A Battery Management System (BMS) monitors cell voltages, temperatures, and current flow to keep a lithium-ion pack operating within safe boundaries. For EV applications, the BMS must also handle state-of-charge estimation, cell balancing, and communication with the vehicle's main ECU over CAN bus.
Centralized vs. Distributed BMS
In a centralized topology, a single board monitors all cells — simpler and cheaper, but wiring complexity grows with cell count. Distributed (modular) BMS places a slave board on each cell group, communicating with a master via daisy-chain or isoSPI. This topology scales better for 400V+ packs.
Critical Parameters
- Cell count: 4S to 192S (up to 800V nominal)
- Balancing current: Passive 50–200 mA or active 1–5 A
- Measurement accuracy: ±2 mV per cell, ±1 °C temperature
- Communication: CAN 2.0B, CAN FD, or Ethernet
- Functional safety: ASIL-C or ASIL-D per ISO 26262
LAIDNA's BMS & Energy Storage Solutions
We supply BMS boards from 4S to 96S configurations, along with lithium battery modules, solar charge controllers, and DC-DC converters. All sourced from factories with IATF 16949 certification and backed by our engineering validation process.