Removing the battery

[blueSL]

My 997.2 turbo is stranded in a private underground car park in London with a flat battery. It's been there for only 4 weeks, so how, I do not know.

Can someone tell me what tools I need to bring there to remove the battery for charging - no power sensibly available where it is. I'm aware I need a 12v power source and cables to blip the bonnet release through the fuse box but what tools are needed to remove the battery and the cables once I've done that? A 10mm socket and extension?

I'd look myself but of course with the bonnet locked, I cannot see. Whoever in Porsche decided not to provide a backup mechanical release (apart from the one in the front wheel arch) needs their head examining!

I'll try recharging the battery but maybe it's gone bad (5 years) and I'll go and buy a new one, but still need to get at it!

 

[angusc]

Hi Mark,

I had exactly the same thing happen to me and I could safely say just buy a new battery and take with you, the old one will be dead for sure. regarding the tools, you will need a 10mm spanner for the battery terminals, and a 13 or 14mm socket with ratchet and long extension bar for the battery retaining bolt. You could make life easier for yourself as well by preparing a cigarette plug on the end of a 2m cable so that you only need to plug that in and connect to your new battery to open the hood.. getting at the fuse box terminal in a dark car park may not be the easiest.

I would take a socket set, Philips, flathead and metric roll of spanners just to be sure. Then buy yourself a battery conditioner that plugs in to the cigarette lighter socket and in to the mains to look after the battery when next you leave the car more than 2-3 weeks.

 

[Lancerlot]

Good advice, except I would just take along a set of jump leads to get the car started and then change the battery in more comfortable and better equipped surroundings.
If you look at the index in this Register's technical section, you'll find links to postings about battery changing and charging.

BTW with modern electronic, locking and monitoring systems installed nowadays, even a healthy battery will often become completely discharged after 2 weeks or so

Regards,

Clive

 

[ralphmusic]

Would a battery booster work - see

http://www.autoexpress.co.uk/accessories-tyres/36199/power-packs-tested

 

[chrisH]

Mark, A new battery is required at this sort of age and would advise you get the Porsche Battery Conditioner (about £35) that plugs into the cigarette socket and can be left on for weeks.
I found it very good for the 987 but your GT3 will rarely need charging as it employs current monitoring and a very large capacity battery like the 981.

 

[angusc]

Regarding the jump lead option, of course it should work but make sure the jump leads are high quality. I purchased a set from local petrol station that looked pretty good to me at the time but found that I was still unable to jump start the car until I attached a second set of jump leads together in parallel! Also be aware if your car is parked nose first in to the parking bay that you might not be able to attach the leads to another vehicle.
For overall ease of the recovery, I still suggest that you take a new battery plus cigarette lighter plug with 2m lead plus hand tools to change battery.

Once new battery is fitted remember the Porsche manual steps to calibrate the steering angle sensor:
1) switch on ignition with steering wheel in straight ahead position.
2) wait 30 seconds, switch off ignition. Switch on ignition and off again twice
3) start engine. Move car out in to area where you can drive forward.
4) turn steering wheel 20 degrees each way then back to center and drive forward above 20KPH for more than 1 second.
5) take car out for drive to clear all other faults (PSM).

 

[angusc]

ORIGINAL: ralphmusic

Would a battery booster work - see

http://www.autoexpress.co.uk/accessories-tyres/36199/power-packs-tested

Oh I know what's on my Christmas list from Santa!

 

[blueSL]

Thanks for your comments everyone. Previously, I have been able to leave the car locked for some weeks and it's been fine. As we know, the remote unlock is disabled after 7 days to save power, no longer true with the 991 by the way.

I think the issue here is that I left the car unlocked and it may be it never goes as completely to sleep as it does when the car is locked.

Anyway, I have a list of stuff to take and a plan.

 

[lamboman]

leaving car unlocked is very likely to be the cause of the problem, as many systems are on standby and consuming power

 

[blueSL]

Thanks to everyone for their advice. As expected, the battery is completely shot.

I ended up using a Halfords jump-starter which has a 12v supply to a lighter socket to open the bonnet. The battery measured around 6 volts and with the jump starter connected directly to it brought it up to around 12v; stereo, lights, remote locking, all fine. Turn the key to the first position, nothing, it was as if an immobiliser had not cleared.

I borrowed an AGM battery from my Mercedes next door and the car sprung into life with a long list of error messages all now cleared.

The battery resisted all attempts to recover and recharge it with a CTEK 10A charger which did not cover itself in glory by saying the battery was fully charged when it wasn't. Peering into the dark recesses of the refilling caps revealed a nasty alien world of brown electrolyte and buckled plates. So, off to the dealer tomorrow to get a replacement.

 

[garyw]

Mark
Mine gave 4 years faultless quality and then one day a cell just collapsed [], nothing could be done with it apart from renewal.
The cell even caused the jump battery to fail to start the car.

 

[blueSL]

Yes, I think that's exactly what happened to mine.

 

[RJKflyer]

Great insight re not leaving the car unlocked. Didn't realise that this was a major issue.

Also, can't help but make the obvious comment that these Moll batteries are shyte. In all my 30 years of owning German cars I have never had a battery fail, and have only replaced one six-year old one as it was obviously on its last legs.

 

[Matt Seabrook]

Just a warning about jump starting cars. It's a last resort in my opinion. I have seen several cars after a jump start that have damaged ecus. One of the first questions I ask when going to a cranking non start as a diagnostic tech is has it been jump started.