My battery failed , OK I failed my battery by leaving the ignition on all night and it doesn't seem to be taking a charge. Is there any reason not to go with an AGM battery versus a lead acid. It was about a $20 difference at Costco so I bought the AGM. If it's a problem I can return it no. Meanwhile it will sit until I find out what I should do.

 

Good news, you are fine. Although these are overcomplicated (electrically for sure) cars, they don't care about battery type. Replace it as described in your owners manual and re-learn the windows if needed. Most of these cars have had batteries replaced by the Bosch AGM ones sold at Pep Boys and never a problem.

 

Awesome, Thanks for your help

 

I've only used AGM's in my 997.2S. Never did any coded. No problems.

 

I no longer have a single lead acid battery in any of my vehicles - all AGM. They're so much better. I didn't have to do any coding or even a window reset when instslling them into my 997s or Cayenne.