A battery management system (BMS) is the Capital ‘B’ for brain in batteries. This electronic control system monitors battery and battery pack safety, efficiency, and performance. This feature has become more significant following the outbreak of lithium-ion battery failures. The small circuit board is usually inside the battery case, although it may be independent in multi-battery sets.
Primary Functions of Battery Management ‘Brains’
BMS systems typically monitor the following parameters, to ensure that batteries operate safely for as long as possible:
- Actual voltage to prevent overcharging and overdischarging.
- Prevailing current ratings to detect short circuits or overloads.
- Rising temperatures inside batteries indicating over-heating.
- The state of charge in batteries showing remaining cycle life.
- Overall state of battery health indicating the degree of aging.
We titled this article Capital ‘B’ for Brain in Batteries, because a battery management system does not end there. A BMS stops a dangerous condition in its tracks, by disconnecting an out-of-spec battery when any of those factors are beyond safe limits.
More Features in the Brain of a BMS System
A BMS battery management system also equalizes the cells in a multi-battery pack, to ensure they all have the same voltage level. There are two ways that it may achieve this, depending on the design:
The battery management system may either dissipate any excessive voltage as heat. Or alternatively, it may actively balance the cells by transferring energy from higher-voltage cells to lower-voltage ones.
Other features that make a BMS a Capital ‘B’ for brain in batteries involve maintaining a history log, and perhaps sending status data to an external system in real time. This device may include a battery charger or an electric vehicle control unit, so the user knows the battery status and health as it happens.
More Information
Battery Management System Fundamentals
Battery Management Systems – Inside View
Preview Image: AI Diagram of Battery Management System
