92 Astro, but that doesn't really matter for this question.
Do car batteries get so drained from some tiny short that they can never take a charge again? We're not talking about a cheap or old battery, it's a 7 year Autolite and it's brand new (OK, one week old).
The van was last driven about a week ago and was doing fine. It doesn't go dead from driving, only sitting. It can sit a day or so and start, but not for a week. The alternator and it's internal regulator was checked by two different places (auto parts store & a garage) and was deemed 'just fine'. The store checked it out of the vehicle, the garage checked it installed in the truck.
IIRC, don't lead acid batteries in good shape recover somewhat if there's no drain on them, even if they're run down dead? I seem to remember a Sears commercial where they ran a car battery dead, let it sit for 10 minutes and it started the car again.
If a battery is really severly discharged, getting to take a charge can take some doing. A tee totally dead battery has next to zero resitance in it, and it takes some resitance to get it to charge. Tricks that have worked for me in the past, learned in the service: Use a small charger, ie 2 amp manual or if your automatic will allow set it to 2 amps, and get a spool of wire,say 14 gauge 50 feet long and hook it up between the negative battery post and the negative cable on the battery charger. It might take a solid day before it starts taking a good charge, once it does, you can eliminate the spool of wire. Hook a second battery up to the first battery in parallel, ie positive to positve, neg to neg. and then hook the battery charger up to the pair. again keep the charge rate down, and it make take awhile before the dead one starts charging.
If you draw even a little power for a long enough time, you will drain the battery. Deep discharge is very possible, and that is hard on lead-acid batteries.
The very best thing you can do when confronted with such a battery is to try and charge it *slowly*. It is a little hard to find a battery charger that will go slowly enough. I have a few old ones that I trashpicked and repaired that charge at six amps or less. For a really dead battery, I start with the one amp charger. I recently recovered a partially frozen Interstate battery by putting it over a heat register to thaw out. Then I hooked it up to my six amp charger and let it cook for several days. After three days, it started the very car it came from:
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Using a charger that outputs a high charging current will pretty much guarantee that the battery will be damaged instead of charged up. In other words, don't go and grab one of those "charge up your battery in two hours" models.
Lead acid batteries can develop internal shorts. This usually happens with older batteries and will cause some warming of the case to occur because of the short.
Then you have power draw from somewhere other than the alternator. Have you checked to make sure that *all* the lights are turning off in the vehicle, including the ones in the ash tray or glovebox? Also try pulling one fuse at a time and letting the van sit afterwards.
Yes, all batteries will do that to some extent, but it usually only results in a small recovery--not enough to start a vehicle.
I remember something along the lines of what you are talking about, but I think it actually had something to do with an addition to the battery that could be "switched on" in an emergency to deliver additional power.
I had a similar problem just a few weeks ago and the problem was corrosion on the battery cables. The first battery had served it's life and couldn't be recharged so they gave me a replacement. I took it home installed it; it started. Two days later, it had barely enough power to engage the starter solenoid. I took it back, it checked out good, so they recharged it for me. I took it home installed it; it started. Two days later, not enough power to start again. Took it back again, checked OK, recharged, reinstalled, started and drove it to the dealer for electrical check. They cleaned the connections (which looked pretty good to me) but didn't find anything wrong. It's been several weeks and I haven't had any more problems. So, I suggest a thorough cleaning of the battery connections and checking both ends of the cables to be sure they aren't loose.
Sears Allstate battery had a an add somewhtat like that (the Allstate pre dates the diehard). and then Diehard an ad, but if I remember, the ad showed about five or six variuos vehicles with dead batteries from the lights left on, all then connected to one Diehard Battery and presto they were all sarted at once.
That was a dismall failure, not a bad idea but ahead of engineering ablity at Johnson Controls who came up with it.. It was a Group size 70 in a group size 74 case, the "additional" space was filled with what amounted to a group size 12CH motorcycle battery. a set of diodes allowed both batteries to charge at the same time but only if the switch on top the battery was moved did the second battery connect to attmept a boast. In top post it was a group size 26, or 26F in a group size
24 or 24F case with the same 12CH battery. The heat down here in Florida cooked them all most as fast as they could be installed. Also if the main battery was really severly discharged it still wouldn't start.
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