There's been a lot of disussion on this. The issue is two fold- the car needs to know the battery capacity and overall specs...AND the system needs to know where the battery is in terms of it's specific lifecycle. Over time batteries degrade and their charge characteristics change-and the BMW system takes this into account (why, and if this added complexity is justified, is an unanswered question) so even wen you just replace the old with new, you need to 'tell' the car there is a new one installed. If you change the overall battery type or capacity, that also needs to be programmed.

I beleive it is called 'coding' if you change battery type or capacity, and 'registration' if you just replace the battery.

I am of two minds- under warranty, or when you are paying $140 an hour, we dot Is and cross Ts. They need to do everything properly and when they don't they pay the price- after all, they justify the fee with "we are the dealer and stand behind our work" (The whole "we charge book time, which is always less than actual, to make up for the times it cost more or takes longer".)

AFTER the warranty, screw it- put in a fresh battery, skip the registration. Even if you get 1/2 the life, the $200 saved by not going to the dealer buys the new battery next time.

AND, I am 99.999% certain you will be able to do this yourself once these warranties begin to expire and there is a market for 'battery reset widgets'

A