Thermal management for batteries

Purpose and goal:

The Volvo Group and Carrar initiated a project to deliver and evaluate a high-performance Thermal Management Solution (TMS) for battery packs, and an overall high-power solution for Volvo Group applications. As part of it, Carrar designed and built two battery modules for heavy-duty, long-haul applications that where tested for performance and safety.

Expected results and effects:

In the performance testing, the average temperature variation between the cells was according to the expectations. The temperature uniformity contributes to the cells’ health and can result in longer battery lifetime. In the safety test, the thermal propagation was eliminated as a result of higher heat dissipation than the cell heat generation.

Approach and implementation:

To demonstrate Carrar´s cooling solution, a Proof of Value (PoV) was defined with the Volvo Group. As part of it, Carrar designed and built two battery modules for heavy-duty, long-haul applications. The modules tested for performance and safety.

In the performance test, the module was cycled at room temperature at a pre-defined drive cycle. The safety test consisted of the same module design, in which one cell was triggered by overcharging at 2.7C. Carrar´s thermal management system was completely passive, allowing free flow of refrigerant to the condenser and back to the module.