Optima Red

[Mrdi]

I have a red Optima with the special AJUSA mounting bracket.
Seems like it is about three years old and now holding a charge for only a week.
Seems a short life span for an Optima .
Anything better out there?

88 911

Mrdi

[Lukesportsman]

I have both Optimas and Odysseys....I've had better luck with my Odysseys, but they cost about twice as much. I run Odysseys in my track cars now and Optimas in my drag car just because they are cheaper to run in a dual setup. If you change, though, I doubt the mount will cross over.

[911pcars]

Are you sure it's the battery? Maybe the circuit is discharging it.

Sherwood

[thabaer]

My Optimas didn't like to sit around for long without running the car, tried an Odyssey in the same car and it died faster. Same car, no changes with a conventional wet sat for months and started right up. ~10 mA drain for ECU memory, radio memory and digi clock.

Edit: that was with the Red tops, Yellows are deep-cycle and are recommended for infrequent use and greater discharge environments.

[911pcars]

Mrdi,
You can't diagnose your battery based on what happened to another car.

Make sure you don't have a parasitic current drain.
Make sure the battery is being charged adequately.

If the above are okay, have the battery checked professionally. If it's bad, replace it. Check the warranty. My red top lasted 9 years. YMMV.

Sherwood

[RoninLB]

Originally posted by Mrdi

Seems like it is about three years old and now holding a charge for only a week.

3yrs old for a Calif red top doesn't seem long. I'd start with Sherwood's suggestion as a start to see what your dealing with.

makes no sense to me ruining a new battery. Running down a "starter" battery weakens it permanently.

Deep cycle is another story big time.. short answer is they don't belong in our cars 99.99% of the time.

you could also remove it and have it load tested.

[Mrdi]

I should be able to check the discharge draw with my Fluke 111 multimeter.
Touch the neg and Pos to the car terminals after the neg is disconnected from the batt. ?
What settings on the multimeter.?
Whar should the meter read?
The radio goes OFF with the ignition.

[Mrdi]

How do I measure parasitic drain w/ a Fluke 111 multimeter

[RoninLB]

"101 Projects for Your Porsche 911" by Wayne R. Dempsey

p218

[911pcars]

I should be able to check the discharge draw with my Fluke 111 multimeter.
Fluke is fine. Any multimeter is okay.

Touch the neg and Pos to the car terminals after the neg is disconnected from the batt. ?
Yes, connect plus and minus test leads to neg. battery post and disconnected ground cable.

What settings on the multimeter.?
Measure current (amps)

What should the meter read?
<50-60 Ma

The radio goes OFF with the ignition.
Yes. Unavoidable after disconnecting the ground cable.

If the ammeter reads more than 50-60 Ma, remove each fuse in turn to isolate the circuit that draws excess current. Realize that many Porsche circuits are not fuse-protected (e.g. ignition, headlight) and electrical accessories like aftermarket alarm systems are often the culprit. Consult a wiring diagram to see what circuit the fuse "protects". You can further isolate by disconnecting various loads (accessories) from the circuit until you discover the source of excess current flow.

It's easier to buy a new battery, but if it's the electrical circuit, you'll be back to square 1.

Hope this helps,
Sherwood