Electric vehicles are the future of transportation technology that is more efficient and environment friendly, especially when it is combined with renewable energy sources. However, the high cost of lithium battery packs is the major limiting factor for more wide market acceptance of electric vehicles.
Currently lithium battery packs costs roughly 50% of the total EV cost. Lithium battery pack consists of hundreds of lithium battery cells and a battery management system (BMS), which monitors each battery cell for safe and efficient operation. It is estimated that that BMS takes about 15% of the battery pack cost.
The goal of this submission is to drastically reduce the BMS cost. We have designed a new BMS architecture using wireless communication technologies between the BMS and battery cell monitoring sensors. Without the sensing wire-harness, the new architecture can address many challenging issues of the conventional wire-based approaches. For example, battery pack design can be simplified and pack manufacturing process can be greatly automated. Battery cell voltage can be measured simultaneously by broadcasting the commands. No isolators are required because the high voltage area is physically separated by the wireless channel.
Consequently, the new architecture reduces the number of BMS components, resulting in fewer failure points for low-cost, highly robust, and reliable battery packs.