We recently came across this pretty slick way to test batteries…without a meter.

 

Obviously, having a multi-meter on hand is optimum (and it wouldn’t hurt to have one in your toolbox), but there are times when you just don’t have one on hand.

 

Here’s a way to test AA (and also AAA, C and D) batteries to see if they are new or used up.

 

www.youtube.com/watch?v=Y_m6p99l6ME

 

By simply dropping the battery on its end from a short height (about an inch or so) and watching to see whether the battery bounces can determine if it had sufficient charge.  If the battery is charged, it will not bounce…a spent battery will bounce.

 

Plus, as an added perk…the charged battery will typically stay standing on its end, while the spent ones will fall over.

 

Sadly, there’s no such slick trick for 9 volt batteries.

 

For some other hip info on batteries check out:

 

http://michaelbluejay.com/batteries/tips.html

 

– Jake Kelly