2011 c300 - do you need to keep system energized while replacing the battery?

 

The Forum has posts that claim either replacing battery w/o a backup was without any problems while others say that resynching the windows, sunroof and sometimes ESP is needed. I got a $40 electronic battery charger from Harbor Freight which has several functions, including AGM battery charging. I didn't feel like having to resynch things if in fact that would be the case on my 09 C300 so I hooked up the charger to my remote +/- terminals and changed out the battery w/o a glitch. The attached link gives an overview and talks about resynching procedures.

http://www.mercedesmedic.com/mercede...placement-diy/

 

I just replaced the battery and had no problem with the windows or the radio or anything else. It just took a few minutes.

Nelson

 

I also recently replaced the battery. All settings remained with the exception of the trip meter.