Railmaster.

Seems like almost every 993 got this option! Mine as well! Was the M197 Stronger batery option ordered by the customer or was it standard for certain markets?

When I bought a new battery for my M197 optioned car this summer the stronger battery for my car that Porsche handed over to me did not fit! it was too big so I had to install a 70Ah battery which is actually smaller than the standard battery in 1994 which was something like 73Ah.

IXLR8

Group 48 or 91. Both have the same footprint but the group 48 is 190 mm tall compared to 175 mm tall for the group 91

The group 48 battery is typically 70 Ah.
The group 91 battery is typically 50 Ah.

The CCA of both about 600 to 700A.

Railmaster.

Thanks! But the M197 battery is 80 Ah? Isn't it? Is it possible to find a 80 Ah battery today that actually fit in a M197 993?

IXLR8

I don't know other than the non-official owner generated M codes lists that I have state "stronger battery". If you've come across a Porsche generated M codes PDF that actually shows the Ah, then you'll know for sure.

Measure the foot print size in your car and then go to a BCI generated battery list to see what might fit.

Besides, why do you need more Ah when the stock 50 or 70Ah batteries work just fine. Unless you are in the battlefield with your 993 in silent watch mode.

If your alternator and all wiring connections are fine and you do not have abnormal electrical drain, stock batteries do the job.

Railmaster.

I bet You are right! But why is almost every 993 sold with the M197 stronger battery option?

IXLR8

Mine wasn't. No M197 code on my options label.

I believe mine came with the 50Ah battery and a subsequent owner (or dealer) had a 70Ah battery installed which is too high to clear the plastic apron panel (it needed to be shaved or bent slightly aside).

Cupcar

No M197 code on my car either.

Parts list only lists two battery types for 993 one a 75 AH for all cars but Carrera RS which used a 36 AH battery.

No mention of a 197 code application for 993

Did that change?

Railmaster.

Thanks! Lots of M197 993s in the pricing thread above, will check my cars specification when I come home! Maybe Porsche only offer 80Ah and 70Ah batteries taday and the 80Ah is too big for the 993 and the 70Ah slightly under the original!