996 electrical problem

[colinwdick]

I have a 1999 Porsche 996 C2 that has an electrical problem…can anybody help.
This all started a few months ago and has dragged on as I’m never around long enough to put the car into a garage.

On leaving the car sitting in the garage for a couple of weeks the key remote wouldn’t disable the alarm and the battery just had enough juice to get the engine started.

When the car started it would recharge the battery and all would be OK…you could see from the battery gauge in the dash would jump up from 12 to 14 when the engine was started suggesting that the alternator was doing its bit.

But just recently after doing a round trip of 100 miles using no lights, the car when stopped hardly had enough juice to turn the engine, never mind start the car.
The gauge still jumped from 12 to 14 when the car was started.

Any ideas out there.

[BliarOut]

Battery has had it. A full charge from a trickle charger may get a few more weeks out of it, but basically it's reached the end of it's working life.

[andrew medway]

BliarOut said:

Battery has had it. A full charge from a trickle charger may get a few more weeks out of it, but basically it's reached the end of it's working life.

Ditto. Also, if you continue using it you run the slight risk of damaging the altenator because of the extra workload.

If you are going to let the car stand for weeks, have you considered a battery cut off?

[Mikej]

The alarm goes into sleep mode after 5 or 7 days (can't remember sorry) whereby it stops "listening" for the key remote. If this happens you need to unlock then re-lock the car with the key and then un-lock using the remote - all should be OK then.

[colinwdick]

Thanks - Will replace the battery when I get back from offshore.

Q1. Had a look at the battery and noticed a little breather pipe that’s attached to the top side of the battery…will a Bosch battery have this or should I just get a battery from Porsche.

Q2. What is the purpose of the breather, is it an overflow or fumes?

Any other battery types/makes suggested would be appreciated.

[Vesuvius 996]

I'd get a Porsche one - I hear that they get sniffy if you've got a Halfords special in there when you try a warranty claim for electrical faults.

[BliarOut]

colinwdick said:

Thanks - Will replace the battery when I get back from offshore. Q1. Had a look at the battery and noticed a little breather pipe that’s attached to the top side of the battery…will a Bosch battery have this or should I just get a battery from Porsche. Q2. What is the purpose of the breather, is it an overflow or fumes? Any other battery types/makes suggested would be appreciated.

The pipe is a breather to vent fumes while the battery is charging from the alternator. Any third party battery will also have the breather pipe. Not sure who makes the batteries for Porsche but they definitely don't have their own plant.

[robbie_toys]

If you leave the car standing for long periods, as it sounds like you do, you should condisder getting a battery conditioner, leave it on the car the whole time & it will save your battery. Never a worry about it starting up again.