997 Battery Problems - Page 1 - 911/Carrera GT - PistonHeads UK

Recently bought a gen 1 997 (circa 2006). Understood that the battery was not the original, i.e not very old. After leaving in the garage for a couple of days I found the battery dead. Successfully recharged but a few days later the battery failed on attempting to restart the car when hot (after a run of 30 miles). On advice I bought a battery refresher from Porsche which I have been using nightly. Battery has charged successfully and car started ok each morning. Today I stalled at a roundabout (whoops!)and again refused to start - battery dead. Restarted courtesy of the AA. When I got home I left the car for 5 minutes after which it started perfectly. I then remembered that the common denominator between the times when the battery failed was that the car lights were on. Tried to start the car again with the lights on and - failed to start! Being a bit of a novice in these affairs I would welcome advice as to whether this is a simple failed battery or could their be something more sinister at play. I can understand a battery dying overnight but not after a decent run. Would welcome any comments.

I've just had exactly the same on my 997.2 - OEM battery was five years old and just not up to it any more. I ran it through a recon cycle on my CTEK and that helped a little, but a brand new battery in yesterday has made all the difference. Replaced the pathetic Porsche-branded Moll Kamina with a Bosch S5 with more than twice the cold cranking amperage reserve.

Both my 997s had batteries go dead. Replaced them with stronger non-OEM batteries and no probems since.

Technomad said: I've just had exactly the same on my 997.2 - OEM battery was five years old and just not up to it any more. I ran it through a recon cycle on my CTEK and that helped a little, but a brand new battery in yesterday has made all the difference. Replaced the pathetic Porsche-branded Moll Kamina with a Bosch S5 with more than twice the cold cranking amperage reserve. The pathetic Porsche-branded Moll Kamina battery didn't do bad to last five years!

I had similar problems with mine, was a 2 year old Porsche battery, never great cranking and had me stranded once. Finally got annoyed with it enough to change and put a Bosch s5 in it 3 weeks ago. Difference is night and day, only 3 weeks in but can't believe I put up with that crap for 18 months! I do however have a slight issue with my interior lights not going out when the car is 'on' (have them manually off now) and my right ear no longer works after disconnecting the battery without the key in the ignition...

Martian O said: The pathetic Porsche-branded Moll Kamina battery didn't do bad to last five years! But they are pathetic from day 1. Try a Bosch and you will be left scratching your head as to why Porsche stick with Moll - must be owned by a family friend!

drmark said: Martian O said: The pathetic Porsche-branded Moll Kamina battery didn't do bad to last five years! But they are pathetic from day 1. Try a Bosch and you will be left scratching your head as to why Porsche stick with Moll - must be owned by a family friend! I do agree, I too have a Bosch Silver battery. Just questioning why the comment about a battery that lasted five years is pathetic .

Fantastic responses - many thanks. Symptoms identical to those detailed in the posts. Should have added that the current battery is an OEM and I've been using CTEK charger overnight. You've taken a weight off my mind and I'll get a new battery tomorrow. First time I've used the forum - very, very impressed.

Batteries on Porsche seem to go max 5yrs if you are lucky, I get probs on other machines too, they need to start putting more lead in them and less plastic. Weight ( or lack of it) gives it away.

I had a similar issue that seemed to be caused by my phone charger being plugged in the centre console draining the battery if left for a week. (Not the ashtray lighter the one in the centre).

Many thanks for all your advice. Just to close the loop on this one. Decided to replace the Moll Karima battery with a Bosch Silver Plus. Since then I've had no problems.

shayman said: Recently bought a gen 1 997 (circa 2006). Understood that the battery was not the original, i.e not very old. After leaving in the garage for a couple of days I found the battery dead. Successfully recharged but a few days later the battery failed on attempting to restart the car when hot (after a run of 30 miles). On advice I bought a battery refresher from Porsche which I have been using nightly. Battery has charged successfully and car started ok each morning. Today I stalled at a roundabout (whoops!)and again refused to start - battery dead. Restarted courtesy of the AA. When I got home I left the car for 5 minutes after which it started perfectly. I then remembered that the common denominator between the times when the battery failed was that the car lights were on. Tried to start the car again with the lights on and - failed to start! Being a bit of a novice in these affairs I would welcome advice as to whether this is a simple failed battery or could their be something more sinister at play. I can understand a battery dying overnight but not after a decent run. Would welcome any comments. Glad you got it sorted. I had a similar one that apparently is also quite common on the 997.1 - when hot it cranked slowly and would barely start - but when cold it was fine. This turned out to need a wiring loom replaced under warrantee. Apparently the connectors get a bit crappy when hot. I recently had to get a new Porsche battery - would rather have gone for the bosche, but didn't want to mess with the warrantee. Guess I can't complain - the original had 6 or 7 years on it.