Unless you have purchased a volt meter battery checker, knowing how much charge a double A, Triple A, C, or D-Cell battery has was always a challenge. With a 9 volt, you could stick it on your tongue and if received a minor shock, it was good.
Well, there is a way of telling when these batteries are bad without any diagnostic equipment. Simply drop the battery from 1/2" over a flat service several times. If the battery lands vertical and stays vertical, it is still good. Empty batteries will fall over every time. Try it!
Joel Saltzman has over twenty years of wireless industry experience. He is currently CEO and Chief Wireless Analyst for Dr Wireless.