Originally posted by rednek
Make sure everything is off, including your ignition, radio, etc. Pull the negative terminal off. Now go to touch it slowly to the corner of the post....if you get a spark, even small, you have something drawing your battery down or have a short somewhere, and it probably isnt a bad battery. If no spark, you have no problem, just get a new battery.
This is the quickest and easiest way. If you want you can also leave the battery post off for a week and put it back on. If the vehicle cranks and the battery isn't dead, It is in the wiring not the battery. Also check for corrosion and wore connectors on the battery. I had the same problem and never could find the draw so I put a battery cut off on mine - helps with someone driving off with your JEEP (no key problem also).
Eric BSCE P.E. (Bachelor of Science Civil Engineering, Professional Engineer)
Just busting, werewolf....I'm an engineer also, but I am the type to go for the simple, easy "fixes" first, especially with Jeeps.
I like to keep it simple and practice common sense. I will, however, keep the battery testing procedures in mind if I ever have the need to go there.
As far as batteries go, I always buy the largest CCA rated battery that sears sells, in "Die Hard Gold", costs about $85 or even less if you catch a sale, and I never have a problem, as long as I don't have a short somewhere.
I do like the battery-cutoff idea, and am considering it for my current project. I have a very slight drain occurring somewhere also, and can't track it down, as is the case with most CJ's. All wiring is brand new, done by the previous owner. I got this Jeep in trade for some parts. I got everything working finally, but I do still have a very small drain. I'll be going the cutoff route I think. THEN I'll buy a new battery, as I am operating on a sacrificial one now.
Draining a battery constantly and then recharging will severely shorten a battery's life, by the way. So, before spending good $$$ on a Die Hard Gold, either fix a draining problem or use a cutoff.