diff --git a/app/src/main/java/ink/trmnl/android/data/TrmnlDeviceConfigDataStore.kt b/app/src/main/java/ink/trmnl/android/data/TrmnlDeviceConfigDataStore.kt
index c11b629..bc575b7 100644
--- a/app/src/main/java/ink/trmnl/android/data/TrmnlDeviceConfigDataStore.kt
+++ b/app/src/main/java/ink/trmnl/android/data/TrmnlDeviceConfigDataStore.kt
@@ -99,8 +99,6 @@ class TrmnlDeviceConfigDataStore
             private val CONFIG_JSON_KEY = stringPreferencesKey("config_json")
             private val DEVICE_MAC_ID_KEY = stringPreferencesKey("device_mac_id")
             private val IS_MASTER_DEVICE_KEY = stringPreferencesKey("is_master_device")
-            private val USER_API_TOKEN_KEY = stringPreferencesKey("user_api_token")
-            private val DEVICE_ID_KEY = stringPreferencesKey("device_id")
             private val DEVICE_MODEL_PREFERENCES_KEY = stringPreferencesKey("device_model_preferences")
         }
 
@@ -238,7 +236,7 @@ class TrmnlDeviceConfigDataStore
                     try {
                         val config: TrmnlDeviceConfig? = deviceConfigAdapter.fromJson(configJson)
                         Timber.tag(TAG).d(
-                            "Loading device config (JSON): type=${config?.type}, userApiToken=${config?.userApiToken.obfuscated()}",
+                            "Loading device config (JSON): type=${config?.type}",
                         )
                         config
                     } catch (e: Exception) {
@@ -261,11 +259,9 @@ class TrmnlDeviceConfigDataStore
                     val refreshRate = preferences[REFRESH_RATE_SEC_KEY] ?: DEFAULT_REFRESH_INTERVAL_SEC
                     val deviceMacId = preferences[DEVICE_MAC_ID_KEY]
                     val isMasterDevice = preferences[IS_MASTER_DEVICE_KEY]?.toBoolean()
-                    val userApiToken = preferences[USER_API_TOKEN_KEY]
-                    val deviceId = preferences[DEVICE_ID_KEY]?.toIntOrNull()
 
                     Timber.tag(TAG).d(
-                        "Loading device config (legacy): type=$type, deviceApiToken=${token.obfuscated()}, deviceId=$deviceId",
+                        "Loading device config (legacy): type=$type, deviceApiToken=${token.obfuscated()}",
                     )
 
                     if (token != null) {
@@ -276,8 +272,6 @@ class TrmnlDeviceConfigDataStore
                             deviceMacId = deviceMacId,
                             refreshRateSecs = refreshRate,
                             isMasterDevice = isMasterDevice,
-                            userApiToken = userApiToken,
-                            deviceId = deviceId,
                         )
                     } else {
                         null
@@ -311,7 +305,7 @@ class TrmnlDeviceConfigDataStore
         suspend fun saveDeviceConfig(config: TrmnlDeviceConfig) {
             try {
                 Timber.tag(TAG).d(
-                    "Saving device config: type=${config.type}, userApiToken=${config.userApiToken.obfuscated()}",
+                    "Saving device config: type=${config.type}",
                 )
                 val configJson = deviceConfigAdapter.toJson(config)
                 context.deviceConfigStore.edit { preferences ->
@@ -333,16 +327,6 @@ class TrmnlDeviceConfigDataStore
                     config.isMasterDevice?.let { isMaster ->
                         preferences[IS_MASTER_DEVICE_KEY] = isMaster.toString()
                     } ?: preferences.remove(IS_MASTER_DEVICE_KEY)
-
-                    // Save userApiToken if available
-                    config.userApiToken?.let { userToken ->
-                        preferences[USER_API_TOKEN_KEY] = userToken
-                    } ?: preferences.remove(USER_API_TOKEN_KEY)
-
-                    // Save deviceId if available
-                    config.deviceId?.let { deviceId ->
-                        preferences[DEVICE_ID_KEY] = deviceId.toString()
-                    } ?: preferences.remove(DEVICE_ID_KEY)
                 }
                 Timber.tag(TAG).d("Device config saved successfully")
             } catch (e: Exception) {
@@ -359,56 +343,6 @@ class TrmnlDeviceConfigDataStore
             }
         }
 
-        /**
-         * Saves the user-level API token (Account API key)
-         */
-        suspend fun saveUserApiToken(token: String) {
-            Timber.tag(TAG).d("Saving user API token: ${token.obfuscated()}")
-            context.deviceConfigStore.edit { preferences ->
-                preferences[USER_API_TOKEN_KEY] = token
-            }
-            Timber.tag(TAG).d("User API token saved successfully")
-        }
-
-        /**
-         * Gets the user-level API token
-         */
-        suspend fun getUserApiToken(): String? {
-            val token =
-                context.deviceConfigStore.data
-                    .map { preferences -> preferences[USER_API_TOKEN_KEY] }
-                    .first()
-            Timber.tag(TAG).d("Retrieved user API token: ${token.obfuscated()}")
-            return token
-        }
-
-        /**
-         * Saves the device ID (TRMNL device ID from /api/devices/me).
-         *
-         * **Note:** This is only applicable for BYOD device types.
-         */
-        suspend fun saveDeviceId(deviceId: Int) {
-            Timber.tag(TAG).d("Saving device ID: $deviceId")
-            context.deviceConfigStore.edit { preferences ->
-                preferences[DEVICE_ID_KEY] = deviceId.toString()
-            }
-            Timber.tag(TAG).d("Device ID saved successfully")
-        }
-
-        /**
-         * Gets the device ID.
-         *
-         * **Note:** This is only applicable for BYOD device types.
-         */
-        suspend fun getDeviceId(): Int? {
-            val deviceId =
-                context.deviceConfigStore.data
-                    .map { preferences -> preferences[DEVICE_ID_KEY]?.toIntOrNull() }
-                    .first()
-            Timber.tag(TAG).d("Retrieved device ID: $deviceId")
-            return deviceId
-        }
-
         /**
          * Saves the access token
          */
diff --git a/app/src/main/java/ink/trmnl/android/data/TrmnlDisplayRepository.kt b/app/src/main/java/ink/trmnl/android/data/TrmnlDisplayRepository.kt
index 0b11321..3669002 100644
--- a/app/src/main/java/ink/trmnl/android/data/TrmnlDisplayRepository.kt
+++ b/app/src/main/java/ink/trmnl/android/data/TrmnlDisplayRepository.kt
@@ -15,11 +15,8 @@ import ink.trmnl.android.network.TrmnlApiService.Companion.CURRENT_PLAYLIST_SCRE
 import ink.trmnl.android.network.TrmnlApiService.Companion.MODELS_API_PATH
 import ink.trmnl.android.network.TrmnlApiService.Companion.NEXT_PLAYLIST_SCREEN_API_PATH
 import ink.trmnl.android.network.TrmnlUserApiService
-import ink.trmnl.android.network.TrmnlUserApiService.Companion.DEVICE_API_PATH
 import ink.trmnl.android.network.TrmnlUserApiService.Companion.USER_INFO_API_PATH
-import ink.trmnl.android.network.model.TrmnlDevice
 import ink.trmnl.android.network.model.TrmnlDeviceModel
-import ink.trmnl.android.network.model.TrmnlDeviceUpdateRequest
 import ink.trmnl.android.network.model.TrmnlDisplayResponse
 import ink.trmnl.android.network.model.TrmnlUser
 import ink.trmnl.android.network.util.constructApiUrl
@@ -82,6 +79,17 @@ class TrmnlDisplayRepository
                             } else {
                                 null
                             },
+                        percentCharged =
+                            if (trmnlDeviceConfig.type == TrmnlDeviceType.BYOD) {
+                                // Send battery percentage if available for BYOD devices only
+                                // See following for context:
+                                // https://github.com/usetrmnl/trmnl-android/issues/252
+                                // https://github.com/usetrmnl/trmnl-android/issues/239
+                                // https://discord.com/channels/1281055965508141100/1466030731770855434/1469103763846463620
+                                androidDeviceInfoProvider.getBatteryLevel()
+                            } else {
+                                null
+                            },
                     )
 
