Originally Posted by Tom K.
I looked it up and the online '08 manual (with iDrive) says on p. 220 that the electrolyte will last the life of the battery. It says nothing about how long that battery life will be.
Average BMW battery life seems to be around 5 years, but YMMV!
Yep, looked i tup too. you're right - i completely made that up. i guess i remembered wrong.