La Crosse Technology 911-114 Portable Battery Tester
La Crosse couldn't have made testing your batteries any easier. This small unit (only about four inches long) can go anywhere you need to test batteries effectively and accurately. Just stick an alkaline or rechargeable AA, AAA, C, or D battery into the slot at the front and push the contacts together. Instantly, the needle reacts on the multi-colored meter at top. You can test 9-volt batteries as well, just apply one to the top of the unit instead of the front. There is one drawback to the 911-114, in that the meter is pretty small and might be hard to read for those with poor or impaired vision.