14 Li-ion battery management ics for extended battery life and range of electric vehicles

     Renesas Electronics Corporation announced the launch of the fourth-generation lithium-ion (Li-ion) battery management IC that offers high accuracy and lifetime. The ISL78714 provides accurate battery voltage and temperature measurements, battery equalization, and extensive system diagnostics to protect 14 lithium battery packs and maximize battery life and range for hybrid and electric vehicles (HEV/MHEV/PHEV/BEV).

     Masahiro Suzuki, Vice President, Systems Development, Renesas Automotive, said: "The ISL78714 Battery management IC provides the best battery pack monitoring accuracy, fast data acquisition capabilities and fault detection capabilities for battery management systems. We worked with the Mahindra team on Formula E technology and helped them win in the race. We co-designed the lithium-ion battery management system with the ISL78714 IC and RH850 MCU for the Mahindra Electric Racing car."

     The ISL78714 monitors and equalises up to 14 battery cells in series, measuring to ±2 mV over the vehicle's operating temperature range, helping system designers make decisions based on absolute voltage levels. The ISL78714 contains a sophisticated 14-bit analog-to-digital converter and associated data acquisition circuit. The device provides up to six external temperature inputs (two available from GPIO) and includes fault detection and diagnosis for all critical internal functions.

     The ISL78714 meets the safety, reliability and high performance requirements for all types of EV battery pack systems, including HEV/PHEV, enabling automakers to meet the ISO 26262 Automotive Safety Integrity Level (ASIL D) assessment. In addition, the ISL78714 can monitor and read the overvoltage/undervoltage, temperature, open state and fault state of 112 batteries within 10ms; Or monitor and read the status of 70 batteries in 6.5ms.

     Multiple ISL78714s can be connected via a dedicated Daisy chain to support systems with up to 420 cells (30 ics), providing industry-leading transient and EMC/EMI immunity that exceeds automotive class requirements. The ISL78714 Daisy chain topology uses low-cost capacitor or transformer isolation (or a combination of both) to stack multiple battery packs using twisted pair cables while protecting against hot swapping and high voltage transients. When communication with the main MCU is lost, the watchdog timer automatically turns off the Daisy chain IC.