is my battery dead ? - Page 1 - Boxster/Cayman - PistonHeads UK

tried to start the car yesterday but would not start. all the and ancillary electrics are working but the windows wind down very slow. I was able to start the car straight away off jump leading. Later in the day (trying to catch ferry) i cut the engine, as i had to queue, tried to start the cayman but no luck. I had to dump start the car, which did the jump. So is the battery dead ? The car is nearly 6 years old with the original OEM battery

Could be, also worth checking the alternator is charging your battery.

More than likely the battery. Six years on an OEM one is borrowed time tbh.

whats the best way of checking ? would the battery not show any signs of starting to fail?

When my last one failed it was completely without warning. Started it up in work, drove 25 miles home, went to start it three hours later and nothing! If you go to a motor factors, Halfords, etc, they can test the battery for you. They will also supply a better than OE one if you are not tied to an OPC warranty.

Next door neighbour has a 911 just within the 3 year warranty, on Easter Sunday would not start battery flat. Called Porsche assistance they offered home assistance but also stated that the battery was probably U/S and require replacement. No Porsche dealers open so Porsche assistance informed him to go to local Halfrauds to get a new battery and stated it would not affect his warranty as item is consumable?

how many Ah should i go for in a battery if it needs replacing? im thinking of a Bosch

Best to check and see what is currently fitted. I think they are 80 ah but can't recall specifically.

Get a Bosch S5 of some kind. The one I got for my 911 was 305mm. Have a look under the bonnet and work out what fits.

not sure what is going on but have checked the battery and I have 14V so the battery is fine. I was able to start the car but it seemed to have a bit of a struggle turning over. I then went back to the car an hour later and nothing again, the car will not start. I seem to lose power as the clock resets to 12:00. anyone got any idea what's wrong ?

You may have a high resistance somewhere. Make sure all the connections to the battery, starter motor and earth cables to the chassis are not only tight but corrosion free.

thought i'd do a final check on the battery, so i swapped over the battery from my Mini Cooper S. Its a smaller battery but hey presto!! Cayman started first time Will replace the battery over the weekend, thinking of a Bosch or Exide 72Ah, what do others suggest ?? (hoping this will solve the problem)

A Bosch 80 Ah will be ideal

thanks Trev, really appreciate yours and others input here's hoping a new battery will get my car running again, so that i can hear the tones of my new carnewal gt exhaust.

The Porsche batteries seem to last about 3 years and cost £250 to have replaced at the OPC. If you don't have a Porsche warranty to maintain go for the Bosch battery instead, it's better I hear. I had similar symptoms to you early this year. The battery voltage was about 11.5 volts so the OPC replaced it. Everything was fine until last week when it started playing up again. The battery voltage is 12.5 engine off, and 14 volts with the engine running, so no problems there. It refuses to start first turn of the key, all the lights go out, the clock resets. I researched it on t'internet and found on planet 9 a few people with the same problem. They noticed that just touching the positive battery lead restored power and they could get going. So I tried the same thing in Sainsbury's car park yesterday, when it refused to start, and it started immediately. All the people have 07 or 08 Caymans/Boxsters, which fits with my 07 Cayman. The cause of the problem has been tracked down to a distribution box located behind the glove box. The positive battery cable is connected to this box and can get corroded and give a dodgy connection. I suspect a new battery, full of volts, can overcome this resistance due to corrosion for a while, then as it settles down the problem comes back, or moving the cable about while changing the battery breaks down the corrosion enough to help it start, likewise attaching jump leads to the battery. While the engine is running there are no problems because of the extra power from the alternator. So mine goes in for investigation under warranty next week, but I'll be pointing them in the direction of the distribution box. Fingers crossed that will fix it. I'll keep you updated. Edited by AndrewsCayman on Monday 13th April 13:52

thanks Andrew, that seems to make sense. who is doing the investigative work?

Porsche Centre Bolton

Would be great if you can post your findings. If its the box your refer to, it would be great if you can ask Bolton OPC to photo the troublesome connector. cheers