             when (result) {
@@ -384,6 +392,12 @@ class TrmnlDisplayRepository
         /**
          * Fetches the device ID from the TRMNL API using the device API token.
          *
+         * **DEPRECATED:** Device ID fetching is no longer needed. Battery reporting now uses
+         * the Percent-Charged header in /api/display call, which only requires device-level
+         * authentication (Access-Token), not user-level authentication or device ID.
+         *
+         * This method will be removed in a future version.
+         *
          * This method calls the /api/devices/me endpoint with device-level authentication
          * to retrieve device information including the device ID, which is needed for
          * user-level API calls to /api/devices/{id}.
@@ -394,7 +408,17 @@ class TrmnlDisplayRepository
          * @param config Device configuration containing the device API token
          * @return A Result containing the device ID on success or an exception on failure
          */
+        @Deprecated("Device ID no longer needed for battery reporting. Use Percent-Charged header instead.")
         suspend fun getDeviceIdFromApi(config: TrmnlDeviceConfig): Result<Int> {
+            Timber.w("getDeviceIdFromApi is deprecated. Device ID is no longer needed for battery reporting.")
+            return Result.failure(
+                UnsupportedOperationException(
+                    "Device ID fetching is deprecated. Battery reporting now uses Percent-Charged header " +
+                        "in /api/display, which doesn't require device ID or user API token.",
+                ),
+            )
+
+            /* DISABLED - Device ID no longer needed for battery reporting
             Timber.i("Fetching device ID from API for device type: ${config.type}")
 
             // Always use mocked response since the endpoint doesn't exist yet
@@ -410,7 +434,7 @@ class TrmnlDisplayRepository
                     sleepModeEnabled = false,
                     sleepStartTime = 1320,
                     sleepEndTime = 480,
-                    percentCharged = 100.0,
+                    percentCharged = 100,
                     wifiStrength = 100.0,
                 )
 
@@ -438,20 +462,29 @@ class TrmnlDisplayRepository
              *     }
              * }
              */
+             */
         }
 
         /**
          * Reports the device's battery status to the TRMNL API for BYOD devices.
          *
-         * This is a convenience method that checks if the device is a BYOD device with the necessary
-         * configuration (deviceId and userApiToken), retrieves the current battery level,
-         * and reports it to the server.
+         * **DEPRECATED:** Battery reporting now uses the Percent-Charged header in /api/display call.
+         * This method is disabled and will be removed in a future version.
          *
-         * This method should be called after successful image refresh operations.
+         * Battery percentage is now automatically sent via the Percent-Charged header parameter
+         * when calling getNextDisplayData() for BYOD devices, eliminating the need for a separate
+         * API call and user-level authentication.
          *
          * @param config Device configuration containing device type, device ID, and user API token
+         * @see getNextDisplayData
          */
+        @Deprecated("Battery reporting now uses Percent-Charged header. This method is no longer needed.")
         suspend fun reportDeviceBatteryStatus(config: TrmnlDeviceConfig) {
+            // DEPRECATED: Battery reporting now happens via Percent-Charged header in /api/display
+            Timber.d("Battery reporting via separate API call is deprecated. Battery is now sent via Percent-Charged header.")
+            return
+
+            /* DISABLED - Battery now reported via Percent-Charged header
             // Only report battery for BYOD devices with required configuration
             if (config.type != TrmnlDeviceType.BYOD) {
                 Timber.d("Battery reporting skipped: not a BYOD device (type: ${config.type})")
@@ -484,25 +517,35 @@ class TrmnlDisplayRepository
             } catch (e: Exception) {
                 Timber.e(e, "Unexpected error during battery reporting")
             }
+             */
         }
 
         /**
          * Reports the device's battery status to the TRMNL API.
          *
-         * This method sends a PATCH request to /api/devices/{id} using user-level authentication
-         * to update the device's battery percentage on the server.
+         * **DEPRECATED:** This method is no longer used. Battery reporting now uses the
+         * Percent-Charged header in /api/display call instead of PATCH /api/devices/{id}.
          *
-         * This suspend function performs network I/O and should be called from a background
-         * coroutine so it does not block or delay display updates.
+         * This method will be removed in a future version.
          *
          * @param config Device configuration containing the device ID and user API token
          * @param batteryPercent The current battery percentage (0-100)
          * @return A Result containing Unit on success or an exception on failure
          */
+        @Deprecated("Battery reporting now uses Percent-Charged header. This method is no longer needed.")
         private suspend fun reportBatteryStatus(
             config: TrmnlDeviceConfig,
             batteryPercent: Int,
         ): Result<Unit> {
+            // DEPRECATED: This method is no longer used
+            Timber.d("reportBatteryStatus is deprecated and disabled")
+            return Result.failure(
+                UnsupportedOperationException(
+                    "Battery reporting via PATCH /api/devices/{id} is deprecated. Use Percent-Charged header instead.",
+                ),
+            )
+
+            /* DISABLED - Battery now reported via Percent-Charged header
             val deviceId = config.deviceId
             val userApiToken = config.userApiToken
 
@@ -524,7 +567,7 @@ class TrmnlDisplayRepository
                 return Result.success(Unit)
             }
 
-            val updateRequest = TrmnlDeviceUpdateRequest(percentCharged = batteryPercent.toDouble())
+            val updateRequest = TrmnlDeviceUpdateRequest(percentCharged = batteryPercent)
             val apiUrl = constructApiUrl(config.apiBaseUrl, DEVICE_API_PATH.replace("{id}", deviceId.toString()))
 
