jeffc2731

Had to replace the original battery on my 2010 997.2 earlier this year. When the battery can no longer hold a charge, it happens very quickly - the previous day, the car was driven for a few hours; the next day, the car would not start. Checked out the alternator and all was good.

The various posts on Rennlist were a big help, but I could not find many pictures of the battery and battery compartment. I've included some pictures as well as a few notes that others might find helpful.

Notes:
- For an exact fit, the battery should be 12-3/8 (length) by 7 (wide). The Interstate Megatron Plus (MTP-94R/H7) is a perfect fit. The hold-down bracket fits right over the extruded plastic base (see pic). Cost came out to $200 after tax.
- Definitely ask the store for the newest battery they have - check the date code.
- As mentioned in other posts, there are other holes for the hold-down bracket but they are not usually threaded. In my car, only the middle hole is threaded.
- The 'PSM Failure' warning will clear one the car is driven.







Only middle hole is threaded.





Hold-down bracket fits right over the battery base.





All done.

mrhebert

Check you overflow drain, may be clogged. It looks like a lot of battery water has flowed on your battery tray. It should be spotless except for a little dust.

jeffc2731

Are you talking about the vent tube?

TRFALK

Yes, check the vent tube. Looks like you have had some battery acid spill in your tray rather than run out the vent tube, either because it wasn't connected or it's clogged. That's likely what has caused your tray to corrode. I would suggest replacing your tray as it is likely brittle from the corrosion.

Pep Boys carries a Bosch Platinum AGM battery that fits perfectly at well. You can get if for less than $200 with a coupon found online.

3Series

Or Walmart for ~$115 , non-AGM and you get to pick the battery yourself so you can check the date code.