Reference design for a battery management system suitable for high-voltage automotive batteries.
With the advancement in lithium-ion battery technologies, the future is all-electric automobiles. But li-ion cells are vulnerable to catching fire especially while charging, discharging or when the temperature of the battery pack is high. Therefore, it is necessary to employ a battery management system (BMS) to ensure the safety of the battery and the passengers. This reference design can help you build a BMS that can not only enhance the safety of your vehicle but also increase the life of your battery pack.
The BMS reference design from Renesas is based on the ISL78714BMS5XBEKIT1Z automotive-grade multi-cell Li-ion battery manager reference design kit. It is capable of supporting up to 70 series-connected Li-ion cells which makes it suitable for high voltage (HV) battery packs used in EVs. The reference design employs an RH850 microcontroller (MCU) that communicates with the ISL78714 multi-cell Li-ion battery manager devices to monitor cell voltage, pack temperature and current, record significant fault detection, and control cell balance.
This BMS reference design can be daisy-chained to connect multiple modules to support bigger batteries. It contains daisy chain hardware to provide robust, isolated communication between batteries. The RH850 can interface to multiple CAN, LIN, UART, and RS-485 buses and control multiple PWM outputs. In a typical configuration, a Master ISL78714 communicates to a host microcontroller through an SPI port and up to 29 additional ISL78714 devices connected together by a robust, proprietary, two-wire Daisy Chain. This communication system is highly flexible and can be implemented with capacitor isolation, transformer isolation, or a combination of both.
Renesas has tested this reference design. The company has provided more details including schematics, test results, etc. for this reference design to simplify making this reference design. You can find additional data about the reference design on the company’s website. To read more about this reference design click here.