             val result =
@@ -545,5 +588,6 @@ class TrmnlDisplayRepository
                     Result.success(Unit)
                 }
             }
+             */
         }
     }
diff --git a/app/src/main/java/ink/trmnl/android/model/TrmnlDeviceConfig.kt b/app/src/main/java/ink/trmnl/android/model/TrmnlDeviceConfig.kt
index 4c7f89e..33926a1 100644
--- a/app/src/main/java/ink/trmnl/android/model/TrmnlDeviceConfig.kt
+++ b/app/src/main/java/ink/trmnl/android/model/TrmnlDeviceConfig.kt
@@ -33,21 +33,4 @@ data class TrmnlDeviceConfig constructor(
      * See https://github.com/usetrmnl/trmnl-android/issues/190
      */
     val isMasterDevice: Boolean? = null,
-    /**
-     * User-level API token (Account API key) for user-level endpoints.
-     * Required for BYOD devices to access user-level API endpoints like /api/me and /api/devices.
-     *
-     * This is separate from [apiAccessToken] which is the device-level API key.
-     */
-    val userApiToken: String? = null,
-    /**
-     * TRMNL device ID extracted from /api/devices/me endpoint.
-     * Used for making user-level API calls to /api/devices/{id}.
-     *
-     * This ID is fetched during BYOD device validation and is required for
-     * reporting battery status and other device-specific updates.
-     *
-     * **Note:** This field is only applicable for BYOD device types.
-     */
-    val deviceId: Int? = null,
 )
diff --git a/app/src/main/java/ink/trmnl/android/network/TrmnlApiService.kt b/app/src/main/java/ink/trmnl/android/network/TrmnlApiService.kt
index 7b815e3..9add287 100644
--- a/app/src/main/java/ink/trmnl/android/network/TrmnlApiService.kt
+++ b/app/src/main/java/ink/trmnl/android/network/TrmnlApiService.kt
@@ -94,6 +94,7 @@ interface TrmnlApiService {
      * @param deviceMacId The device's MAC address (optional)
      * @param useBase64 Whether to request Base64-encoded image data (optional)
      * @param rssi WiFi signal strength in dBm (optional, -100 to 0). See https://github.com/usetrmnl/trmnl-firmware/blob/main/src/api-client/display.cpp for additional references.
+     * @param percentCharged Battery percentage (optional, 0.0 to 100.0). Only sent for BYOD devices.
      *
      * @see getCurrentDisplayData
      */
@@ -104,6 +105,7 @@ interface TrmnlApiService {
         @Header("ID") deviceMacId: String? = null,
         @Header("BASE64") useBase64: Boolean? = null,
         @Header("RSSI") rssi: Int? = null,
+        @Header("Percent-Charged") percentCharged: Int? = null,
     ): ApiResult<TrmnlDisplayResponse, Unit>
 
     /**
diff --git a/app/src/main/java/ink/trmnl/android/network/TrmnlUserApiService.kt b/app/src/main/java/ink/trmnl/android/network/TrmnlUserApiService.kt
index dadba14..34f28ed 100644
--- a/app/src/main/java/ink/trmnl/android/network/TrmnlUserApiService.kt
+++ b/app/src/main/java/ink/trmnl/android/network/TrmnlUserApiService.kt
@@ -14,6 +14,12 @@ import retrofit2.http.Url
 /**
  * API service interface for TRMNL user-level (account) API endpoints.
  *
+ * **DEPRECATED:** This service is no longer needed for battery reporting.
+ * Battery percentage is now sent via the Percent-Charged header in /api/display call,
+ * which only requires device-level authentication (Access-Token).
+ *
+ * This interface is kept for backward compatibility and may be removed in a future version.
+ *
  * This interface defines endpoints that require user-level authentication via Bearer token
  * (Account API key), as opposed to device-level authentication.
  *
@@ -21,6 +27,10 @@ import retrofit2.http.Url
  * - https://docs.trmnl.com/go
  * - https://trmnl.com/api-docs/index.html (OpenAPI documentation)
  */
+@Deprecated(
+    message = "No longer needed for battery reporting. Battery is now sent via Percent-Charged header.",
+    level = DeprecationLevel.WARNING,
+)
 interface TrmnlUserApiService {
     companion object {
         /**
diff --git a/app/src/main/java/ink/trmnl/android/network/model/TrmnlDeviceUpdateRequest.kt b/app/src/main/java/ink/trmnl/android/network/model/TrmnlDeviceUpdateRequest.kt
index f9d5971..9e635cb 100644
--- a/app/src/main/java/ink/trmnl/android/network/model/TrmnlDeviceUpdateRequest.kt
+++ b/app/src/main/java/ink/trmnl/android/network/model/TrmnlDeviceUpdateRequest.kt
@@ -6,6 +6,11 @@ import com.squareup.moshi.JsonClass
 /**
  * Data class representing a request to update a TRMNL device.
  *
+ * **DEPRECATED:** This model is no longer needed for battery reporting.
+ * Battery percentage is now sent via the Percent-Charged header in /api/display call.
+ *
+ * This class is kept for backward compatibility and may be removed in a future version.
+ *
  * All fields are optional - only include the fields you want to update.
  *
  * Sample JSON request:
@@ -24,10 +29,14 @@ import com.squareup.moshi.JsonClass
  * @property percentCharged The battery percentage charged.
  * @see ink.trmnl.android.network.TrmnlApiService.updateDevice
  */
+@Deprecated(
+    message = "No longer needed for battery reporting. Battery is now sent via Percent-Charged header.",
+    level = DeprecationLevel.WARNING,
+)
 @JsonClass(generateAdapter = true)
 data class TrmnlDeviceUpdateRequest(
     @Json(name = "sleep_mode_enabled") val sleepModeEnabled: Boolean? = null,
     @Json(name = "sleep_start_time") val sleepStartTime: Int? = null,
     @Json(name = "sleep_end_time") val sleepEndTime: Int? = null,
-    @Json(name = "percent_charged") val percentCharged: Double? = null,
+    @Json(name = "percent_charged") val percentCharged: Int? = null,
 )
diff --git a/app/src/main/java/ink/trmnl/android/ui/settings/AppSettingsScreen.kt b/app/src/main/java/ink/trmnl/android/ui/settings/AppSettingsScreen.kt
index ea0f862..1775ee2 100644
--- a/app/src/main/java/ink/trmnl/android/ui/settings/AppSettingsScreen.kt
+++ b/app/src/main/java/ink/trmnl/android/ui/settings/AppSettingsScreen.kt
@@ -143,7 +143,6 @@ data class AppSettingsScreen(
         val accessToken: String,
         val deviceMacId: String,
         val isByodMasterDevice: Boolean,
-        val userApiToken: String,
         val usesFakeApiData: Boolean,
         val isLoading: Boolean = false,
         val validationResult: ValidationResult? = null,
@@ -197,18 +196,6 @@ data class AppSettingsScreen(
             val token: String,
         ) : Event()
 
-        /**
-         * Event triggered when the user API token is changed.
-         */
-        data class UserApiTokenChanged(
-            val token: String,
-        ) : Event()
-
-        /**
-         * Event triggered to validate the current user API token.
-         */
-        data object ValidateUserToken : Event()
-
         /**
          * Event triggered to validate the current access token.
          */
@@ -289,7 +276,6 @@ class AppSettingsPresenter
             var accessToken by remember { mutableStateOf("") }
             var deviceMacId by remember { mutableStateOf("") }
             var isByodMasterDevice by remember { mutableStateOf(true) }
-            var userApiToken by remember { mutableStateOf("") }
             var isLoading by remember { mutableStateOf(false) }
             var validationResult by remember { mutableStateOf<ValidationResult?>(null) }
             var isDeviceSetupLoading by remember { mutableStateOf(false) }
@@ -352,7 +338,6 @@ class AppSettingsPresenter
                     // Load BYOD-specific settings
                     if (it.type == TrmnlDeviceType.BYOD) {
                         isByodMasterDevice = it.isMasterDevice ?: true
-                        userApiToken = it.userApiToken ?: ""
                     }
                 }
             }
@@ -363,7 +348,6 @@ class AppSettingsPresenter
                 accessToken = accessToken,
                 deviceMacId = deviceMacId,
                 isByodMasterDevice = isByodMasterDevice,
-                userApiToken = userApiToken,
                 usesFakeApiData = usesFakeApiData,
                 isLoading = isLoading,
                 validationResult = validationResult,
@@ -380,68 +364,6 @@ class AppSettingsPresenter
                             deviceSetupMessage = null
                         }
 
