In most BMW 4 Series models, the 12-volt battery sits in the trunk rather than under the hood. For plug-in hybrids and some newer variants, you’ll also encounter a high-voltage battery whose location varies. This article explains where to find the batteries across common 4 Series generations and what to expect when you need access for maintenance or jump-starts.
12-volt battery location in traditional gasoline/diesel 4 Series
The 12-volt battery in most non-hybrid 4 Series models is located in the trunk. It is typically mounted on the passenger side behind an access panel or trim, with the main fuse/relay box nearby. Access usually requires removing a section of the carpet or lifting a part of the trunk floor.
- F32/F33/F36 generation (roughly 2013–2020): 12V battery is in the trunk, commonly on the passenger side behind trim; floor panels or carpeting provide access to the battery and its fuses.
- G22/G23 generation (2020–present) and related body styles: 12V battery remains in the trunk, though the exact mounting can vary by model year; many layouts use the trunk floor or a side panel for access.
In all cases, the 12V battery is not located in the engine bay. If you’re planning a jump-start or battery replacement, consult the owner’s manual for the exact panel to remove and follow safety precautions.
Plug-in hybrid 4 Series battery locations
Plug-in hybrid variants such as the 430e/440e add a high-voltage (HV) battery to power the electric motor. To preserve trunk space and maintain weight distribution, BMW typically places the HV pack toward the rear of the car, with various layouts by generation and market. The high-voltage battery is separate from the standard 12V battery and requires different safety handling during service.
Possible HV battery layouts in plug-in hybrids
- Generation-specific layouts (hybrid 4 Series): The HV battery is usually mounted under the rear seat floor or within the trunk floor structure. Access for charging ports and service panels varies by year and model.
- Modern plug-in hybrids: The HV pack location is designed to minimize impact on trunk volume; you may notice a slight reduction in cargo space or a reshaped floor panel to accommodate the battery.
Because HV battery placement can change with generation and regional specifications, always refer to the owner's manual or BMW service documentation for the exact location and safety guidelines when servicing or disconnecting high-voltage systems.
Summary
For most BMW 4 Series models, the standard 12-volt battery lives in the trunk, away from the engine bay, with placement that varies slightly by generation. In plug-in hybrids, a high-voltage battery powers the electric drive and is typically mounted under the rear seat floor or in the trunk floor to preserve cargo space. Always check the specific model year guidance in the owner's manual for precise location and safety procedures when performing maintenance or jump-starts.