I put a new Optima Red Top battery in my 993 about 3 years ago and after 2 years it seemed to stop holding a charge. I had it replaced on warranty at no cost; but now my current Red Top is also not holding a charge.

Sometimes I don't drive my car for a few weeks at a time - but it seems like a battery that is less than a year old should be able to retain a charge for a few weeks.

How can I determine if my charging system is at fault or if it's the battery?
Is there a better battery to use?

 

Probably the battery. I've had nothing but problems with the Red Top. Gone thru 3 or 4 in as many years (2 different 993's). Mine get weak after 3 weeks too.

Have you checked current draws when off? That's one thing I need to do.

 

In the owners manual it says to lock the car all the time. This turns off the drive block system. If left on you will have a draw. Try that.

 

+1
My car had a Diehard in it when I bought it. It was old, I let it go flat a couple times (took a LONG time) and it was a goner. I wanted the BEST battery for infrequent use, so I bought an *Optima*. Yea, problem solved!!! Yeah, right. After two attempts (Red Top, Yellow Top, they both failed in a short time), I went to NAPA and got their standard 75 mo. battery - $72 with a discount coupon I had. So far it's outlasted the Optima's. Total POS's if you ask me.

 

I think part of this is that not all trickle/floating chargers are up to the job for gel batteries. I'm not sure what the issue is but I had repeated failures with my red tops until I upgraded my charger to one that specifically said it worked with gel batteries. Two years on now and no problems (yet).

 

Odd since Optima is not a gel battery. It's just a sealed battery.

 

My Optima red top lasted less than a year. And I keep my doors locked when the car is in the garage.

Curiously, my far less expensive, generic Advance Auto battery (made by Johnson Controls) has served me quite well.

 

I have a heavy equipment rental company and we only use the Optima batteries in equipment that has sever vibiration that is what they are good for. They perform no better than a good standard battery. In fact standard batteries last longer. And if you want a battery that can be drained down and recharged in cycles you are best of with a deep cycle battery.

 

Optima's are AGM batteries which require totally different charging regimes.

Recharging an Optima with a standard, normal charger shortens its life appreciably so one should use a CTEK charger that will do AGM batteries.

I have two of them in various cars including my 911 and I typically get 4-5 years from each one. I do use disconnect switches to prevent small current draws from depleting the battery during long periods of storage.

 

Actually I believe they are gel - that's why you can presumably break them open and they won't leak. A sealed battery is just that, a regular lead-acid battery with no open vent.

 

I thought I had a problem with my odyssey 925 battery... but as it turns out, once I installed a battery cut-off, the problem has resolved.

 

I have been leaving my car unlocked in the garage thinking I was saving the battery. Duh. Guess I should re-read the manual.

I had an Optima Red Top that last two years and was replaced under warranty. I used the regular porsche charger on it numerous times. I'm doing the same thing with my current Optima battery. If this battery doesn't perform any better, I'll be going back to a 'regular' one.

chuck

 

Chuck - I have the red top and Porsche charger also. The first red top lasted less than a year, the second one is now going on it's third year (I think) w/o any problems. I think quality control is an issue with those guys.

 

Third year-that's good to know. I plug in the charger and it never really 'runs' that long. Seems like this battery is holding a charge pretty well.
Good to hear from you Bob.

chuck

 

Third year-that's good to know. I plug in the charger and it never really 'runs' that long. Seems like this battery is holding a charge pretty well.
Good to hear from you Bob.

chuck