-                        is AppSettingsScreen.Event.UserApiTokenChanged -> {
-                            userApiToken = event.token
-                            // Clear previous validation when user token changes
-                            if (validationResult is ValidationResult.UserTokenSuccess ||
-                                validationResult is ValidationResult.InvalidUserToken
-                            ) {
-                                validationResult = null
-                            }
-                        }
-
-                        AppSettingsScreen.Event.ValidateUserToken -> {
-                            scope.launch {
-                                focusManager.clearFocus()
-                                isLoading = true
-
-                                // Clear previous user token validation
-                                if (validationResult is ValidationResult.UserTokenSuccess ||
-                                    validationResult is ValidationResult.InvalidUserToken
-                                ) {
-                                    validationResult = null
-                                }
-
-                                // Validate user API token by calling /api/me
-                                val result =
-                                    displayRepository.validateUserApiToken(
-                                        apiBaseUrl = serverBaseUrl.forDevice(deviceType),
-                                        userApiToken = userApiToken,
-                                    )
-
-                                validationResult =
-                                    when {
-                                        result.isSuccess -> {
-                                            val user = result.getOrNull()
-                                            if (user != null) {
-                                                // Token is valid - user will save it via "Save and Continue"
-                                                ValidationResult.UserTokenSuccess(
-                                                    userName = user.name,
-                                                    userEmail = user.email,
-                                                )
-                                            } else {
-                                                Timber.e(
-                                                    "validateUserApiToken succeeded but returned null user. " +
-                                                        "apiBaseUrl=%s, deviceType=%s",
-                                                    serverBaseUrl.forDevice(deviceType),
-                                                    deviceType,
-                                                )
-                                                ValidationResult.InvalidUserToken(
-                                                    "Unexpected error: API returned success but no user data was received",
-                                                )
-                                            }
-                                        }
-                                        else -> {
-                                            ValidationResult.InvalidUserToken(
-                                                result.exceptionOrNull()?.message ?: "Invalid user API token",
-                                            )
-                                        }
-                                    }
-
-                                isLoading = false
-                            }
-                        }
-
                         AppSettingsScreen.Event.ValidateToken -> {
                             scope.launch {
                                 focusManager.clearFocus()
@@ -513,23 +435,6 @@ class AppSettingsPresenter
                                             response.imageUrl,
                                             response.refreshIntervalSeconds ?: DEFAULT_REFRESH_INTERVAL_SEC,
                                         )
-
-                                    // For BYOD devices, also fetch and save the device ID
-                                    if (deviceType == TrmnlDeviceType.BYOD) {
-                                        val deviceIdResult = displayRepository.getDeviceIdFromApi(deviceConfig)
-                                        if (deviceIdResult.isSuccess) {
-                                            val deviceId = deviceIdResult.getOrNull()
-                                            if (deviceId != null) {
-                                                deviceConfigStore.saveDeviceId(deviceId)
-                                                Timber.d("Device ID saved successfully for BYOD device: $deviceId")
-                                            }
-                                        } else {
-                                            Timber.w(
-                                                "Failed to fetch device ID for BYOD device. Error: %s",
-                                                deviceIdResult.exceptionOrNull(),
-                                            )
-                                        }
-                                    }
                                 } else {
                                     // No error but also no image URL
                                     val errorMessage = response.error ?: ""
@@ -552,14 +457,6 @@ class AppSettingsPresenter
                                             TrmnlDeviceType.TRMNL -> false
                                         }
 
-                                    // For BYOD devices, retrieve the device ID that was fetched during validation
-                                    val deviceId =
-                                        if (deviceType == TrmnlDeviceType.BYOD) {
-                                            deviceConfigStore.getDeviceId()
-                                        } else {
-                                            null
-                                        }
-
                                     deviceConfigStore.saveDeviceConfig(
                                         TrmnlDeviceConfig(
                                             type = deviceType,
@@ -569,13 +466,6 @@ class AppSettingsPresenter
                                             // Normalize the MAC address to standard format if provided in different format
                                             deviceMacId = normalizeMacAddress(deviceMacId)?.ifBlank { null },
                                             isMasterDevice = isMaster,
-                                            // Save user API token if provided (for BYOD).
-                                            // Note: user token validation is optional and may be skipped by the user.
-                                            // We still persist the token here; any invalid or expired token will be
-                                            // detected and surfaced via downstream API error handling.
-                                            userApiToken = userApiToken.ifBlank { null },
-                                            // Include device ID for BYOD devices (fetched during validation)
-                                            deviceId = deviceId,
                                         ),
                                     )
                                     trmnlWorkScheduler.updateRefreshInterval(result.refreshRateSecs)
@@ -813,104 +703,6 @@ fun AppSettingsContent(
                 deviceIdError = (state.validationResult as? ValidationResult.InvalidDeviceMacId)?.message,
             )
 
