BYD Files Patent Application for Battery Cabinet Design
Jakarta (ANTARA) - BYD has filed a patent application for a battery cabinet design that separates electrical components from a lower compartment, where cell modules are immersed in dielectric fluid.
The application, published by the China National Intellectual Property Administration (CNIPA) on 5 October 2026, covers battery cabinets and energy storage equipment, according to a report by CarNewsChina on Tuesday.
The patent application documents, filed in March 2025, describe a container with two chambers within the battery cabinet, where the cooling medium surrounds the battery cell modules while the electrical equipment remains outside the fluid-filled area.
Simply put, whereas older systems cooled batteries from the outside, BYD’s new design immerses the battery modules directly in liquid.
Since electrical equipment must not be submerged, BYD’s design separates it and routes the wiring from the top.
In traditional systems, cooling fluid circulates through aluminium cooling plates placed against the battery module, meaning heat must travel through the cell casing and intermediate materials before reaching the coolant. Immersion cooling changes this configuration. Instead of flowing coolant through separate cooling plates, the battery modules are placed directly into a non-conductive dielectric fluid.
As a result, heat can transfer from the surface of the module in direct contact with the fluid to the surrounding liquid. This configuration shortens the heat transfer path between the battery and the cooling medium, but presents new challenges regarding the protective enclosure.
The fluid must be contained within a vessel, while electrical components and connection points not designed to operate in liquid must remain isolated from it. The boundary between these two areas is the focus of BYD’s battery cabinet design.
The connection between the two chambers is routed through the top of the fluid compartment. Rather than passing power and signal cables through the base or side walls of the wet chamber, BYD’s design directs them upwards before they enter the dry compartment.
Electrical equipment remains outside the fluid volume while maintaining connections to the submerged battery modules. The design relies not only on the dielectric cooling properties of the fluid to separate the battery’s thermal and electrical environments but also utilises the physical layout of the cabinet to keep electrical connection points above the main fluid volume.
BYD’s patent application only covers battery cabinets and energy storage equipment, without mentioning applications for passenger vehicles. A patent application is not proof that the architecture has entered the production stage. BYD has also not yet announced commercial production plans for this design.