This answer is applicable for many BMWs in addition to the one listed below.
car year: 2005
car model: 545i
Is it critical to register an aftermarket battery after a DIY swap? If so is there something at Bav Auto that can do this to save a 60 mile trek to the dealer?
The newer BMW models do indeed have adaptive charging and power management systems. Part of this management is monitoring the battery’s capacity and its charge and discharge profiles. When a battery is changed, the power management system needs to be run through a diagnostic cycle in order to properly recognize (register) the different battery and the different capacity, charge and discharge profiles.
If the new battery is not “registered” the vehicle will run and the battery will charge. However, in the long run, the life of the battery will likely be compromised due to improper charging parameters. There are no DIY tools available for your to perform the registering yourself. You will need to see a BMW dealer or an independent shop that has the proper tools to diagnose and program the late model BMWs.