-            // User API Token field (only for BYOD)
-            AnimatedVisibility(
-                visible = state.deviceType == TrmnlDeviceType.BYOD,
-                enter = expandVertically() + fadeIn(),
-                exit = shrinkVertically() + fadeOut(),
-            ) {
-                Column {
-                    Spacer(modifier = Modifier.height(16.dp))
-
-                    var userTokenVisible by remember { mutableStateOf(false) }
-
-                    OutlinedTextField(
-                        value = state.userApiToken,
-                        onValueChange = { state.eventSink(AppSettingsScreen.Event.UserApiTokenChanged(it)) },
-                        label = { Text("User API Token (Account Key)") },
-                        modifier = Modifier.fillMaxWidth(),
-                        singleLine = true,
-                        visualTransformation = if (userTokenVisible) VisualTransformation.None else PasswordVisualTransformation(),
-                        keyboardOptions =
-                            KeyboardOptions(
-                                keyboardType = KeyboardType.Password,
-                                imeAction = ImeAction.Done,
-                            ),
-                        keyboardActions =
-                            KeyboardActions(
-                                onDone = {
-                                    state.eventSink(AppSettingsScreen.Event.ValidateUserToken)
-                                },
-                            ),
-                        supportingText = {
-                            Text(
-                                "Optional: This token is needed for device management features like battery reporting. Get this from your TRMNL user account settings.",
-                            )
-                        },
-                        trailingIcon = {
-                            IconButton(onClick = { userTokenVisible = !userTokenVisible }) {
-                                Icon(
-                                    painter =
-                                        painterResource(
-                                            if (userTokenVisible) R.drawable.visibility_off_24dp else R.drawable.visibility_24dp,
-                                        ),
-                                    contentDescription = if (userTokenVisible) "Hide user token" else "Show user token",
-                                )
-                            }
-                        },
-                        isError = state.validationResult is ValidationResult.InvalidUserToken,
-                    )
-
-                    Spacer(modifier = Modifier.height(8.dp))
-
-                    // Determine button state based on validation result
-                    val isValidationSuccess = state.validationResult is ValidationResult.UserTokenSuccess
-                    val isValidationError = state.validationResult is ValidationResult.InvalidUserToken
-
-                    Button(
-                        onClick = { state.eventSink(AppSettingsScreen.Event.ValidateUserToken) },
-                        enabled = state.userApiToken.isNotBlank() && !state.isLoading,
-                        modifier = Modifier.fillMaxWidth(),
-                        colors =
-                            when {
-                                isValidationSuccess ->
-                                    ButtonDefaults.buttonColors(
-                                        containerColor = MaterialTheme.colorScheme.primaryContainer,
-                                        contentColor = MaterialTheme.colorScheme.onPrimaryContainer,
-                                    )
-                                isValidationError ->
-                                    ButtonDefaults.buttonColors(
-                                        containerColor = MaterialTheme.colorScheme.errorContainer,
-                                        contentColor = MaterialTheme.colorScheme.onErrorContainer,
-                                    )
-                                else -> ButtonDefaults.buttonColors()
-                            },
-                    ) {
-                        Text("Validate User Token")
-                        when {
-                            isValidationSuccess -> {
-                                Spacer(modifier = Modifier.width(8.dp))
-                                Icon(
-                                    painter = painterResource(R.drawable.check_circle_24dp),
-                                    contentDescription = "Validation successful",
-                                    modifier = Modifier.size(20.dp),
-                                )
-                            }
-                            isValidationError -> {
-                                Spacer(modifier = Modifier.width(8.dp))
-                                Icon(
-                                    painter = painterResource(R.drawable.error_24dp),
-                                    contentDescription = "Validation failed",
-                                    modifier = Modifier.size(20.dp),
-                                )
-                            }
-                        }
-                    }
-                }
-            }
-
-            Spacer(modifier = Modifier.height(16.dp))
-
             // Password field with toggle visibility button
             OutlinedTextField(
                 value = state.accessToken,
@@ -1534,7 +1326,6 @@ private fun PreviewAppSettingsContentInitial() {
                     accessToken = "",
                     deviceMacId = "aa:bb:cc:dd:ee:ff",
                     isByodMasterDevice = true,
-                    userApiToken = "",
                     usesFakeApiData = true,
                     isLoading = false,
                     validationResult = null,
@@ -1557,7 +1348,6 @@ private fun PreviewAppSettingsContentLoading() {
                     accessToken = "some-token",
                     deviceMacId = "aa:bb:cc:dd:ee:ff",
                     isByodMasterDevice = true,
-                    userApiToken = "",
                     usesFakeApiData = false,
                     isLoading = true,
                     validationResult = null,
@@ -1580,7 +1370,6 @@ private fun PreviewAppSettingsContentSuccess() {
                     accessToken = "valid-token-123",
                     deviceMacId = "aa:bb:cc:dd:ee:ff",
                     isByodMasterDevice = true,
-                    userApiToken = "",
                     usesFakeApiData = false,
                     isLoading = false,
                     validationResult =
@@ -1607,7 +1396,6 @@ private fun PreviewAppSettingsContentFailure() {
                     accessToken = "invalid-token",
                     deviceMacId = "aa:bb:cc:dd:ee:ff",
                     isByodMasterDevice = true,
-                    userApiToken = "",
                     usesFakeApiData = false,
                     isLoading = false,
                     validationResult =
@@ -1637,7 +1425,6 @@ private fun PreviewAppSettingsContentWithWork() {
                     accessToken = "valid-token-123",
                     deviceMacId = "aa:bb:cc:dd:ee:ff",
                     isByodMasterDevice = true,
-                    userApiToken = "",
                     usesFakeApiData = false,
                     isLoading = false,
                     validationResult = null, // Can also be Success state
@@ -1670,7 +1457,6 @@ private fun PreviewWorkScheduleStatusCardScheduled() {
                     accessToken = "some-token",
                     deviceMacId = "AA:BB:CC:DD:EE:FF",
                     isByodMasterDevice = true,
-                    userApiToken = "",
                     usesFakeApiData = false,
                     nextRefreshJobInfo =
                         NextImageRefreshDisplayInfo(
@@ -1697,7 +1483,6 @@ private fun PreviewWorkScheduleStatusCardNoWork() {
                     accessToken = "some-token",
                     deviceMacId = "aa:bb:cc:dd:ee:ff",
                     isByodMasterDevice = true,
-                    userApiToken = "",
                     usesFakeApiData = false,
                     nextRefreshJobInfo = null,
                     eventSink = {},
@@ -1726,7 +1511,6 @@ private fun PreviewAppSettingsContentByod() {
                     accessToken = "byod-access-token-here",
                     deviceMacId = "",
                     isByodMasterDevice = false,
-                    userApiToken = "user_test123",
                     usesFakeApiData = false,
                     isLoading = false,
                     validationResult = null,
@@ -1750,7 +1534,6 @@ private fun PreviewAppSettingsContentByos() {
                     accessToken = "byos-access-token-here",
                     deviceMacId = "AA:BB:CC:DD:EE:FF",
                     isByodMasterDevice = true,
-                    userApiToken = "",
                     usesFakeApiData = false,
                     isLoading = false,
                     validationResult = null,
diff --git a/app/src/main/java/ink/trmnl/android/ui/settings/DeviceTypeInfoTexts.kt b/app/src/main/java/ink/trmnl/android/ui/settings/DeviceTypeInfoTexts.kt
index c91adbd..9da7985 100644
--- a/app/src/main/java/ink/trmnl/android/ui/settings/DeviceTypeInfoTexts.kt
+++ b/app/src/main/java/ink/trmnl/android/ui/settings/DeviceTypeInfoTexts.kt
@@ -151,7 +151,7 @@ internal fun ByosDeviceTypeInfoText() {
     val linkStyle = SpanStyle(color = MaterialTheme.colorScheme.primary, textDecoration = TextDecoration.Underline)
     val annotatedString =
         buildAnnotatedString {
-            append("Bring your own server (BYOS) config. Only secure HTTPS URL supported. ")
+            append("Bring your own server (BYOS) config.")
 
             withLink(
                 LinkAnnotation.Url(
diff --git a/app/src/main/java/ink/trmnl/android/work/TrmnlImageRefreshWorker.kt b/app/src/main/java/ink/trmnl/android/work/TrmnlImageRefreshWorker.kt
index df1d4a2..09460a4 100644
--- a/app/src/main/java/ink/trmnl/android/work/TrmnlImageRefreshWorker.kt
+++ b/app/src/main/java/ink/trmnl/android/work/TrmnlImageRefreshWorker.kt
@@ -170,8 +170,9 @@ class TrmnlImageRefreshWorker(
             httpResponseMetadata = trmnlDisplayInfo.httpResponseMetadata,
         )
 
-        // Report battery status for BYOD devices after successful image refresh
-        displayRepository.reportDeviceBatteryStatus(deviceConfig)
+        // DEPRECATED: Battery reporting now happens via Percent-Charged header in /api/display call
+        // Battery percentage is automatically sent when fetching the next image for BYOD devices
+        // displayRepository.reportDeviceBatteryStatus(deviceConfig)
 
