Verificando a Bateria

alternate.java

public float getBatteryLevel() {
    Intent batteryIntent = registerReceiver(null, new IntentFilter(Intent.ACTION_BATTERY_CHANGED));
    int level = batteryIntent.getIntExtra(BatteryManager.EXTRA_LEVEL, -1);
    int scale = batteryIntent.getIntExtra(BatteryManager.EXTRA_SCALE, -1);

    // Error checking that probably isn't needed but I added just in case.
    if(level == -1 || scale == -1) {
        return 50.0f;
    }

    return ((float)level / (float)scale) * 100.0f; 
}

@Override
public void onCreate() {
    BroadcastReceiver batteryReceiver = new BroadcastReceiver() {
        int scale = -1;
        int level = -1;
        int voltage = -1;
        int temp = -1;
        @Override
        public void onReceive(Context context, Intent intent) {
            level = intent.getIntExtra(BatteryManager.EXTRA_LEVEL, -1);
            scale = intent.getIntExtra(BatteryManager.EXTRA_SCALE, -1);
            temp = intent.getIntExtra(BatteryManager.EXTRA_TEMPERATURE, -1);
            voltage = intent.getIntExtra(BatteryManager.EXTRA_VOLTAGE, -1);
            Log.e("BatteryManager", "level is "+level+"/"+scale+", temp is "+temp+", voltage is "+voltage);
        }
    };
    IntentFilter filter = new IntentFilter(Intent.ACTION_BATTERY_CHANGED);
    registerReceiver(batteryReceiver, filter);
}

battery.xml

<?xml version="1.0" encoding="utf-8"?> 
<LinearLayout 
  xmlns:android="http://schemas.android.com/apk/res/android" 
  android:orientation="vertical" 
  android:layout_width="fill_parent" 
  android:layout_height="fill_parent"> 
  
    <TextView         
        android:id="@+id/batteryLevel"
        android:layout_width="fill_parent" 
        android:layout_height="fill_parent" 
        android:gravity="center_vertical|center_horizontal"
        android:textSize="50dip"> 
    </TextView>
    
</LinearLayout>

BatteryInformation

package br.com.targettrust.battery;

import android.app.Activity;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.BatteryManager;
import android.os.Bundle;
import android.widget.ImageView;
import android.widget.TextView;
 
 
public class BatteryInformation extends Activity {
	private TextView batteryInfo;
	private ImageView imageBatteryState;
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        batteryInfo=(TextView)findViewById(R.id.textViewBatteryInfo);
        imageBatteryState=(ImageView)findViewById(R.id.imageViewBatteryState);
        
        this.registerReceiver(this.batteryInfoReceiver,	new IntentFilter(Intent.ACTION_BATTERY_CHANGED));
    }
    
    private BroadcastReceiver batteryInfoReceiver = new BroadcastReceiver() {
		@Override
		public void onReceive(Context context, Intent intent) {
			
			int  health= intent.getIntExtra(BatteryManager.EXTRA_HEALTH,0);
			int  icon_small= intent.getIntExtra(BatteryManager.EXTRA_ICON_SMALL,0);
			int  level= intent.getIntExtra(BatteryManager.EXTRA_LEVEL,0);
			int  plugged= intent.getIntExtra(BatteryManager.EXTRA_PLUGGED,0);
			boolean  present= intent.getExtras().getBoolean(BatteryManager.EXTRA_PRESENT); 
			int  scale= intent.getIntExtra(BatteryManager.EXTRA_SCALE,0);
			int  status= intent.getIntExtra(BatteryManager.EXTRA_STATUS,0);
			String  technology= intent.getExtras().getString(BatteryManager.EXTRA_TECHNOLOGY);
			int  temperature= intent.getIntExtra(BatteryManager.EXTRA_TEMPERATURE,0);
			int  voltage= intent.getIntExtra(BatteryManager.EXTRA_VOLTAGE,0);
			
 
			batteryInfo.setText(
					"Health: "+health+"\n"+
					"Icon Small:"+icon_small+"\n"+
					"Level: "+level+"\n"+
					"Plugged: "+plugged+"\n"+
					"Present: "+present+"\n"+
					"Scale: "+scale+"\n"+
					"Status: "+status+"\n"+
					"Technology: "+technology+"\n"+
					"Temperature: "+temperature+"\n"+
					"Voltage: "+voltage+"\n");
			imageBatteryState.setImageResource(icon_small);
		}
	};
    
 
}

BatteryLevelActivity.java

package br.com.targettrust.battery;

import android.app.Activity;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.Bundle;
import android.widget.TextView;

public class BatteryLevelActivity extends Activity {
    private TextView batterLevel;

    @Override
    public void onCreate(Bundle icicle) {
        super.onCreate(icicle);
        setContentView(R.layout.main);
        batterLevel = (TextView) this.findViewById(R.id.batteryLevel);
        batteryLevel();
    }

    private void batteryLevel() {
        BroadcastReceiver batteryLevelReceiver = new BroadcastReceiver() {
            public void onReceive(Context context, Intent intent) {
                context.unregisterReceiver(this);
                int rawlevel = intent.getIntExtra("level", -1);
                int scale = intent.getIntExtra("scale", -1);
                int level = -1;
                if (rawlevel >= 0 && scale > 0) {
                    level = (rawlevel * 100) / scale;
                }
                batterLevel.setText("Battery Level Remaining: " + level + "%");
            }
        };
        IntentFilter batteryLevelFilter = new IntentFilter(Intent.ACTION_BATTERY_CHANGED);
        registerReceiver(batteryLevelReceiver, batteryLevelFilter);
    }
    
}