Types of BMS

There are several main types of BMS, with functional safety and Battery Pack performance being important features:

Centralized BMS architecture: There is a central BMS in the battery pack assembly, and all battery packs are directly connected. The advantages are compactness and economy; the disadvantages are that large battery packs have many connection ports, complicated wires, etc., and complex troubleshooting and maintenance.

Modular BMS topology: The BMS is divided into repeated modules, each module connects to a specified part of the battery pack, and some sub-modules are supervised by the main module. The advantage is that troubleshooting, maintenance and expansion are convenient; the disadvantage is that the cost is slightly higher and there may be repeated unused functions.

Master/Slave BMS: The concept is similar to modular topology, where the slave device relays the measurement information and the master device is responsible for calculation, control and external communication. The cost may be lower because the slave device has simple functions and few unused functions.

Distributed BMS architecture: The electronic hardware is integrated on the control board of the monitored battery or module, simplifying the wiring. Each BMS is more independent and responsible for calculation and communication. The disadvantage is that troubleshooting and maintenance are difficult and costly.

Functional safety: Prevent the voltage, current, and temperature of the battery or module from exceeding the SOA limit during charging and discharging to avoid battery damage and thermal runaway; monitor low voltage thresholds to prevent safety issues caused by the growth of copper dendrites in lithium-ion batteries.

Battery Pack Performance:

Electrical management: Balance all cells in the battery pack to make adjacent cells have roughly the same SOC, optimize overall battery capacity, prevent performance degradation and potential hot spots, and avoid over-discharge of lithium-ion batteries.

Thermal management: Temperature affects battery performance. BMS starts heating equipment to increase the battery temperature at low temperatures to ensure that it operates within the optimal temperature range (such as 30-35°C) to ensure performance and extend life.