TIME FOR NEW BATTERIES?
Everyone has a drawer filled with new and half-dead batteries, but how do you know which ones still have juice? Battery testers and volt meters will give you an accurate reading, but what if you don’t have one?
With a 9-volt batteries you can touch the terminals to your tongue, if you get a little shock, the battery is still good. But, the shock method doesn’t work with other batteries. For those, you can simply bounce them. Fresh alkaline batteries don’t bounce. It works on AAA, AA, C, D, and 9V batteries. The deader the battery the higher it bounces. This works because inside the batteries, zinc metal changes to zinc oxide to produce electricity. When the battery is new, the zinc metal is tightly packed, so it doesn’t bounce. Zinc oxide forms bridges that act like springs, resulting in bouncy battery. Now you won’t have to throw away perfectly good batteries ever again.