95_993

Will my little Schumacher battery tender do the job??

Email Cup944@aol.com to find out.

DocTock993

Should an Optima Red Top make a "hissing" noise when on an appropriate CTEK charger ?

cosmic_993

just got my yellow top via the Rennlist GP. Sweet deal !

MW

IXLR8

Ideally, they should have a higher cutoff voltage if I remember reading Optima's specs correctly. That also goes for the voltage regulator in the alternator.

I just bought a CTEK MULTI US 3300 charger because it has a 14.7V mode for those batteries and for charging in colder temperatures such as during winter layaway. I bought it for the latter reason.

Richard C2S

FWIW, I've had a red top in my 993 for several years now with no problem. Of course, now that I've said that, it will probably crap out next time I try to start the car. Mine is an 35/25, I think, which fit perfectly. I have used a Porsche (C-Tek) battery maintainer.

I don't think the 35/25 is made anymore. Which model red top is "the right one" for a 993?

Thanks.

Richard C2S

Actually, my red top is a 75/35 OR, not a 35/25. Sorry.

RickBetterley

Old thread, time for an update.
My track car came with a yellow top; it dates back to fall of 2005 and appears to only now be failing. I have always kept it on a battery tender.
Time for a new one. Is it it a model 35 for the 993?
I finally figured this out - my battery is the model 51R (R means terminal on the right side) BUT this is a smaller battery used for the race car and may not be the same as what you might want for the street (we are after light weight more than for powering electronics).
Amazing that the Optima web site has no recommendation for the 993.

H.H.Chinn

I've had an Optima red top battery in my car from the previous owner where it's about time to replace after seven years as it doesn't seem to hold a charge for more than two weeks when the temperature dips below 40 degrees farenheit but it's fine when the temps are up in the 70's. With a sealed battery I don't have to worry about battery acid damage from a leak or having to make sure it is properly vented.

Mike J

Hate the optima batteries - went through two fairly quickly, both failed, put in a $60 lead-acid battery (cheap because of a case blemish) and vented it properly, it has worked great every since.

I see others had had better luck, for for me, if your charge system works great and you vent, stock batteris work great and are very cost effective.

Cheers,

Mike

IXLR8

I hate to break it to you, but those so-called "sealed" batteries are vented as well...and they can leak...and you do need a vent to the outside for safety reasons.

Edward

Ancient thread, but I have to chime in an agree with Mike here. I likewise went through two Optimas, both in cars with perfectly good charging systems, and both crapped out prematurely. Yet ALWAYS had good experiences with decent conventional batteries. Never again on these overpriced lead weights!

Edward