         // NOTE: Image metadata caching is handled automatically by `TrmnlDisplayRepository`
         // when the API call succeeds, so we don't need to save it again here.
diff --git a/app/src/test/java/ink/trmnl/android/data/TrmnlDeviceConfigDataStoreTest.kt b/app/src/test/java/ink/trmnl/android/data/TrmnlDeviceConfigDataStoreTest.kt
index 95a9a33..672c99f 100644
--- a/app/src/test/java/ink/trmnl/android/data/TrmnlDeviceConfigDataStoreTest.kt
+++ b/app/src/test/java/ink/trmnl/android/data/TrmnlDeviceConfigDataStoreTest.kt
@@ -626,100 +626,4 @@ class TrmnlDeviceConfigDataStoreTest {
             val preferences = deviceConfigDataStore.deviceModelPreferencesFlow.first()
             assertThat(preferences).isEmpty()
         }
-
-    @Test
-    fun `saveDeviceId and getDeviceId work correctly`() =
-        runTest {
-            // Arrange
-            val expectedDeviceId = 12345
-
-            // Act
-            deviceConfigDataStore.saveDeviceId(expectedDeviceId)
-            val retrievedDeviceId = deviceConfigDataStore.getDeviceId()
-
-            // Assert
-            assertThat(retrievedDeviceId).isEqualTo(expectedDeviceId)
-        }
-
-    @Test
-    fun `getDeviceId returns null when not saved`() =
-        runTest {
-            // Act
-            val deviceId = deviceConfigDataStore.getDeviceId()
-
-            // Assert
-            assertThat(deviceId).isNull()
-        }
-
-    @Test
-    fun `saveDeviceConfig persists deviceId to both JSON and legacy storage`() =
-        runTest {
-            // Arrange
-            val configWithDeviceId =
-                TrmnlDeviceConfig(
-                    type = TrmnlDeviceType.BYOD,
-                    apiAccessToken = "test-token",
-                    apiBaseUrl = "https://trmnl.com",
-                    userApiToken = "user_test_token",
-                    deviceId = 999,
-                )
-
-            // Act
-            deviceConfigDataStore.saveDeviceConfig(configWithDeviceId)
-
-            // Assert - Verify device ID is persisted via getDeviceId (legacy storage)
-            val deviceId = deviceConfigDataStore.getDeviceId()
-            assertThat(deviceId).isEqualTo(999)
-
-            // Assert - Verify device ID is persisted via deviceConfigFlow (JSON storage)
-            val loadedConfig = deviceConfigDataStore.deviceConfigFlow.first()
-            assertThat(loadedConfig).isNotNull()
-            assertThat(loadedConfig?.deviceId).isEqualTo(999)
-        }
-
-    @Test
-    fun `deviceConfigFlow loads deviceId from legacy storage when JSON not present`() =
-        runTest {
-            // Arrange - Save individual fields (legacy approach) without JSON
-            deviceConfigDataStore.saveDeviceType(TrmnlDeviceType.BYOD)
-            deviceConfigDataStore.saveAccessToken("test-token")
-            deviceConfigDataStore.saveServerUrl("https://trmnl.com")
-            deviceConfigDataStore.saveDeviceId(777)
-
-            // Act
-            val loadedConfig = deviceConfigDataStore.deviceConfigFlow.first()
-
-            // Assert
-            assertThat(loadedConfig).isNotNull()
-            assertThat(loadedConfig?.deviceId).isEqualTo(777)
-            assertThat(loadedConfig?.type).isEqualTo(TrmnlDeviceType.BYOD)
-        }
-
-    @Test
-    fun `saveDeviceConfig removes deviceId from storage when null`() =
-        runTest {
-            // Arrange - First save config with deviceId
-            val configWithDeviceId =
-                TrmnlDeviceConfig(
-                    type = TrmnlDeviceType.BYOD,
-                    apiAccessToken = "test-token",
-                    apiBaseUrl = "https://trmnl.com",
-                    deviceId = 123,
-                )
-            deviceConfigDataStore.saveDeviceConfig(configWithDeviceId)
-
-            // Verify it was saved
-            assertThat(deviceConfigDataStore.getDeviceId()).isEqualTo(123)
-
-            // Act - Now save config without deviceId
-            val configWithoutDeviceId = configWithDeviceId.copy(deviceId = null)
-            deviceConfigDataStore.saveDeviceConfig(configWithoutDeviceId)
-
-            // Assert - DeviceId should be removed
-            val deviceId = deviceConfigDataStore.getDeviceId()
-            assertThat(deviceId).isNull()
-
-            val loadedConfig = deviceConfigDataStore.deviceConfigFlow.first()
-            assertThat(loadedConfig?.deviceId).isNull()
-        }
 }
diff --git a/app/src/test/java/ink/trmnl/android/data/TrmnlDisplayRepositoryTest.kt b/app/src/test/java/ink/trmnl/android/data/TrmnlDisplayRepositoryTest.kt
index 1080dde..1310e70 100644
--- a/app/src/test/java/ink/trmnl/android/data/TrmnlDisplayRepositoryTest.kt
+++ b/app/src/test/java/ink/trmnl/android/data/TrmnlDisplayRepositoryTest.kt
@@ -21,6 +21,7 @@ import okhttp3.Request
 import okhttp3.Response
 import org.junit.After
 import org.junit.Before
+import org.junit.Ignore
 import org.junit.Test
 
 /**
@@ -410,6 +411,8 @@ class TrmnlDisplayRepositoryTest {
                     accessToken = byodDeviceConfig.apiAccessToken,
                     useBase64 = any(),
                     rssi = any(),
+                    percentCharged = any(),
+                    deviceMacId = any(),
                 )
             } returns ApiResult.success(successResponse)
 
@@ -426,8 +429,10 @@ class TrmnlDisplayRepositoryTest {
                 apiService.getNextDisplayData(
                     fullApiUrl = expectedNextApiUrl,
                     accessToken = byodDeviceConfig.apiAccessToken,
+                    deviceMacId = any(),
                     useBase64 = any(),
                     rssi = any(),
+                    percentCharged = any(),
                 )
             }
         }
@@ -579,6 +584,9 @@ class TrmnlDisplayRepositoryTest {
             assertThat(result.httpResponseMetadata?.contentLength).isEqualTo(123L)
         }
 
+    // DEPRECATED: Device ID fetching is no longer needed for battery reporting
+    // Battery is now sent via Percent-Charged header
+    @Ignore("Device ID fetching deprecated - battery now uses Percent-Charged header")
     @Test
     fun `getDeviceIdFromApi should return mocked device ID`() =
         runTest {
@@ -593,15 +601,14 @@ class TrmnlDisplayRepositoryTest {
             coVerify(exactly = 0) { apiService.getDeviceMe(any(), any()) }
         }
 
+    // DEPRECATED: Battery reporting via separate API call is no longer used
+    // Battery is now sent via Percent-Charged header in /api/display call
+    @Ignore("Battery reporting via PATCH /api/devices/{id} deprecated - now uses Percent-Charged header")
     @Test
     fun `reportDeviceBatteryStatus should report battery for valid BYOD config`() =
         runTest {
             // Arrange
-            val byodConfigWithDeviceId =
-                byodDeviceConfig.copy(
-                    deviceId = 123,
-                    userApiToken = "user_test_token",
-                )
+            val byodConfigWithDeviceId = byodDeviceConfig
 
             every { androidDeviceInfoProvider.getBatteryLevel() } returns 75
 
@@ -623,20 +630,18 @@ class TrmnlDisplayRepositoryTest {
                 userApiService.updateDevice(
                     fullApiUrl = expectedApiUrl,
                     accessToken = "Bearer user_test_token",
-                    updateRequest = match { it.percentCharged == 75.0 },
+                    updateRequest = match { it.percentCharged == 75 },
                 )
             }
         }
 
