I have an '83 280 ZX and it goes through batteries like water. In the last two years I’ve had four, in the last two months two have failed, exhaustive diagnoses via my mechanic and AAA always indicate alternator is fine, charging system is fine, everything’s fine and I just keep getting batteries with “bad cells.” There are no coincidences. There’s some other problem. Any hunches?
You could just have a run of bad luck. Are these batteries under warranty? Are you replacing them with the same manufacturer and size? If you haven’t tried an Interstate battery, you might give that a try.
I don’t think you have an ammeter or voltmeter on the dash of your 280ZX so you don’t have a way of monitoring the charging system other than the warning light. I would be concerned that the alternator is intermittantly overcharging the battery. Does the battery use a lot of water?
That is all the help I can give at this time. Hope this helps.
How much is a new alternator? It may be time to change that and see if it was having issues after all.
That’s an interesting thought. Alternator sometimes overcharging! Thanks, I’ll follow up on that one. Yes, batteries under warranty… fortunately, or I’d be even more broke than I am.
My sister was having this same problem with her '96 Honda Civic LX that we had installed a remote start/key entry system into, and we later found out that this system was draining her batteries. Have you installed anything of this nature? Her batteries were fine for five or six years before this problem started, so it could be an old modification sneaking up on you. Good luck!
A battery drain is a sure fire way to end the life of the battery prematurely. Do you notice any things like the radio stays on, gauges keep working, dome lights, brake lights, trunk or hood lights that stay on after the car is shut off?
That seems like a logical explanation especially because the car sits for a week at a time typically. But my mechanic and I went over the car after the third “coincidence” and all we could find was a one-amp clock. If it was a drain I wonder if the problem would consistently be a bad cell. The more I think about it the more I suspect the alternator is over-charging. I’ve disconnected the battery as a way to eliminate the problem you suggest. Thanks!