[Patrys@BimmerTech]

This should probably go into the Maintenance subforum, but more people will have a chance to read it here.

I have seen pretty a lot of people changing their batteries to save some weight recently and since my battery has just died I have been searching for technical info on how to properly change it.

The conclusion is that if you are going with the same capacity and type of battery then it is enought to initialize your new battery.

If you are also changing the capacity or the type of battery (AGM, regular) then you also have to have the VO changed and the car coded.

The above can only be done by a dealership or somebody with similar diagnostic equipment. I am lucky to have one

I know the car will not break down immediately if you don't do the above but it might have a long term negative effect for sure, e.g. the battery will not be charged with the correct current so it won't last as long as it should, etc.