AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="org.example.battery_level_monitor_example"
    android:versionCode="1"
    android:versionName="0.0.1">

    <uses-sdk
        android:minSdkVersion="9"
        android:targetSdkVersion="16" />

    <uses-permission android:name="android.permission.INTERNET" /> 

    <application
        android:label="@string/app_name">

        <receiver android:name=".PowerConnectionReceiver">
          <intent-filter>
            <action android:name="android.intent.action.ACTION_POWER_CONNECTED"/>
            <action android:name="android.intent.action.ACTION_POWER_DISCONNECTED"/>
          </intent-filter>
        </receiver>

    </application>
</manifest>

AndroidSendBatteryLevel.scala

/*
 * INFO:
 *   http://developer.android.com/training/monitoring-device-state/battery-monitoring.html
 */

import android.content.{BroadcastReceiver, Context, Intent}
import android.os.BatteryManager

import org.apache.http.HttpResponse
import org.apache.http.client.methods.HttpPost
import org.apache.http.entity.{StringEntity, ByteArrayEntity}
import org.apache.http.impl.client.DefaultHttpClient
import org.apache.http.params.{HttpConnectionParams, BasicHttpParams}

  
class PowerConnectionReceiver extends BroadcastReceiver {
  val TARGET_URL = "http://example.org/targetScript"
  
  override def onReceive(context: Context, intent: Intent) {
    val json = createJSON(intent)
    execPostRequest(TARGET_URL, json)
  }

  def createJSON(intent: Intent): String = {
    // Extract info from intent
    val status = intent.getIntExtra(BatteryManager.EXTRA_STATUS, -1)
    val chargePlug = intent.getIntExtra(BatteryManager.EXTRA_PLUGGED, -1)
    val batteryLevel = intent.getIntExtra(BatteryManager.EXTRA_LEVEL, -1)
    val batteryScale = intent.getIntExtra(BatteryManager.EXTRA_SCALE, -1)
    val batteryPercent = batteryLevel / batteryScale.toFloat

    val isCharging = status == BatteryManager.BATTERY_STATUS_CHARGING || status == BatteryManager.BATTERY_STATUS_FULL
    val isChargingViaUSB = chargePlug == BatteryManager.BATTERY_PLUGGED_USB
    val isChargingViaACCharger = chargePlug == BatteryManager.BATTERY_PLUGGED_AC

    // Create and return JSON object as string
    ???
  }
    
  def execPostRequest(uri: String, message: String, timeout: Int = 30000): HttpResponse = {
    val httpParams = new BasicHttpParams
    HttpConnectionParams.setSoTimeout(httpParams, timeout)
    val client = new DefaultHttpClient(httpParams)
    val request = new HttpPost(uri)
    request.setEntity(new StringEntity(message))
    client.execute(request)
  }

}