Battery Replacement

[michael.williams1]

Having experienced a number of random fault codes on my 987.2S I've been monitoring the strength of the battery. It's 3 years old and will get up to about 12.3V max after a good drive but will fall back to 12V overnight. I do not keep the car on a CTEK as it's in constant use; I prefer to drive it! I've been looking into changing the battery myself and have read the instructions in the workshop manual, which require various resets to be made due to memory loss from power disconnection. I'm surprised they don't suggest using an OBD2 memory saver. I can't see any reason not to do this ... unless you guys know any better?

 

[911hillclimber]

If this helps, I changed the battery on my 987.2 2.9 Boxster a few years ago.
Out with the old, in with the new fully charged battery (Bosch) and the terminals were disconnected just about 3 minutes or less.

I had no faults show, and the car was fine.
I recently did the window winder mechanisms which meant a disconnect to allow the air bags to become safe as well as the 90 mins or longer to free the door cards etc off, fit the new system and reconnect, it was possibly longer than that, not a straight forward job for me.

I had to set the power steering sensors (drive forwards very slowly turning the wheel left to right and the light went off).
The window drop positions had to be reset, 30 seconds, but iirc that was it.

No OBD2 etc was needed.

I think someone on here has made a list of what is likely to fail and how to reset the functions so the dash lights go away.

Good luck!

 

[malarcy]

I have done battery swaps on two 987.2 cars.

Using both methods (memory keeper and straight swap) - both were fine - and to be honest the window limit relearn, the steering angle sensor relearn and the (sometimes missed) throttle adaptations (turn the ignition on, don't start, leave it for 30 seconds, off, done), and resetting the time is for me less faff than hunting another 12v source to power the memory keeper. I can live with losing the trip counter data.

And personally, whilst I know its a well trodden path, and 1000's of people do it and the wiring is such that its fine, I just don't like putting 12v into the obd port - feels "sketchy" to me. When I did it, I used the ciggy lighter - which is far from sensitive electronics - but as I say - did it once - wouldn't bother again.

 

[Motorhead]

Sound advice above Michael. The only thing I’d add is that the battery is very heavy [~20kg?], so to avoid straining your back I’d jump into the boot well to lift out the old battery and replace the new.

Don’t forget to reconnect the vent pipe.

Jeff

 

[michael.williams1]

The new battery is in! £133 from Halfords who took the old one for recycling. It has a 5 year warranty on it which could be useful as the Bosch battery only lasted 3 years. I decided to install it without using the OBD2 memory saver and it was quite simple to reset the throttle, PSM, windows and clock following the instructions in the workshop manual. The new battery was a slightly tight fit in the tray which took a bit of time and persuasion. I also had to pull the vent hose across to fit on the other side but Porsche had allowed for that. Don’t know if it’s a “placebo” but it does feel like the car’s driving just a little bit smoother now!