A battery management system is essentially the “brain” of a battery pack; it measures and reports crucial information for the operation of the battery and also also protects the battery from damage in a wide range of operating conditions.



How does it work?
In short, a BMS analyses real-time measurements from the chemical battery, then adjusts charging/discharging parameters and communicates this information to end-users. These sensors can monitor battery voltage, state of charge (SOC), state of health (SOH), temperature and other critical measurements. They can even display charging time on an easy-to-read “fuel gauge.”

What is the main functions of the BMS?
1, The single most important function that a battery management system performs is cell protection.
If the lithium ion battery is charged above a certain threshold or discharged below a certain threshold, the batteries will be damaged, and their capacity can become permanently reduced.
To ensure a battery's charge doesn't go above or below its limits, a battery management system has a safeguard device called a dedicated Lithium-ion protector
Every battery protection circuit has two electronic switches called "MOSFETs." MOSFETs are semiconductors used to switch electronic signals on or off in a circuit.
A battery management system typically has a Discharge MOSFET and a Charge MOSFET.
If the protector detects that the voltage across the cells exceeds a certain limit, it will discontinue the charge by opening the Charge MOSFET chip. Once the charge has gone back down to a safe level then the switch will close again.
Similarly, when a cell drains to a certain voltage, the protector will cut off the discharge by opening the Discharge MOSFET.

2. The second most important function performed by a battery management system is energy management.
A good example of energy management is your laptop battery's power meter. Most laptops today are not only able to tell you how much charge is left in the battery but also what your rate of consumption is and how much time you'll have left to use the device before the battery needs to be recharged. So, in practical terms, energy management is very important in portable electronic devices.
 A battery management system tracks this capacity. This state of charge is communicated to the user electronically through a digital bus called an SM BUS or through a state of charge display where you press a button and an LED display gives you an indication of the total charge in 20% increments.

3. The third is cell balance.
A battery pack usually consists of several individual cells that work together in combination. Ideally, all the cells in a battery pack should be kept at the same state of charge. If the cells go out of balance, individual cells can get stressed and lead to premature charge termination and a reduction in the overall cycle life of the battery. The cell balancers of the battery management system, shown here, extend the life of the battery by preventing this imbalance of charge in individual cells from occurring.

Benefits of the Battery Management System
Safety: Improves safety of high-voltage batteries and decreases the occurrence of thermal runaway and catastrophic failures
Reliability: Utilizes a low pin count, causing reduced complexity and increased reliability
Dual-purpose: Detects the individual bad cells within series and parallel cells
Extended battery life: Manages battery cells within a string, which increases the life of battery systems
Decreased battery damage: Prevents damage from too much or too little voltage
Limited charge current: Balances cells by adding charge to individual cells after main charge is complete
Low cost: Provides a less expensive alternative to existing, commercially available solutions

A battery management system can optimize battery reliability, safety, maintenance, performance and lifespan. So it may be worth considering whether a battery management system could help save time, headaches and money. For more information, Pls contact us.