Master and Slave BMS

Decentralized BMS Architecture is split into one main controller (master) and multiple slave PCB boards.

Illustration of general decentralized BMS system structure.

Consist of several equal units, which provide the entire functionality locally and autonomously. Each of the individual BMS units is able to operate independently of the remaining ones. Communication lines between the units enable information exchange and task coordination between the units.

Purpose of Master, Slave BMS.

The main master BMS (or battery controller) controls elements such as battery chargers, contractors and external heating or cooling drivers. Battery state algorithms were programmed to calculate the State of charge, State of health, and power capability. In other words, keep the battery operating in the defined safety window.

The slave board is capable of functions such as cell balancing, temperature and voltage monitoring. It receives task messages from the main BMS (master) and periodically sends back cell measurements. The slave board is also called:

  • CSC – Cell Sensor Circuit

In summary, the advantages of decentralized BMS are less wiring costs and highly scalable due to its modular design; while the drawbacks would be requiring more slave PCBs.


  1. Reindl, A., Meier, H., Niemetz, M. (2020), Scalable, Decentralized Battery Management System Based on Self-organizing Nodes, Part of the Lecture Notes in Computer Science book series

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