BatteryStatusHelper.java

package org.bookdash.android;

import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.BatteryManager;


public class BatteryStatusHelper {

    private final Context context;

    public BatteryStatusHelper(Context context) {
        this.context = context;
    }

    public int getBatteryPercentage() {
        IntentFilter ifilter = new IntentFilter(Intent.ACTION_BATTERY_CHANGED);
        Intent batteryStatus = context.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 Math.round(batteryPct * 100);
    }

}