Multi-Cell Battery Monitors Augment Protection For 12- To 48-V Industrial Li-Ions
The scalable bq76920, bq76930, and bq76940 battery monitors protect and control 3- to 15-ell batteries when charging or operating in harsh environment conditions. The circuits, developed by Texas Instruments, improve battery pack safety and help reduce design time of 12- to 48-V lithium-ion and lithium-iron phosphate batteries used in e-bikes, power tools, and energy-storage systems. They measure cell voltages, temperature, and pack current to determine remaining battery capacity and battery state-of-health. Cell-balancing drivers, regulated output supplies, and other features reduce external component count and enhance overvoltage, undervoltage, and overcurrent protection. The bq76920 (packaged in a 20-pin, 4.4- by 6.5-mm TSSOP) supports 3- to 5-series cells or typical 18-V packs; the bq76930 (in a 30-pin, 4.4- by 7.8-mm TSSOP) manages up to 10-series cells or 36-V packs; and the bq76940 (in a 44-pin, 4.4- by 11.3mm TSSOP) monitors up to 15 cells or typical 48-V batteries.