Removing Battery from 993

[vt993]

Is there any harm with removing the battery from a 993 for a long time (3 months)? Doesn't the computer require a small amount of electricity?

[franklin]

Hello vt993:

I was told by my local Porsche dealer service representative that removing the battery on a 993 is possible for long periods of time but there are some considerations. First of all, the inboard security system might lose its memory and when the battery is replaced, the immobilizer code might need to be reset. As far as I know, the dealer would be required for help on that issue. If anyone can verify/clearify information on this point, I would appreciate it myself. I would especially like to know that if this is the case, (how) can the code be reset at home?

Also, the car's user manual states that when the battery is removed for a period of time, it could take as long as 10 min of running before all the computer restores itself to proper settings. This could cause rough running for those 10 or so minutes.

In the meantime, I have had great success with the Battery Tender which is an advanced battery maintenance system that allows the battery to be left in the car for short or long-term storage periods. Check out www.batterytender.com

Good luck.

Franklin 1997 C2

[vt993]

Thanks for the info. I'll let you know if the immobilizer needs to be reset - hopefully not. My battery died a few weeks ago. Removed the battery but haven't replaced/installed a new one yet - can't drive now anyway thanks to a New England blizzard.

[franklin]

Sorry to hear about the dead battery. Three things:

i) I checked out the voltage drain on a parked 993 and found that there are least three sources; the on-board computer, the clock and the radio all have steady power needs. There may be others.

ii) I will also be looking at the purchase of a new battery this spring and would like to hear if anyone has any recommendations. I am leaning towards the factory battery sold at the dealer.

iii) Anyone looking to save the memory on board while switching batteries can use one of those battery tenders, connect the aligator clips to the battery cable ends before removing the battery and quickly re-connect the replacement battery and all the info should remain intact.

[vt993]

Installed a new battery this weekend. Mechanic at porsche dealer told me that the Sears Diehard International is a great battery and warranty terms are better than Porsche. Went in easy!

Car didn't have battery power for 5 weeks. Put new battery in and the 993 started right up. No immobilizer problems, but lost radio presets (no big deal).

Learned my lesson though. Purchased a porsche trickle charger. Plugs into cigarette lighter and maintains battery. Well worth the $80.

Thanks for your help.