wumk / bms_3-5s

3-5S Battery Management System based on TI bq76920 IC and MSP430 uC.

BMS 3-5S

3-5S Battery Management System based on TI bq76920 IC and MSP430 uC. The design is largely influenced by the TI's TIDA-00449 reference and LibreSolar's excellent BMS-5s designs.

Specs:

• 3-5 Li-ion/Po Cells
• MSP430 Microcontroller for gas gauging, balancing and serial communication
• Load current: 50A (cont.), 100A (peak) (estimated!)
• You can find the PCB on Seeedstudio's Fusion Gallery

Programming

• I'm using MSP430 Launchpad both to program the BMS in external target mode and to provide serial communication to PC.

Demo

• After modifying the TIDA-00449 firmware, which was designed for bq76930 (10S version) balancing and status report worked fine (see here)

To Do in next Rev.

• Add simple Python script to decode serial messages and print cell status
• Fix issues with battery voltage switching and Pre-Discharge mosfets.
• Remove soldermask for high current tracks.
• More pads for balancing resistors for higher power dissipation.

This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.