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Home >> BMW >> 2017 >> X3 xDrive28d >> Repair and Diagnosis (Single Page) >> General Information >> OEM General Information >> Functional Descriptions - F25 - Charging System, Anti-Theft, Body Electrical Systems >> Body Electrical System - Functional Description >> Power Control Unit (PCU) >> Brief component description >> System battery and auxiliary battery
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System battery and auxiliary battery

Both batteries are installed in the luggage compartment together with the PCU control unit.

The vehicle electrical system battery is an AGM battery with 90 Ah. The auxiliary battery is a 50 Ah AGM battery.

The electrical connections are presented in the functional networking.

Fig 1: Identifying PCU Control Unit And Auxiliary Battery
G09872903Courtesy of BMW OF NORTH AMERICA, INC.
Item Explanation
1 Auxiliary battery
2 PCU control unit
3 System battery