+    // DEPRECATED: Battery reporting via separate API call is no longer used
+    @Ignore("Battery reporting via PATCH /api/devices/{id} deprecated - now uses Percent-Charged header")
     @Test
     fun `reportDeviceBatteryStatus should skip for non-BYOD device`() =
         runTest {
             // Arrange - TRMNL device (not BYOD)
-            val trmnlConfig =
-                testDeviceConfig.copy(
-                    deviceId = 123,
-                    userApiToken = "user_test_token",
-                )
+            val trmnlConfig = testDeviceConfig
 
             // Act
             repository.reportDeviceBatteryStatus(trmnlConfig)
@@ -646,15 +651,13 @@ class TrmnlDisplayRepositoryTest {
             coVerify(exactly = 0) { androidDeviceInfoProvider.getBatteryLevel() }
         }
 
+    // DEPRECATED: Battery reporting via separate API call is no longer used
+    @Ignore("Battery reporting via PATCH /api/devices/{id} deprecated - now uses Percent-Charged header")
     @Test
     fun `reportDeviceBatteryStatus should skip when deviceId is null`() =
         runTest {
             // Arrange
-            val configWithoutDeviceId =
-                byodDeviceConfig.copy(
-                    deviceId = null,
-                    userApiToken = "user_test_token",
-                )
+            val configWithoutDeviceId = byodDeviceConfig
 
             // Act
             repository.reportDeviceBatteryStatus(configWithoutDeviceId)
@@ -664,15 +667,13 @@ class TrmnlDisplayRepositoryTest {
             coVerify(exactly = 0) { androidDeviceInfoProvider.getBatteryLevel() }
         }
 
+    // DEPRECATED: Battery reporting via separate API call is no longer used
+    @Ignore("Battery reporting via PATCH /api/devices/{id} deprecated - now uses Percent-Charged header")
     @Test
     fun `reportDeviceBatteryStatus should skip when userApiToken is null`() =
         runTest {
             // Arrange
-            val configWithoutUserToken =
-                byodDeviceConfig.copy(
-                    deviceId = 123,
-                    userApiToken = null,
-                )
+            val configWithoutUserToken = byodDeviceConfig
 
             // Act
             repository.reportDeviceBatteryStatus(configWithoutUserToken)
@@ -682,15 +683,13 @@ class TrmnlDisplayRepositoryTest {
             coVerify(exactly = 0) { androidDeviceInfoProvider.getBatteryLevel() }
         }
 
+    // DEPRECATED: Battery reporting via separate API call is no longer used
+    @Ignore("Battery reporting via PATCH /api/devices/{id} deprecated - now uses Percent-Charged header")
     @Test
     fun `reportDeviceBatteryStatus should skip when battery level unavailable`() =
         runTest {
             // Arrange
-            val byodConfigWithDeviceId =
-                byodDeviceConfig.copy(
-                    deviceId = 123,
-                    userApiToken = "user_test_token",
-                )
+            val byodConfigWithDeviceId = byodDeviceConfig
 
             every { androidDeviceInfoProvider.getBatteryLevel() } returns null
 
@@ -710,13 +709,13 @@ class TrmnlDisplayRepositoryTest {
             // Arrange
             val byodConfig =
                 byodDeviceConfig.copy(
-                    deviceId = null,
-                    userApiToken = "test_token",
                     apiAccessToken = "test_api_key",
                 )
             val expectedRssi = -65
+            val expectedBattery = 80
 
             every { androidDeviceInfoProvider.getWifiSignalStrength() } returns expectedRssi
+            every { androidDeviceInfoProvider.getBatteryLevel() } returns expectedBattery
 
             coEvery {
                 apiService.getNextDisplayData(
@@ -725,6 +724,7 @@ class TrmnlDisplayRepositoryTest {
                     deviceMacId = any(),
                     useBase64 = any(),
                     rssi = expectedRssi,
+                    percentCharged = expectedBattery,
                 )
             } returns ApiResult.success(mockk(relaxed = true))
 
@@ -740,6 +740,7 @@ class TrmnlDisplayRepositoryTest {
                     deviceMacId = any(),
                     useBase64 = any(),
                     rssi = expectedRssi,
+                    percentCharged = expectedBattery,
                 )
             }
         }
@@ -750,14 +751,14 @@ class TrmnlDisplayRepositoryTest {
             // Arrange
             val byodConfig =
                 byodDeviceConfig.copy(
-                    deviceId = null,
-                    userApiToken = "test_token",
                     apiAccessToken = "test_api_key",
                 )
+            val expectedBattery = 80
 
             every { androidDeviceInfoProvider.getWifiSignalStrength() } returns null
+            every { androidDeviceInfoProvider.getBatteryLevel() } returns expectedBattery
 
-            coEvery { apiService.getNextDisplayData(any(), any(), any(), any()) } returns
+            coEvery { apiService.getNextDisplayData(any(), any(), any(), any(), any(), any()) } returns
                 ApiResult.success(mockk(relaxed = true))
 
             // Act
@@ -772,6 +773,7 @@ class TrmnlDisplayRepositoryTest {
                     deviceMacId = any(),
                     useBase64 = any(),
                     rssi = null,
+                    percentCharged = expectedBattery,
                 )
             }
         }
@@ -785,7 +787,7 @@ class TrmnlDisplayRepositoryTest {
                     apiAccessToken = "trmnl_api_key",
                 )
 
-            coEvery { apiService.getNextDisplayData(any(), any(), any(), any()) } returns
+            coEvery { apiService.getNextDisplayData(any(), any(), any(), any(), any(), any()) } returns
                 ApiResult.success(mockk(relaxed = true))
 
             // Act
@@ -800,6 +802,7 @@ class TrmnlDisplayRepositoryTest {
                     deviceMacId = any(),
                     useBase64 = any(),
                     rssi = null,
+                    percentCharged = null,
                 )
             }
         }
@@ -833,6 +836,164 @@ class TrmnlDisplayRepositoryTest {
             }
         }
 
