Battery dies overnight on Craftsman.

[BobRip]

As batteries get old (or otherwise damaged), they can develop internal shorts. The machine can be boosted or charged, and it will start up ok. However, the battery can drain itself from internal shorting overnight.

I'm not saying it's not a good idea to have a battery tested where you buy it. However, if you buy in Wal-Mart, Sam's, or some other big-box store, you will probably get it enough cheaper that you can afford to take a chance on it. Also, these places will usually give a refund if you find the battery is bad and bring it back promptly.

I take a small voltmeter with me when I go to Sam's for batteries. It is not the best test, but it will show a dead cell. That has been the problem on the two that I bought already bad.