I put a new Optima battery in my 88 Carrera last Monday. On Friday 10 March, I noticed there was acid coming out of the top of it. I took it back where I bought it and got a new one. Now this one is doing the same thing. Acid is on top of it and it has run down the side and begun getting the battery box wet. I can't figure out why a sealed battery would leak, since they tout it can be located in any position due to the sealed capability. Anyone have any ideas? Could it be the alternator is putting out too much or the voltage regulator has gone south? Any help will be appreciated.

 

most likely, the voltage regulator in your alternator is shot.

 

Would that cause the sealed battery to leak?

 

Yes. The Optima is a glass-mat battery. The acid is a gel like substance held by a fiberglass mat. That’s why you can mount it on its side. If you overcharge an Optima, it will boil over.


Then again, you’ll have problems if you overcharge a dry cell battery…

 

same problem with my brother's old MB. Repalce alternator 3 times. The first 2 alternator were both bad. Wethought it was somethings else, not the alternator. The alternator seller told us "let's try the last time" which is the third time, and it works.
So, if you get rebuilt alternator, be aware.

 

Probably a bad voltage regulator. Glass matt batteries are less tolerant than old lead acid batteries about excessive voltage. Check the voltage at the battery with the car running, if it's above 14.5 volts then that's what's cooking the battery.

 

loose ground will cause this also

 

Update: I replaced the Optima battery with a new one to ensure baseling of the system was done. I replaced the alternator which has an integrated voltage regulator that had 116, 061 miles on it (original). When I was taking the alternator and housing out of the car, I found that the #8/#10 ground strap (wire) that goes from the alternator to the case bolt on the top of the engine was badly frayed and when I touched it, it came apart. It looked like it had been that way a long time and apparently it had come loose and was just laying on top of the case. I put on a new ground wire before reassembling. Eveything is working good now. Don't know if the ground wire being loose contributed to the problem, but my guess is that it did. You never run a car with the negative ground strap loose because it will kill the alternator. It could have been a big contributor to the problem....just a guess. Thanks for all the helpful info and ideas.

 

Glad to hear you've got the problem resolved.