4howard

I dont start my 91 as often as I should. I got tired of dealing with the dead battery, so I decided to disconnect it between uses. Three weeks later the battery is dead anyway. Here's the question, should I replace a three and a half year old 750 CCA battery that's had to be recharged at least 6 times? Or, keep the battery and hook up a tender. If I replace the battery I am going to hook up a tender anyway, just don't want to toss a still usable battery.

Happy Thanksgiving!

c4cruiser

How do you know the battery is "good"? The fact that it won't hold a charge for more than a few weeks can mean either the battery is bad or you have a current drain that is causing the battery to go dead.

Given the fact that you said that you have had to recharge the battery so often, a tender is not going to solve the problem.

Charge the battery, re-connect it and take the car to a reputable shop (not AutoZone or O'Reilly's or other chain auto parts stores) where a load test can be done on the battery. Also have the charging system tested to make sure the alternator is working properly. A shop with a tech that is experienced with electrical systems can find out if there is a current drain somewhere.

powerpigz-51

It only takes a few times of running a new battery completely dead to fry it permanently. If it won't hold a charge disconnected, time for a new one. And a tender is the way to go, Vette's seem to have a pretty good discharge rate when allowed to sit. And a battery must stay fully fully charged for long life.

jfb

Lead acid batteries self discharge even disconnected. If you keep your battery charged up using a battery tender you will experience normal battery life. If you let the battery sit until it is dead, then recharge it, and repeat, you will experience short battery life. Lead sulfate collects on the plates during discharge and left sitting, the lead sulfate becomes hard and lead sulfate is a good insulator and will not convert back to lead and sulfuric acid upon recharging like occurs when you recharge immediately. Sulfated plates reduce the battery amphour capacity and after a few deep discharges you effectively have a motorcycle battery.
You can try recharging your battery and finally putting a tender on it and you may be ok, but if you don't want to get stuck somewhere, I advise you buy a new battery and take care of it.

aklim

Absolutely true but I doubt that it is a battery drain from the car because he said he disconnected it between uses. That kinda narrows it down to a bad battery or alternator. I would think the battery should be removed, charged to the max with the tender and brought to the shop for testing. If that passes, have the alternator tested.

powerpigz-51

Very true....I guess I meant not holding a charge at all or very short term.....

4howard

Sounds logical, do you think the voltmeter on the dash is any indication of alternator output? It reads close to the max, somewhere around 16 or 17 volts.

hooked073

Two things. First did you run your car long enough the last time you ran it to charge the battery back up? The other thing is you said that everything was diconnected. We keep batteries on the shelf sometimes for over a year a good battery should not have any problem sitting that long with out any problems. So either the battery did not have a good charge before you disconnected it or your battery is going bad.

4howard

I gave the battery a good charge prior to using the car during the summer. I used the car a couple of times after that, disconnecting the battery each time after using the car. The last time I used the car, it started right up, drove it about an hour on the highway and then disconnected the battery when I parked it. My gut feeling is the battery should have enough to crank the engine a little bit.

hooked073

If your charging system was working the last time you drove it and hours drive time is more then enough to charge the deadest of batteries. Sounds like you have a battery going south. I do not know the full history fo your car. But unless you have an abnormal draw you should be able to let your car sit for at least a month without disconnecting anything. If it will not sit this long and start you may want to get a draw test done. A battery tender does not hurt at all if you seldom use the car. Hard wire it in and plug it in when you are done driving it does help.

4howard

I am inclined to agree. The car has 8000 miles and never gave me electrical problems. Thank you and everyone else who has contributed. Off to buy a battery and tender on Monday.