I've learned that when it comes to batteries, you get what you pay for.  How many times have you purchased some cheap batteries to find they work a few weeks and go dead?  Or my favorite is when you're not sure if a battery has any life left in them.

So here's a quick 30 second video that makes it easy for anyone to test those AA, AAA's, C's and D batteries.  And it only takes a couple of seconds.

Let me know if it worked for you.