GT3 battery woes - Page 1 - 911/Carrera GT - PistonHeads UK

Battery flat - my fault - NOCO boost gets it going - run car for 20 mins but battery won’t hold charge, it seems. Am I wasting my time trying to trickle it now? Any pointers welcome. Suspect it needs new. Car is 2018 gen 2 992 gt3

I think once they have gone completely flat more than once they are generally done for and I think the lifespan is only about 6 years anyway. Other experts will be along shortly I am sure. I would have taken it for a longer run than 20 minutes (30 to 60 mins). Also I would try the trickle charger on overnight basis and have a look the next day. With the engine running the voltage at the battery should be between 13.5v and 14.7v otherwise maybe the alternator isn't doing its job. Pip

Hiya, if it's a 2018 GT3 (nice car but a 991.2?) battery has probably failed through age. I've had some success using a CTEK charger with a recondition option to revive batteries - I use my 2015 981 GT4 battery to power electric fencing and it is still going strong despite sitting in fields in sub zero by regular use of CTEK's recondition programme. The Liteblox battery I bought for my GT4 is now running happily in the GT4RS after about 6 years of ownership. These, and the Antigravity equivalent - which are more competitively priced - have run flat protection and can restart your car if you let this happen with, it seems no ill effect. If you are like many of us, limiting the miles while this bloody rain remains unstopping, maybe a new battery and get a CTEK charger attached to it directly under the plastic tray in the frunk and your battery will last forever! I have read here that Porsche can disclaim warranty claims if you don't fit their battery; when I bought one from Porsche West London, it was about £300 - mybe you can get a PCGB discount. It's a lot more than a Halfords job but..... A Liteblox is roughly £2k and an Antigravity is c£1k. I see that ninemeister has launched a Lithium battery range too.

The thing I find a pain is even where charged, when a battery starts to age this can't easily be detected with a simple voltmeter because the battery needs to be under load to show its true colours. A useful tip I learned was that the battery voltage when starting the car (under this load) should hold over 9v which is the voltage required by most ignition circuits ... the danger often at the end of battery life is that the car will start if it starts first time but if this fails you are really stuck.

It might be worth running the recon mode on a charger. My car is a 991.2 and it's still on the original battery. The previous owner kept it on a CTek and I do the same and I've measured the voltage it's still fine.

As mentioned. Run a recon using a CTEK and see how it goes.

The thing is with modern cars, a battery on its way out will also start to throw random fault codes too. Plus, a high compression 4 litre flat-six takes a fair bit of cranking. The systems are so sensitive and the battery life is so finite, as others say, at 8 years there's probably no other decision. CTEK is good for keeping a decent battery in good order, but it won't work miracles on one that's at the end of its service life.

It's nearly 8 years old. Time for a new one before it lets you down badly. The CTEK may revive it a bit, but you are on a hiding to nothing IMO. Edited by MinchCS on Monday 23 February 09:41

No, but for one that is, all you need to do is feed it 150,000 amps .

Popolou said: No, but for one that is, all you need to do is feed it 150,000 amps . "Great Scot!! 1.21 gigawatts!"

scrounger73 said: As mentioned. Run a recon using a CTEK and see how it goes. another one for this - if you can disconnect the battery when you do this its giving it the best shot.

MARTIN993 said: run car for 20 mins but battery won t hold charge As others have said, it needs desulfating with the function on certain CTEK and NOCO chargers. This can work but if it doesn't then you will need to replace the battery. Snowy999 said: I use my 2015 981 GT4 battery to power electric fencing and it is still going strong despite sitting in fields in sub zero by regular use of CTEK's recondition programme. That's interesting to note. Always wondered if they could be reused based on the reconditioning programme. My NOCO has brought a dead battery back (was holding just 7V but now sits at 12.6V for weeks) - wondered what to do with it. I ought to test it to see if it has any cranking power in it.

1. Charge it until full (if possible). 2. Use a battery tester to measure CCA. CCA is what matters, voltage can be misleading.

Buy. A. New. Battery.

Nurburgsingh said: scrounger73 said: As mentioned. Run a recon using a CTEK and see how it goes. another one for this - if you can disconnect the battery when you do this its giving it the best shot. Thread resurrection - bit of a question for a recond ctek run : does the batt absolutely have to be disconnected to do so....?

No. Just attach it to the +ve terminal on the battery and the -ve post on the chassis and select recon on the CTEK. The charger will do the rest or you could just turn it on. It will do a desulphate as part of the conditioning but for a full recon you'll need to select it. CTEK say you should run a recon once a year.

scrounger73 said: No. Just attach it to the +ve terminal on the battery and the -ve post on the chassis and select recon on the CTEK. The charger will do the rest or you could just turn it on. It will do a desulphate as part of the conditioning but for a full recon you'll need to select it. CTEK say you should run a recon once a year. thank you, i was wondering if the higher voltage on the recond meant it might be a problem and i could get away with not disconnecting the thing. annoyingly, the 7rs batt has went completely dead (admittedly my fault) so just thinking of how best to get the bloody thing charged up now.