BMW's require resetting the battery monitoring system with a new battery, even if it is the exact same spec. They call it Battery Registration.
Most of the people say it affects how the battery is charged and it is important to get full life out of the replacement.
Some of the people say battery registration simply puts an indication into the log noting that it was replaced and does not affect charging at all.
Another big mystery.

I used a handheld scanner/programmer to register the new battery on my BMW. I'm not sure if that option is on my scanner/programmer for my D5.

 

For those of you who purchased Interstate Batteries, keep in mind that they have a warranty that could come in handy over time.