Every BMW from 2002 onward must have a new battery registered in the power management system (IBS). Without registration the car keeps charging for the old battery's age and chemistry — the new one sulfates within months.

The procedure

  • Connect ISTA and run a full vehicle test first; clear any stored low-voltage faults.
  • Navigate to Vehicle management → Service functions → Power supply → Battery → Register battery replacement.
  • Enter the new battery's capacity (Ah), type (AGM/Flooded) and manufacturer code from the label.
  • Confirm — ISTA writes the replacement record to the DME/DDE in under a minute.
  • Verify: the service menu should show the new registration date and serial.

Swapping battery size? Register with the actual new capacity, not the original — a 90 Ah AGM coded as 70 Ah will never charge fully.