...you might check to be sure you don't have a "load" somewhere.

Although a battery cell can short, it isn't often the entire battery - all six cells at once - will short while it sits unused for only a week. I'd suspect something may be running? I've had symptoms like yours occur when a dome light or the radio was accidentally left on for as little as a week.

If you put a volt meter across the terminals and it reads "zero" or close to it, the battery may just be seriously discharged. It may or may not be possible to revive it when left on a charger for a period of time (2-3days), but in any case it will have suffered considerable loss of life, even if it does "wake up" and take a charge.

My wife's C3 has a light in the cubby hole behind the passenger seat. One time it didn't get closed tight, and the light was on, but could not be seen. (Does your refrigerator light go out when you close the door?). The result was a stone dead battery - read about 2-1/2 volts, and the charger wouldn't initially charge the battery. However, after leaving the charger on for a couple days, eventually the battery revived enough to take a charge, but we ended up replacing the battery a couple months later as it just wasn't the same after that - slow turning starter, etc. (The battery was the one that was in the car when she got it, so it's history was unknown.)

My point is, once you have a battery up to snuff (12.5 volts steady state), use an ammeter and see if there is load exceeding a few milliamperes ("keep alive" current for the computer). Anything approaching a ampere is a sure sign of a problem and it needs to be isolated and repaired.

Then again...I may be way off base. But, for my lack of mechanical knowledge relative to that of others here on Vettes, 'lectric enjuneerin' is my "thing", and that is what runs thru my mind after reading your post.

P.

 

I noticed that the battery charging rate on my 94 dash gauge was approaching the shaded area the last couple of weeks, but the car started okay. I suspected that the battery was going, but hoped to keep it until next spring when it comes out of storage. Then Saturday, when I installed the auxillary hard top for fall driving before the snows hit and subsequent storage, I left the doors open to attach the bolts on the top to the car, and the car would not start - not energy volts from the battery to start. Put the charger on and it would only charge at half the rate it would do if the battery were just run down, and not PbSO4'ed up on the plates. Car started after one hour of charging at the slower rate. So I put the car in the garage, put the battery tender on it to keep some kind of a charge in it, and today I am off the the store to purchase a new battery. The
C4s for some reason can drain a battery over a two week period. It was an excellent recommendation to pin point the amp draw with the meter. I plan to do this after I install it, but before I hook it up. From what I have read on the forum, it is not a great idea to rely on the alternator to charge the battery all the time, so I keep the battery tender on when the car is not driven daily. The forum posts say the C4 alternator is not an especially well made unit; this was news to me. I don't seem to have this trouble with the C5, but I also keep a tender on it too, as I alternate driving them every several weeks. But I have left the interior lights on for about 10 hours and the C5 would not start. Had it jumped started and no problems since. The dash battery gauge shows notmal charging rate. And there is such a wide spread of opinions on the forums as to which battery is best. I know one of my criteria is that the battery must only come with side posts and not the top posts. There is just too little room between the positive top post and metal, even with the protective cap on the post.

 

Purchased a Gold Dura Last from Autozone this morning for $79 after core refund at the recommendations of the forum members. It is made by Johnson Controls and has a thicker case than the ones made by Exide. Checked the Die Hard gold, also made by Johnson, but was $100; the standard Die Hard for $79 is made by Exide. Checked the Autolite battery at Checker, but it is also made by Exide. Decided on the Dura Last Gold with no top posts. Have to install it Saturday, then take the core back for my $13 refund.

 

Update on my battery issue. Took the battery to Sears and testing showed it was a goner. Completely dead.
Got a new battery, top of the line and as suggested, tested for a drain. Happy to report no drain. Put everything back together and good to go. My thanks for all the help and especially JFB about testing the battery.