If you find yourself dealing with plenty of wireless electronics on a daily basis, chances are you keep buying and discarding batteries all the time. Before doing so, you want to make sure your test your batteries. The Digital Battery Checker is a compact device that makes that possible. This tiny gadget handles AAA, AA, C, D, and 1.5V coin cells. It tells you whether the battery you have in your hands is worth keeping.
[via Book of Joe]