This one seems to be a most popular battery widget.
Here the first and default template:
Classic look, you can see battery percentage in status bar, notification area and battery widget of your device.
This small app helps you monitor your battery life so you can easily see how many hours remain. Once you install the app, all you need to do is to select one of the cool and unique battery template that are available and add the battery widget to your home screen. The battery information will then be displayed in the status bar, notification area and battery widget of your device.
✓ Classic battery
✓ Beer mug
✓ Orange battery
✓ Futuristic battery saver
✓ Green power widget
✓ Cute kitten
✓ Radiation hazard battery
✓ Bio hazard battery
✓ Alien power battery
✓ Love battery widget
All templates are designed by Red Dodo
✓ Shows battery percent, temperature and voltage information.
✓ Power source indicator.
✓ Hi-quality widget in 2 sizes.
✓ Can be used as a battery saver.
Free Download Battery on Google Play