)
+            result.shouldNotBeNull()
+            result.left?.percent shouldBe 0.9f
+            result.case?.percent shouldBe 0.6f
+        }
+    }
+
+    @Nested
+    inner class Skips {
+
+        @Test
+        fun `returns null for cached-only device`() {
+            val device = PodDevice(profileId = "test-profile", ble = null, aap = null, cached = mockk(relaxed = true))
+            device.toCachedState(existing = null, now = now).shouldBeNull()
+        }
+
+        @Test
+        fun `returns null when no profile`() {
+            val device = PodDevice(profileId = null, ble = mockDualPod(caseBattery = 0.5f), aap = null)
+            device.toCachedState(existing = null, now = now).shouldBeNull()
+        }
+
+        @Test
+        fun `returns null when all battery values null`() {
+            liveDevice(leftBattery = null, rightBattery = null, caseBattery = null)
+                .toCachedState(existing = null, now = now)
+                .shouldBeNull()
+        }
+
+        @Test
+        fun `returns null when state unchanged`() {
+            val existing = CachedDeviceState(
+                profileId = "test-profile",
+                model = PodModel.AIRPODS_PRO3,
+                left = CachedDeviceState.CachedBatterySlot(0.8f, now),
+                right = CachedDeviceState.CachedBatterySlot(0.7f, now),
+                case = CachedDeviceState.CachedBatterySlot(0.5f, now),
+                isLeftCharging = false,
+                isRightCharging = false,
+                isCaseCharging = false,
+                isHeadsetCharging = false,
+                lastSeenAt = now,
+            )
+            liveDevice().toCachedState(existing, now).shouldBeNull()
+        }
+
+        @Test
+        fun `returns new state when battery changed`() {
+            val existing = CachedDeviceState(
+                profileId = "test-profile",
+                model = PodModel.AIRPODS_PRO3,
+                left = CachedDeviceState.CachedBatterySlot(0.9f, now),
+                lastSeenAt = now,
+            )
+            liveDevice(leftBattery = 0.8f).toCachedState(existing, now).shouldNotBeNull()
+        }
+
+        @Test
+        fun `returns new state when lastSeenAt drifted over 1 minute`() {
+            val existing = CachedDeviceState(
+                profileId = "test-profile",
+                model = PodModel.AIRPODS_PRO3,
+                left = CachedDeviceState.CachedBatterySlot(0.8f, now.minusSeconds(120)),
+                right = CachedDeviceState.CachedBatterySlot(0.7f, now.minusSeconds(120)),
+                case = CachedDeviceState.CachedBatterySlot(0.5f, now.minusSeconds(120)),
+                isLeftCharging = false,
+                isRightCharging = false,
+                isCaseCharging = false,
+                isHeadsetCharging = false,
+                lastSeenAt = now.minusSeconds(120),
+            )
+            liveDevice().toCachedState(existing, now).shouldNotBeNull()
+        }
+    }
+}
diff --git a/app/src/test/java/eu/darken/capod/reaction/core/aap/AapAutoConnectTest.kt b/app/src/test/java/eu/darken/capod/reaction/core/aap/AapAutoConnectTest.kt
index 8b573892..d46d1c69 100644
--- a/app/src/test/java/eu/darken/capod/reaction/core/aap/AapAutoConnectTest.kt
+++ b/app/src/test/java/eu/darken/capod/reaction/core/aap/AapAutoConnectTest.kt
@@ -2,12 +2,12 @@ package eu.darken.capod.reaction.core.aap
 
 import eu.darken.capod.common.bluetooth.BluetoothDevice2
 import eu.darken.capod.common.bluetooth.BluetoothManager2
-import eu.darken.capod.monitor.core.BlePodMonitor
-import eu.darken.capod.pods.core.apple.ble.BlePodSnapshot
+import eu.darken.capod.monitor.core.ble.BlePodMonitor
 import eu.darken.capod.pods.core.apple.PodModel
 import eu.darken.capod.pods.core.apple.aap.AapConnectionManager
 import eu.darken.capod.pods.core.apple.aap.AapPodState
 import eu.darken.capod.pods.core.apple.aap.protocol.AapDeviceInfo
+import eu.darken.capod.pods.core.apple.ble.BlePodSnapshot
 import eu.darken.capod.profiles.core.AppleDeviceProfile
 import eu.darken.capod.profiles.core.DeviceProfile
 import eu.darken.capod.profiles.core.DeviceProfilesRepo