How Car Battery Modules Combine High and Low Voltage Systems

A self-contained battery module that houses both high and low voltage batteries, a power converter, and safety switches in a single unit designed for efficient heat management.

What it covers

This patent describes an integrated battery module for vehicles that packs a high-voltage battery (for heavy loads like motors) and a low-voltage battery (for electronics) into one container. It includes a DC-to-DC converter to move power between the two batteries and safety switches that automatically cut power if the container is opened or a service door is accessed. The design also features specific cooling paths and apertures to move heat out of the box, ensuring both the batteries and the converter stay within safe operating temperatures.

What it doesn't cover

• —Does not cover battery systems that lack an integrated DC-to-DC converter.
• —Does not cover systems that rely solely on liquid cooling rather than the described air-flow paths.
• —Does not cover battery modules that do not include a safety disconnect switch triggered by opening the container or a service door.
• —Does not cover standalone batteries that lack a secondary low-voltage battery within the same housing.

The clever bit

The invention treats the entire battery module as a single, modular unit that includes its own safety interlocks and thermal management, rather than treating the battery, converter, and cooling system as separate, scattered components in the car chassis.

Why it matters

This patent addressed the early engineering challenges of transitioning to hybrid and electric vehicles, where managing two different voltage levels in a compact, safe space was difficult. By integrating the converter and safety disconnects into a single module, it helped standardize how manufacturers could package power systems for better reliability and easier maintenance.

Real-world examples

• 1.Early 42V/12V hybrid vehicle electrical architectures
• 2.Integrated battery management units in modern hybrid electric vehicles
• 3.Modular automotive power distribution systems