Castrol launches innovative electric vehicle (EV) battery e-thermal fluid

Castrol has launched an advanced new ‘ direct' battery e- thermal fluid that will enable future generations of EVs to be charged more rapidly and offer increased performance, protection, and sustainability. Almost all of today's EVs feature batteries using water/ glycol- based coolants contained within a ‘ jacket' that surrounds the battery module. In line with technology demands of the future, the new Castrol ON e- thermal fluid is an innovative dielectric fluid formulated specifically for ‘ direct' cooling, where the fluid circulates within the module and in direct contact with individual battery cells. The result is a significant improvement in thermal management in all operating conditions, at high and low ambient temperatures, for a longer battery life.

The use of Castrol ON e- thermal fluid allows EV batteries to be charged more rapidly. In addition, during discharge the cells remain at their optimum operating temperature maximizing efficiency and performance. In independent tests, during discharge the Castrol ON e- thermal fluid reduced peak cell temperatures by 28° C compared to test water/ glycol coolant, and by 11° C compared to an existing dielectric fluid.

The new Castrol ON e- thermal fluid ensures potential technical problems within the battery module can be better managed. A further benefit of the new Castrol product comes from how it behaves within an EV's coolant circulatory system. It is of a lower viscosity than existing dielectric transformer oils and so delivers reduced pumping losses, optimizing the efficiency and effectiveness of the temperature management process.

“We're undertaking extensive testing of the new direct Castrol ON e- thermal fluid to ensure it provides high levels of performance, protection and sustainability, throughout the life of the battery,” comments Dr Marc Payne, Castrol's EV fluids research manager. “The increased power density that can be enabled through the application of direct battery cooling will allow manufacturers to develop EVs with even greater performance and much improved fast- charging capabilities. While direct e- thermal fluids currently only feature in high- profile hybrid and battery- EV ( BEV) hypercars, we expect the technology to ‘ trickle down' and be widely adopted in future generations of volume- selling EVs.”

The Castrol ON e- thermal fluid is part of a family of Castrol ON products, which include Castrol ON e- Transmission fluids and Castrol ON e- Greases.

Castrol's high- performance e- Mobility team is optimizing thermal management performance through joint coengineering programs with partners.