+    // Battery Percentage (Percent-Charged Header) Tests
+
+    @Test
+    fun `getNextDisplayData should send battery percentage for BYOD device when available`() =
+        runTest {
+            // Arrange
+            val byodConfig =
+                byodDeviceConfig.copy(
+                    apiAccessToken = "test_api_key",
+                )
+            val expectedBatteryLevel = 75
+
+            every { androidDeviceInfoProvider.getBatteryLevel() } returns expectedBatteryLevel
+            every { androidDeviceInfoProvider.getWifiSignalStrength() } returns -65
+
+            coEvery {
+                apiService.getNextDisplayData(
+                    fullApiUrl = any(),
+                    accessToken = any(),
+                    deviceMacId = any(),
+                    useBase64 = any(),
+                    rssi = any(),
+                    percentCharged = 75,
+                )
+            } returns ApiResult.success(mockk(relaxed = true))
+
+            // Act
+            repository.getNextDisplayData(byodConfig)
+
+            // Assert - Verify battery level was fetched and sent as header
+            coVerify(exactly = 1) { androidDeviceInfoProvider.getBatteryLevel() }
+            coVerify {
+                apiService.getNextDisplayData(
+                    fullApiUrl = any(),
+                    accessToken = any(),
+                    deviceMacId = any(),
+                    useBase64 = any(),
+                    rssi = any(),
+                    percentCharged = 75,
+                )
+            }
+        }
+
+    @Test
+    fun `getNextDisplayData should send null battery percentage for BYOD when unavailable`() =
+        runTest {
+            // Arrange
+            val byodConfig =
+                byodDeviceConfig.copy(
+                    apiAccessToken = "test_api_key",
+                )
+
+            every { androidDeviceInfoProvider.getBatteryLevel() } returns null
+            every { androidDeviceInfoProvider.getWifiSignalStrength() } returns -65
+
+            coEvery {
+                apiService.getNextDisplayData(
+                    fullApiUrl = any(),
+                    accessToken = any(),
+                    deviceMacId = any(),
+                    useBase64 = any(),
+                    rssi = any(),
+                    percentCharged = null,
+                )
+            } returns ApiResult.success(mockk(relaxed = true))
+
+            // Act
+            repository.getNextDisplayData(byodConfig)
+
+            // Assert - Verify battery level was fetched but null was sent
+            coVerify(exactly = 1) { androidDeviceInfoProvider.getBatteryLevel() }
+            coVerify {
+                apiService.getNextDisplayData(
+                    fullApiUrl = any(),
+                    accessToken = any(),
+                    deviceMacId = any(),
+                    useBase64 = any(),
+                    rssi = any(),
+                    percentCharged = null,
+                )
+            }
+        }
+
+    @Test
+    fun `getNextDisplayData should NOT send battery percentage for TRMNL device`() =
+        runTest {
+            // Arrange - TRMNL device (not BYOD)
+            val trmnlConfig =
+                testDeviceConfig.copy(
+                    apiAccessToken = "trmnl_api_key",
+                )
+
+            coEvery {
+                apiService.getNextDisplayData(
+                    fullApiUrl = any(),
+                    accessToken = any(),
+                    deviceMacId = any(),
+                    useBase64 = any(),
+                    rssi = null,
+                    percentCharged = null,
+                )
+            } returns ApiResult.success(mockk(relaxed = true))
+
+            // Act
+            repository.getNextDisplayData(trmnlConfig)
+
+            // Assert - Verify battery level was NOT fetched and null was sent
+            coVerify(exactly = 0) { androidDeviceInfoProvider.getBatteryLevel() }
+            coVerify {
+                apiService.getNextDisplayData(
+                    fullApiUrl = any(),
+                    accessToken = any(),
+                    deviceMacId = any(),
+                    useBase64 = any(),
+                    rssi = null,
+                    percentCharged = null,
+                )
+            }
+        }
+
+    @Test
+    fun `getNextDisplayData should NOT send battery percentage for BYOS device`() =
+        runTest {
+            // Arrange - BYOS device
+            val byosConfig =
+                byosDeviceConfig.copy(
+                    apiAccessToken = "byos_api_key",
+                )
+
+            coEvery {
+                apiService.getNextDisplayData(
+                    fullApiUrl = any(),
+                    accessToken = any(),
+                    deviceMacId = any(),
+                    useBase64 = any(),
+                    rssi = null,
+                    percentCharged = null,
+                )
+            } returns ApiResult.success(mockk(relaxed = true))
+
+            // Act
+            repository.getNextDisplayData(byosConfig)
+
+            // Assert - Verify battery level was NOT fetched for BYOS device
+            coVerify(exactly = 0) { androidDeviceInfoProvider.getBatteryLevel() }
+            // Verify null battery percentage was sent
+            coVerify {
+                apiService.getNextDisplayData(
+                    fullApiUrl = any(),
+                    accessToken = any(),
+                    deviceMacId = any(),
+                    useBase64 = any(),
+                    rssi = null,
+                    percentCharged = null,
+                )
+            }
+        }
+
     @Test
     fun `getNextDisplayData should call getWifiSignalStrength only for BYOD devices`() =
         runTest {
@@ -842,8 +1003,9 @@ class TrmnlDisplayRepositoryTest {
             val byosConfig = byosDeviceConfig.copy(apiAccessToken = "byos_key")
 
             every { androidDeviceInfoProvider.getWifiSignalStrength() } returns -70
+            every { androidDeviceInfoProvider.getBatteryLevel() } returns 75
 
-            coEvery { apiService.getNextDisplayData(any(), any(), any(), any(), any()) } returns
+            coEvery { apiService.getNextDisplayData(any(), any(), any(), any(), any(), any()) } returns
                 ApiResult.success(mockk(relaxed = true))
 
             // Act - Fetch for all device types
@@ -861,8 +1023,10 @@ class TrmnlDisplayRepositoryTest {
             // Arrange
             val byodConfig = byodDeviceConfig.copy(apiAccessToken = "test_key")
             val strongSignal = -30 // Excellent signal
+            val expectedBattery = 80
 
             every { androidDeviceInfoProvider.getWifiSignalStrength() } returns strongSignal
+            every { androidDeviceInfoProvider.getBatteryLevel() } returns expectedBattery
 
             coEvery {
                 apiService.getNextDisplayData(
@@ -871,6 +1035,7 @@ class TrmnlDisplayRepositoryTest {
                     deviceMacId = any(),
                     useBase64 = any(),
                     rssi = strongSignal,
+                    percentCharged = expectedBattery,
                 )
             } returns ApiResult.success(mockk(relaxed = true))
 
@@ -885,6 +1050,7 @@ class TrmnlDisplayRepositoryTest {
                     deviceMacId = any(),
                     useBase64 = any(),
                     rssi = strongSignal,
+                    percentCharged = expectedBattery,
                 )
             }
         }
@@ -895,8 +1061,10 @@ class TrmnlDisplayRepositoryTest {
             // Arrange
             val byodConfig = byodDeviceConfig.copy(apiAccessToken = "test_key")
             val weakSignal = -90 // Very weak signal
+            val expectedBattery = 80
 
             every { androidDeviceInfoProvider.getWifiSignalStrength() } returns weakSignal
+            every { androidDeviceInfoProvider.getBatteryLevel() } returns expectedBattery
 
             coEvery {
                 apiService.getNextDisplayData(
@@ -905,6 +1073,7 @@ class TrmnlDisplayRepositoryTest {
                     deviceMacId = any(),
                     useBase64 = any(),
                     rssi = weakSignal,
+                    percentCharged = expectedBattery,
                 )
             } returns ApiResult.success(mockk(relaxed = true))
 
@@ -919,6 +1088,7 @@ class TrmnlDisplayRepositoryTest {
                     deviceMacId = any(),
                     useBase64 = any(),
                     rssi = weakSignal,
+                    percentCharged = expectedBattery,
                 )
             }
         }
diff --git a/project-resources/trmnl-api/trmnl-openapi.yaml b/project-resources/trmnl-api/trmnl-openapi.yaml
index df7436d..553e41f 100644
--- a/project-resources/trmnl-api/trmnl-openapi.yaml
+++ b/project-resources/trmnl-api/trmnl-openapi.yaml
@@ -22,6 +22,12 @@ paths:
         description: Device battery voltage (eg. 3.7)
         schema:
           type: number
+      - name: Percent-Charged
+        in: header
+        required: false
+        description: Device percent charged (eg. 69.4)
+        schema:
+          type: number
       - name: FW-Version
         in: header
         required: false