Get battery level and state in Android

Question

How can I get battery level and state (plugged in, discharging, charging, etc)? I researched the developer docs and I found a BatteryManager class. But it doesn't contain any methods, just constants. How do I even use it?

Solution 1

Here is a code sample that explains how to get battery information.

To sum it up, a broadcast receiver for the ACTION_BATTERY_CHANGED intent is set up dynamically, because it can not be received through components declared in manifests, only by explicitly registering for it with Context.registerReceiver().

public class Main extends Activity {
  private TextView batteryTxt;
  private BroadcastReceiver mBatInfoReceiver = new BroadcastReceiver(){
    @Override
    public void onReceive(Context ctxt, Intent intent) {
      int level = intent.getIntExtra(BatteryManager.EXTRA_LEVEL, -1);
      int scale = intent.getIntExtra(BatteryManager.EXTRA_SCALE, -1);
      float batteryPct = level * 100 / (float)scale;
      batteryTxt.setText(String.valueOf(batteryPct) + "%");
    }
  };

  @Override
  public void onCreate(Bundle b) {
    super.onCreate(b);
    setContentView(R.layout.main);
    batteryTxt = (TextView) this.findViewById(R.id.batteryTxt);
    this.registerReceiver(this.mBatInfoReceiver, new IntentFilter(Intent.ACTION_BATTERY_CHANGED));
  }
}

Solution 2

Since SDK 21 LOLLIPOP it is possible to use the following to get current battery level as a percentage:

BatteryManager bm = (BatteryManager) context.getSystemService(BATTERY_SERVICE);
int batLevel = bm.getIntProperty(BatteryManager.BATTERY_PROPERTY_CAPACITY);

Read BatteryManager  |  Android Developers - BATTERY_PROPERTY_CAPACITY

Solution 3

Based on official android docs, you can use this method in a Helper or Util class to get current battery percentage:

Java version:

public static int getBatteryPercentage(Context context) {

    if (Build.VERSION.SDK_INT >= 21) {

         BatteryManager bm = (BatteryManager) context.getSystemService(BATTERY_SERVICE);
         return bm.getIntProperty(BatteryManager.BATTERY_PROPERTY_CAPACITY);

    } else {

         IntentFilter iFilter = new IntentFilter(Intent.ACTION_BATTERY_CHANGED);
         Intent batteryStatus = context.registerReceiver(null, iFilter);

         int level = batteryStatus != null ? batteryStatus.getIntExtra(BatteryManager.EXTRA_LEVEL, -1) : -1;
         int scale = batteryStatus != null ? batteryStatus.getIntExtra(BatteryManager.EXTRA_SCALE, -1) : -1;

         double batteryPct = level / (double) scale;

         return (int) (batteryPct * 100);
   }
}

Kotlin version:

fun getBatteryPercentage(context: Context): Int {
    return if (Build.VERSION.SDK_INT >= 21) {
        val bm = context.getSystemService(BATTERY_SERVICE) as BatteryManager
        bm.getIntProperty(BatteryManager.BATTERY_PROPERTY_CAPACITY)
    
    } else {
        val iFilter = IntentFilter(Intent.ACTION_BATTERY_CHANGED)
        val batteryStatus: Intent = context.registerReceiver(null, iFilter)
        val level = batteryStatus?.getIntExtra(BatteryManager.EXTRA_LEVEL, -1)
        val scale = batteryStatus?.getIntExtra(BatteryManager.EXTRA_SCALE, -1)
        val batteryPct = level / scale.toDouble()
        (batteryPct * 100).toInt()
    }
}

Solution 4

You don't have to register an actual BroadcastReceiver as Android's BatteryManager is using a sticky Intent:

IntentFilter ifilter = new IntentFilter(Intent.ACTION_BATTERY_CHANGED);
Intent batteryStatus = registerReceiver(null, ifilter);

int level = batteryStatus.getIntExtra(BatteryManager.EXTRA_LEVEL, -1);
int scale = batteryStatus.getIntExtra(BatteryManager.EXTRA_SCALE, -1);

float batteryPct = level / (float)scale;

return (int)(batteryPct*100);

This is from the official docs over at https://developer.android.com/training/monitoring-device-state/battery-monitoring.html.

Solution 5

Other answers didn't mention how to access battery status (chraging or not).

IntentFilter ifilter = new IntentFilter(Intent.ACTION_BATTERY_CHANGED);
Intent batteryStatus = context.registerReceiver(null, ifilter);

// Are we charging / charged?
int status = batteryStatus.getIntExtra(BatteryManager.EXTRA_STATUS, -1);
boolean isCharging = status == BatteryManager.BATTERY_STATUS_CHARGING ||
                     status == BatteryManager.BATTERY_STATUS_FULL;

// How are we charging?
int chargePlug = batteryStatus.getIntExtra(BatteryManager.EXTRA_PLUGGED, -1);
boolean usbCharge = chargePlug == BatteryManager.BATTERY_PLUGGED_USB;
boolean acCharge = chargePlug == BatteryManager.BATTERY_PLUGGED_AC;

View more solutions

Comments

[Mohit Deshpande]

After some MORE researching, I found BatteryManager.EXTRA_LEVEL.

[class Android]

About Intent.ACTION_BATTERY_CHANGED: This is a sticky broadcast containing the charging state, level, and other information about the battery. You can not receive this through components declared in manifests, only by explicitly registering for it with Context.registerReceiver().

[SirDarius]

@classAndroid well, yes, that's explicitely stated in the answer.

[class Android]

Yes @SirDarius, just letting others know about it. I upvoted your answer first and put this comment when I found it out. :)

[Dave Doga Oz]

don't forget to unRegisterReceiver onPause or onDestroy.

[user2212515]

one mistake in official docs, you must use double instead float int level = batteryStatus != null ? batteryStatus.getIntExtra(BatteryManager.EXTRA_LEVEL, -1) : -1; int scale = batteryStatus != null ? batteryStatus.getIntExtra(BatteryManager.EXTRA_SCALE, -1) : -1; double batteryPct = (double) level / (double) scale; int percent = (int) (batteryPct * 100D);

[blueware]

@user2212515, would you mind edit my answer based on the official docs?

[Robyer]

Isn't that 0.53F -> 52F mistake caused by casting final value to int (thus stripping any decimal 0.x value from it), instead of using Math.round()?

[Pemba Tamang]

hey I used this and sometimes the result is is 89 sometimes its 00.89 its moving the decimals whats happening

[blueware]

@Ryan, I edited my answer to support android v21 and later. Please check it out.

[subhashchandru]

Cannot able to instaialise battery manager with new Keywork , Why sir ?

[Robin Hsu]

EXTRA_LEVEL is not exact. You need to scale it. See this link for detail.

[user924]

there is no state, only level, why it was accept if it's not a full answer?

[user924]

Finally, someone who answered about battery status

[SirDarius]

@user924 if you think you can improve this answer, please feel free to do so. If the Original Poster accepted this answer, I believe they were satisfied with the contents.

[user924]

from author question Get battery level and *state* in Android. Is there any code to get state in your code? no :) Check here stackoverflow.com/a/59025376/7767664

[Sambhav Khandelwal]

Dont we need any permissions for it?