CODEWITHSUNDEEP
androidbattery
David Given
David Given

Reputation: 13701

Polling ACTION_BATTERY_LOW

When the battery gets low, Android will send an ACTION_BATTERY_LOW intent. Then when it's okay again, it sends ACTION_BATTERY_OKAY.

Unfortunately if my application is started while the battery is low, then I don't get sent the intent; it's not sticky so I can't detect whether a battery alert is currently extant. ACTION_BATTERY_CHANGED is sticky, but it only tells me the current battery charge state, on not whether the system has declared a low battery alert or not.

Is there any way to detect whether the battery is low at any given instant?

Upvotes: 5

Views: 3170

Answers (3)

Mars Gao
Mars Gao

Reputation: 69

It's a very tricky question.The related code on Android Developer has a mistake.

Basically, you can learn how to detect it on this link:

https://developer.android.com/training/monitoring-device-state/battery-monitoring.html

You can detect whether it is charging or not charging and low battery or not by a broadcast receiver, using method OnReceive(Context context, Intent intent){}

However, there is a mistake in this link, for monitoring the significant changes.[Notice here, action name is android.intent.action.ACTION_BATTERY_LOW]

[1]

But let's see how it is described in Intent.

ACTION_BATTERY_LOW

Added in API level 1 String ACTION_BATTERY_LOW Broadcast Action: Indicates low battery condition on the device. This broadcast corresponds to the "Low battery warning" system dialog.

This is a protected intent that can only be sent by the system.

Constant Value: "android.intent.action.BATTERY_LOW" You can find this in Android Developers Intent.

In other words, a mistake happens here. It should be action.BATTERY_LOW instead of action.ACTION_BATTERY_LOW.So your code in AndroidManifest should be:

<receiver android:name=".receiver.BatteryLevelReceiver">
        <intent-filter>
            <action android:name="android.intent.action.BATTERY_LOW"/>

            <!--instead of android.intent.action.ACTION_BATTERY_LOW-->
        </intent-filter>
    </receiver>

Also make sure you have your Receiver correct.

public class BatteryLevelReceiver extends BroadcastReceiver {
@Override
public void onReceive(Context context, Intent intent) {

        Toast.makeText(context, "BAttery's dying!!", Toast.LENGTH_LONG).show();
        Log.e("", "BATTERY LOW!!");

}

}

It's diffcult to debug or get Log on your laptop, the use of Toast might help.

        Toast.makeText(context, "BAttery's dying!!", Toast.LENGTH_LONG).show();
        //Toast.makeText(Context context, String str, Integer integer).show();

Hopefully it helps to solve you problem.

Upvotes: 2

Frank Sposaro
Frank Sposaro

Reputation: 8531

The sticky intent still has some information in it. You should still be able to get the battery level

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

float batteryPct = level / (float)scale;

taken from http://developer.android.com/training/monitoring-device-state/battery-monitoring.html

Upvotes: 1

Ran
Ran

Reputation: 4157

Usually low battery warning appears at 15% , so you can check if the battery level is equal or less than 15%.

Upvotes: 1

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