Second battery 50Ah coding and registering

[Qsilver7]

Originally Posted by uteemba

Hi Everyone,

Thank you all for posting your experience and advice on this issue. I wanted to report that I successfully replaced the auxillary battery on my 2017 X5e using the LN1AGM battery ordered from RockAuto (without needing to register the battery), and it completed fixed the Max eDrive issue. It now drives in pure electric mode just fine. Just wanted to pass that along for the next person who encounters the same issue!

..and thank you for keeping this thread updated and relevant.

[nicke_1]

Originally Posted by c00lbeans

Anyone have directions for replacing the Aux battery in a 40e?

I got the fault code 2228C8 in ISTA+ - "Starter unit, auxiliary battery: Aged auxiliary battery". The car is an 40e 2016/03 - eight years battery life is more than one could wish for.
As a replacement I bought a Banner 50Ah 540CCA AGM battery with the correct dimensions (210mm x 175mm x 190mm). Denenergized the high voltage battery according to the instructions in this thread/TIS.


Then did the registration of the new battery in ISTA+ Path: Service functions > Body > Voltage supply > Hybrid car > Starter unit


There is no options available when registring the aux battery, so choose a battery as close to the OEM specs (50Ah 570CCA AGM) as possible.