A Battery Management System (BMS) is an electronic system responsible for overseeing safe and efficient operation of rechargeable battery packs. Whether in electric vehicles (EVs), consumer electronics, or industrial applications, the BMS plays a critical role in monitoring and managing various aspects of the battery to ensure its optimal performance, safety, and longevity.

In a typical BMS for electric motorbikes as illustrated in Fig 1, the BMS collects the state of charge (SOC) of the battery pack, analyses the loading and subsequently exchanges the key information with the relevant sub-systems outside of the battery pack. During operation, BMS has to monitor each battery cell in real time, making sure a uniform state of charge is achieved among all cells within a battery pack, thereby maximizing the battery's capacity and its lifespan, and safeguarding against hazardous situations. This task is usually achieved with dedicated cell supervisor and balancing circuit, which determines if any of the cells is to be shut down, or be re-charged at a specific rate, or continue to release its stored energy at a specific rate. The fuel gauge block keeps track of the charge entering and exiting the battery pack, allowing user be updated with accurate estimates of battery charge level in real time. At the heart of this BMS is a MCU, which takes information from the cell supervisor and balancing unit, the fuel gauge and some sensors such as temperature sensor and current sensor, controls charging and discharging, and handles communication functions with external devices such as controllers, chargers, etc.

In electric bikes and motorbikes application, the BMS is a critical component that affects the system's cost, performance, and reliability. For this application, JJM offers wide portfolio of advanced SGT MOSFETs with outstanding electrical and thermal properties, both in industry and automotive grade. Features and benefits include:
●Excellent Rds(on) as low as 1.3mΩ (Typical value)
●Improved avalanche energy to withstand battery short circuit test
●Narrow Vth tolerance ensuring easy parallel use
●Excellent cost performance ratio
●Available voltage rating: 80V, 100V, 110V, 120V, 150V and 200V
●Available in mainstream packages such as TOLL, TO263-3L, as well as TO263-7L

Apart from MOSFETs, JJM also offers wide portfolio of Zener diodes, and surge protection devices such as TVS and ESD diodes for implementing a reliable and cost effective BMS system.