Advanced Onboard Battery Diagnostics. Starting with the introduction of the F10 (5 Series), an advanced intelligent battery sensor has been used. This now makes it possible for the vehicle to monitor the condition of the battery in order to determine if the battery needs to be recharged or replaced, along with the remaining capacity of the battery. The analysis and testing of the battery's SoC (Stateof Charge) and SoH (State of Health) is now performed using ISTA (Integrated Service Technical Application) diagnosis. A separate test using a battery tester is no longer needed.