BMS Communication Guide
The Battery Management System (BMS) is the brain of a lithium pack. Its communication is what turns a dumb battery into a monitored asset.
What the BMS measures and reports
- Cell/pack voltage and balancing status
- Current (charge/discharge) and SoC (state of charge)
- SoH (state of health / remaining life)
- Temperature per sensor, and fault/protect flags
The common transports
- RS485 (Modbus RTU): the workhorse for external monitoring and gateways; master-slave, long cable runs.
- CAN bus: used inside the pack and for fast, robust intra-node messaging.
- SNMP: lets the NOC poll battery data over the network — see the SNMP guide.
- Bluetooth: field commissioning and quick checks from a phone.
What to actually monitor
Track pack voltage, SoC, max cell delta (imbalance), temperature and fault flags. A rising cell delta or falling SoH is your early-warning before a site goes dark. For the transport choice, read CAN vs RS485.