Android : Do something when battery is at a defined level

android, android-intent, power-management

Solution

`ACTION_BATTERY_LOW` doesn't have the Extras you're trying to read from it, so you're getting `percent` as `-1` every time.

As @bimal hinted at, those Extras are attached to the `ACTION_BATTERY_CHANGED` Broadcast. That doesn't mean, however, that you should just register to receive that instead. `ACTION_BATTERY_CHANGED` is sticky, so `registerReceiver()` returns the last Intent immediately. That means you can do something like:

public void onReceive(Context context, Intent intent) {
    if(intent.getAction().equals(ACTION_BATTERY_LOW)) {
        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, 100);
        int percent = (level*100)/scale; 

        if (percent <= 10 && percent > 5) {
            // Do Something
        }
    }
}

Note that `registerReciever()` was called with a `null` BroadcastReceiver, so you don't have to worry about unregistering. This is a nice, clean way to just say "What is the battery status right now?" (Well, technically, it's what was it last time a Broadcast was sent.)

Problem

I'm stuck with a little problem here. I want my app to do something, but only when the battery is at 10%. My app doesn't watch the battery level constantly; it just waits for a LOW_BATTERY intent. It works if i don't specify a level, but it works 3 times: 15%, 10%, and 5% I only want it to do something at 10%. Here is my code : ``` public void onReceive(Context context, Intent intent) { if(intent.getAction().equals(ACTION_BATTERY_LOW)) { int level = intent.getIntExtra(BatteryManager.EXTRA_LEVEL, -1); int scale = intent.getIntExtra(BatteryManager.EXTRA_SCALE, 100); int percent = (level*100)/scale; if(percent == 10) { // Do Something } } } ```

Original source