LEMON Manuals: Even more car manuals for everyone
Home >> BMW >> 2021 >> 840i 2D Convertible >> Repair and Diagnosis >> External Pages >> Different car >> Section 191 (General Orphan Data (1 Of 2)) >> Activating the 48 V electrical system

Activating the 48 V electrical system

WARNING: This page does not describe the selected car, but rather 7 other vehicles, including the 2025 BMW X4, 2024 BMW X4, 2023 BMW X4, 2022 BMW X4, and 2021 BMW X4. However, it is still accessible from the selected car via links, so may be relevant.

Precondition 

Ignition is switched off.

NOTE: RISK OF DAMAGE 
Damage to the 48-V battery 
If a 48-V battery disconnected from the on-board electrical system is activated, the battery electronics are damaged. 
  • Only ever activate the 48 V electrical system when the 48 V battery is fully connected up.
TIGHTENING TORQUES SPECIFICATION

Negative battery cable to 48-V battery
Nut M8 Tightening torque  19 Nm
G16028027Courtesy of BMW OF NORTH AMERICA, INC.
G16028029Courtesy of BMW OF NORTH AMERICA, INC.