Components of E38 Dual Battery System
WARNING: This page does not describe the selected car, but rather 208 other vehicles, including the 2010 BMW Z4, 2010 BMW X6 M, 2010 BMW X6, 2010 BMW X5 M, and 2010 BMW X5. However, it is still accessible from the selected car via links, so may be relevant.
- Starter Battery: Located in the right rear trunk wheel, the starter battery is connected to the starter motor and to the heating coils of the E-CATs (via the E-CAT module).
- Vehicle Circuit Battery: Located above the starter battery on a swing out mount, the vehicle circuit battery provides operating power for the balance of the vehicles electrical requirements and is directly connected to the vehicle generator.
- Battery Isolation Switch: Located on the swing out mount of the vehicle circuit battery the battery isolation switch opens and closes the circuit between both batteries based on monitored conditions.
NOTE:
The battery isolation switch is NOT used to boost a discharged starter battery with the voltage of the vehicle circuit battery to start the engine. The battery isolation switch can only withstand a maximum current flow of 60 amps.