A different battery issue, 992 GT3 - Page 1 - 911/Carrera GT - PistonHeads UK

Hoping someone can cast some thought here as I am baffled.... Put the car away middle of November, attached by 'Porsche' trickle charger to keep it happy, checked on it 10 days or so ago, everything good battery showing fully charged and trickling away.... Went to it yesterday to pull it out of the garage and nothing, the battery appears dead, (Lithium sleep mode perhaps) the charger is on but registering no charge and no attempt to trickle charge, assume maybe i missed a power cut and the battery charger switched of and failed to switch back on. OK I thought no problem that is why I bought a NOCO boost charge, I attach the boost start and nothing, it lights up but does not engage the boost charge, check the charger on my motorbike and it lights up ready no issue so thats working fine. OK I thought its in sleep mode and even though the NOCO is supposed to wake it up it hasn't so I rig jump leads from a GOOD battery, earth point under bonnet and the positive in the passenger footwell hoping the Porsche battery will sense the voltage and wake up BUT nothing and I mean nothing, even with the jump leads attached (correctly good contacts) the car still has no power, No lights no sound all but a very very faint click when I press the unlock on my key fob which when I remove the jump lead is not there, if I were Matt Armstrong I would be thinking the fabled piro fuse..... So I have a dead car (6 months out of warranty) any one experienced anything similar, the idea of having it dragged out the garage (I assume the handbrake will be engaged) and put on a trailer to JCT at Leeds is filling me with dread.. Thanks for your time. Edited by PHOENIXUK on Wednesday 10th December 16:03

I would do a basic check on the battery first, what voltage do you get from it? Nit an iron clad check, but if the battery show low voltage yiu have a good answer. As for the pyro fuse, I'd expect the car to have suffered some serious trauma. Unlikely sitting in your garage minding it's own business...

These batteries do go to sleep if not being charged or used for a while. Are you connecting the NOCO directly to the battery + and frame -? If you're trying to jump the car from the fuse box + then the car won't start from there. Try attaching to the battery directly as above and then turn the ignition on. The car should wake up and recognise a charge. Also, how have you attached your battery maintainer? It's best to use the batter + and frame - rather than the 12v socket in the cabin. Even though you can use it if there is an issue with either the socket or charger then the 12v could stay live. They do not turn off if something is drawing or giving power. I had this a year ago on my GTS 4.0 and I put it down to the 12v remaining live after a power cut (my dashcam was plugged into the other 12v under the glovebox) and it remained live thus draining the battery. Now I use the croc clips and attach directly to the battery.

Rennlist has lots of posts about this. That is why from day one, Jul 23 (Lithium), I have a CTEK on my GTS everyday. Hardwired, not through the useless cigar lighter, but a quick connect via the windscreen. Left, twice, for 6 months and started 1st time. Sorry not helping, but. Rennlist has been over it numerous times so take a look. I think it took another car and starter cables, etc. Even then your BMS may have shut down and a call out and recovery to OPC maybe in order.

Which Noco is it? Basically, the battery needs a higher voltage (say above 12.5v) jolt to wake it up. Some of the cteks have a "supply" mode which sends 13.6v which should do it, others have as much as 15v which when applied for a short period of time can also wake it up. As others have rightly said, directly across the battery and chassis post is best.

scrounger73 said: These batteries do go to sleep if not being charged or used for a while. Are you connecting the NOCO directly to the battery + and frame -? If you're trying to jump the car from the fuse box + then the car won't start from there. Try attaching to the battery directly as above and then turn the ignition on. The car should wake up and recognise a charge. Also, how have you attached your battery maintainer? It's best to use the batter + and frame - rather than the 12v socket in the cabin. Even though you can use it if there is an issue with either the socket or charger then the 12v could stay live. They do not turn off if something is drawing or giving power. I had this a year ago on my GTS 4.0 and I put it down to the 12v remaining live after a power cut (my dashcam was plugged into the other 12v under the glovebox) and it remained live thus draining the battery. Now I use the croc clips and attach directly to the battery. NOCO direct to the batter and frame, yes. Battery maintainer was direct to battery and frame also but as I said I think a power cut may have switched it off and i did not notice, that been said you'd like to think it could go 10 days without.... I decided to jump the car direct from a good battery to the battery and frame, which is what they say not to do BUT it worked the car started and whilst running is working fine, switched off and the good battery taken off and all is dead again BUT this time when the charger is attached it does recognise a battery and 'appears to be charging' shall leave it and see it if it gets any charge, not holding my breath on that but I can hope.. Thanks for reply's

https://rennlist.com/forums/992-gt3-and-gt2rs-foru...

I had the same with a ctek. There is a wake up function but it does not have enough in it to wake the battery. I jumped it from my daughters ve up. I would connect the battery again an leave it for half an hour. Hopefully it will wake up. If not they are £1400. I got Porsche to give me a new one about 18 months ago on my 2019 Cayenne they started with 50% goodwill. My position. Was it was Porsche maintained and the battery was supposed to last 10 plus years. The car was also a daily driver - they tend to decline claims where th car does less than 6000 a year.