The battery info is stored in the CAS module. When our '13 E70 CAS module got fried and had to be changed out by the $tealership they, of course, had to program the new module to the vehicle. They coded the battery as a 105AH AGM but did not code in the date code so it shows 00/00/00. As the I_BS system is supposed to vary the charge depending on the age and type of battery you have to wonder just how good it actually is in reality.
For $250 a coding session I think I'll be sticking in a nice big $200 locally supplied battery every 6 years when the first symptoms appear of a failing battery.
The E53 charging system was good enough. I put in an Exide battery back in Nov 2004 that lasted until 2015. Local tire place put in one of their super specials that just got changed out a couple of months ago.
What has happened to modern batteries? You could find 96 month warranty batteries everywhere in the 80's. Even K-Mart!!. Now you are lucky if the warranty is a prorated 36 months.

__________________
Sent via Telegraph Wires using my Morse Key.
2021 X5 xDrive40i
2015 X5 xDrive35i MSport
(Traded) 2013 X5 xDrive35i