Battery issues

[mbagge01]

I have a 2004 cayenne turbo with tune and few mods. For the longest time I have had issues which felt like timing being pulled and surging under boost. I did all the usually things checking for vacumn and boost leaks, etc. and could not find anything. About 2 years ago I had replaced the battery with a duralast gold lead battery and over the past couple months started getting issues with the battery being dead when it was cold out and I assumed battery was going bad. Even before the battery was dying, I was getting the surging issues. Strangely, everytime I would reset the DME from disconnecting the battery or through durametric, the car would run great with smooth acceleration and no surging. Unfortunately, it would only last for about 10 minutes and surging would come back until DME was reset again. I just recently replaced my battery with a duralast AGM platinum and all those driving issues went away and I have not had a problem since. I know that the cayenne is sensitive to weak batteries and weird electrical things can happen, but am I correct to assume that when the car is running, everything is powered by the alternator and independent from the battery, unless the battery still plays a role in powering certain things? Could the electrical signals for timing, boost, fuel etc be impacted by a bad battery. Also isn't the OEM battery an AGM and could running a lead battery cause issues.

 

 

Edited October 27, 2019 by mbagge01