Yes. The coding needs to be changed so that the DME will accommodate the charging of a lesser amp hour battery. If any parameters of the battery changes...then the charging system needs to be recoded so that the system will adjust accordingly to those changes.
- Register ALL new battery replacements.
- Recode parameters if the battery specs change
Here's a link to a very comprehensive thread that goes into details about registering/coding BMW batteries:
https://www.e90post.com/forums/showthread.php?t=1338302