Persistent "Battery Failures"

electronics

Thanks for the reply. Both seem like better answers than what I get from the dealer, but a bad ground seems unlikely to be the culprit since it would start when jumped and wouldn't start otherwise (unless the ground problem is causing a slow battery drain). The excessive starter draw seems unlikely because there couldn't have been more than 1 second of starter drawing between 'OK' and dead.

Again thanks for the reply.

dave

Do you think there is any possibility that your alternator's voltage regulator is either failed or set too high thus cooking the life out of the batteries over a period of time?

Re: Attached

In principle this has been checked (and the service department appears to be competent). But reality - not so sure. I really need to get a verdict on this battery (is it OK or was the fluid way the heck down or whatever happens to sealed batteries).

dave

electronics

I bet that it's the starter or a battery cable. Your starter probably has a defect where if it lands on just the right brush when it stops turning, it creates a massive short. Or maybe a loose screw or bolt is bouncing around inside of it. The symptoms you describe aren't usually characteristic of a failed battery, espically if this has happened as much as you mentioned. What happens is then as the car is towed to a garage, the rattling and bumping jars loose whatever is goosed in the starter, and at the garage, they stick in a new battery and it starts right up, so they assume it's the battery.

If it's a cable, it could be the cable is shorting to the frame, and is being bumped around, occassionally the short goes into contact. But I would bet it's the starter. I've seen them fail this way before.

What you need to do is take the old battery, stick it on a charger all day and get it good and charged up, then let it sit, unconnected to anything, for overnight. Then in the morning you load-test the battery with a battery load tester. I doubt the dealership is going to bother doing this, (or doing it the right way).

By dumping the power through the battery cables and starter. The heat generated won't even be noticed, as the starter is usually already mounted near a hot exhaust pipe, and the engine will sink away a lot of heat from the starter.

If the battery was dead-shorted, when the tow guy connected his jumper, you would get a massive spark. But if the battery is merely dead, after a few minutes of charging it up from the jumper device, you should have been able to at least turn over the car a little bit.

Ted

Thanks, Ted. The other factoid here is that the last time that this happened they once again replaced the battery (diagnosis - failed battery). I went to a local shop and had a better battery put in (also a Delco, but this one was a six year battery). While the dealer might or might not do this, I suspect that the shop that put the battery in will.

dave

What about a bad cell in the battery? I had this problem with a delco battery. Sometimes it would start fine and other times it would not even crank over. I would try to start it really quick and sometimes it would turn over and start.

fwiw, if it's still under warranty, can you threaten with lemon law type stuff? Maybe then they'll actually find/fix the problem that's killing the batteries? I doubt three new batteries would fail that fast. You have some kind of short/draw/charging system problem that's killing them. I suspect the dealer is just swapping batteries until the warranty expires...

Ray

Three new batteries may fail real quick if they are shelf worn.

What would the dealer have to gain by swapping batteries?

I strongly agree with "You have some kind of short/draw/charging system problem".

electronics

One possibility is that you just aren't driving the vehicle enough to keep the battery charged. 4500 miles on a 2001 isn't many miles. A constantly low battery will sulphate and short the cells. If you have onstar, you probably have all the other bells and whistles that require considerable current draw. If you do drive it infrequently or only for short trips, It may pay you to hook it up to a battery charger at least once a week. Or better yet, buy a maintainer and leave it hooked up all the time.

Actually, in this case I don't believe that this is what is going on. From what I understand the factory pays the cost of the warranty work (have had two items 'fixed' that I didn't complain about) and this is a very small town and we are viewed as potential repeat customers by the dealership.

dave

Oops - 45,000 miles. Sorry 'bout that.

dave

ok, but the dealership is doing themselves a disservice by not fixing it properly. You're pissed. The car looks like a lemon. GM will probably stop paying the dealer for the batteries soon because they're not following proper diagnostic procedures. Then your warranty is going to run out and you're going to be stuck with a huge bill by a real mechanic while they figure out what is shorting and killing your battery. The dealership may mean well - swap the battery and get you back on the road quickly, but they're not fixing the root cause of problem.

Ray

Re: Attached

Based on a short conversation today there is a tentative verdict. It would appear that it is a cable problem (intermittent and never a complete open). I'll have more details tomorrow when I pick up the car (amazingly enough, replacing this cable is a multi-hour procedure).

Will post details when I have them but the folks here were so helpful and prompt that I thought I'd post what I know when I know it.

dave

electronics