He created a simple circuit that drains any AA battery, NiMh or NiCd, and records its useful capacity in milliamp hours.

If you want to get your hands dirty and build your own, Johan has embraced the spirit of Arduino fully, and made schematics and all the other fun things you need available on GitHub.

You can also go the 9v battery route plugged into the on-board regulator of the Arduino but the low mAh rating of a 9v won’t allow your project to stay running for very long.

Adafruit has announced the launch of a new product today in the form of the VERTER power converter, which has been created to convert just about any battery pack to 5V for just $9.95 VERTER is ...