PorKen

I needed a battery for the new '80, so I thought it was a good time to ditch the 50lb battery that came with my '81!

The Optima only just fits, with a 1/4" to spare. I hacked up the included battery tray spacer for a temporary buffer and it fits perfectly. I intend to glue a 1/4" rubber pad on the under side of the battery box lid for a permanent solution.


Left | Optima gel-cell 75/25 | CCA 720 CA 910 Reserve 90min | ~35lb ($99)
Right | Autozone 7-year 49-D | CCA 850 CA 1000 Reserve 155min | ~48lb

Pfunde

great battery's those Optima - got 2 1050 amp gelcel's in my boat to turn my 2 DD 6V71TI...- always lot's of power

jpriv928

PorKen,

Just curious how that Optima battery is doing in your 928? I'd love to get one, but Optima's site didn't have a compatible listing for my year. How did you arrive at getting the 75/25? I would like to get the extra cranking amps and reserve capacity of the 34, but don't know if it would have adverse affects on the electrical system.

Thanks for any info.

-Joe
1993 GTS Auto
Slate Grey Metallic
http://homepage.mac.com/jpriv/

PorKen

(Sorry, I missed your reply.)

It's great!

I picked the 75/25 for the size. It's just short enough to fit in the battery box (with a positive terminal guard).

The later battery boxes are not as long (front to back) as the early cars. I don't know if the up/down dimension is the same.

mulik51

Be careful with all these batteries changes. I had a spectrum of electrical problems on my Bronco II. But then I realized that the battery I used was way to powerfull. So, I needed to change alternator and voltage regulators 2 times. Now it is working perfectly. And I asuume, the 928 is a lot more delicate in the woring then 85 Bronco II. So be carefull.

Klim

Champagne

I installed an Optima in my S4 months ago. No problem with cable length or fitment. You need to figure out a way to tie it down since it's much smaller than the original battery. You also need to isolate the metal cover. I used a piece of plastic laminated to the underside of the cover.

Paul

Randy V

What is the weight savings?

Kevin in Atlanta

Optima does not list a battery for the '93 GTS on their website.

Champagne

Optima doesn't list a battery for any 928 but you can still make it work.
All Optimas are smaller but taller than the original batteries thus the need to be creative in both securing it and isolating the metal box cover.

Paul

James-man

Any testimonials of long term use of optimas in a 928 would be greatly appreciated by many here.

Has anyone had "no problems" experience with optima greater than 12 months time?

Thanks!

Champagne

I've had mine installed for 9 months. In that period, I've had projects where the doors remain open for hours and the car itself not even started for weeks. Yet when I needed it, a turn of the key brought it to life without even a hint of a problem.

Paul

James-man

No problems with electroncis such as radios going, etc.

A number of years ago (before Optimas), some people claimed weight savings by using a VW rabbit battery (I do not recall which type), but concerns were raised about voltage stability or amperage or something along those lines, which sounds a little risky.

Randy V

So it weighs the same as a standard battery?

James-man

No it is lighter. People have posted weight savings on other threads, etc. I guess they are tired of mentioning it.

James-man

Porken seems to be reporting a 13 lb weight savings in the initial thread.