Just sharing my battery change experience...
2007 328i with Navigation, comfort access, xenon lights. The orig battery (90Ah, 900 CCA, the big black one) was showing some sign of wear (the starts would get longer/weaker on multiple short distance stop/start scenarios) and I thought it was time to change the battery anyway (5 1/2 years old.)
Called around, did some research here and there. Autozone had 850 CCA version for $159+tax. BMW dealership had the original AGM 92AH (Excide, BMW part number 61217639053 listed for $290), offered to me for $265+tax ($290 out the door.)
For $100 more, I decided to go with the orig BMW. This was my personal preference in this case, really. I have not been shy of using other brands or aftermarket batteries in my previous cars and motorcycles.
Bought the battery and did the install myself (took me about 20 mins start to finish. This wasn't an internet 20 minutes that in reality takes hours. Started in my garage and opened the trunk at 9:30 am and was done at 9:50 rolling out to work.) It is a heavy battery (the large black one in my case), so keep that in mind if you are not comfortable with heavy lifting. Overall the install was as easy as other batteries that I had done in the past, and everything went clean without any issues. I took some pictures along the way that I share below.
Note in the first post of this thread in Page 1 [[ thank you OP for starting this thread and sharing detailed instructions and pictures, btw ]] the pictures shows a foam pad spacer which doesn't exist in my case, since my battery is the bigger size and fills up the space on its own.
Did some research on this whole registration thing, and decided to go ahead with it at a local independent shop that offered to do it for $65. So basically $355 later, with me doing the install, the battery is new and I am happy with peace of mind that the job was done right (especially since this is my wife's car, and she drives it most of the time, so the extra peace of mind is worth the $$$ difference for me.)
Here are some pics:
New battery: It is rated 92AH and 850 CCA, vs. the old battery's 90AH and 900 CCA. This is what BMW sells now, so they don't have the 900 CCA anymore (as per BMW dealership.)
Old battery in housing:
Old battery out of housing:
The empty housing, you can see the vent pipe (grey) up top:
New battery put in place:
New battery connected:
All ready to go:
