A battery management system (BMS) is an essential component of any lithium-ion battery system, as it is responsible for maintaining the cells in the battery pack healthy and working at their best.
Every battery has a voltage, current, and temperature range within which it can work safely. If one or more of these parameters deviates significantly from the recommended range, your battery pack may be permanently damaged (due to component degradation) and may even represent a safety issue. To prevent this from happening, most batteries have a built-in BMS.
How can a BMS keep your battery pack from being damaged
The discharge and charge processes of LiFePO4 battery packs are controlled by a LiFePO4 BMS. So, if something goes wrong during these procedures, the BMS protection kicks in and either modifies the charging settings or completely shuts down the power flowing to and from the battery pack.
A BMS also keeps track of the battery cells and ensures that they’re all performing properly. It also monitors voltage, current, and temperature to ensure that the battery is in good working order. In this way, a BMS can help your battery avoid: Overcharge, Overvoltage, Cell Imbalance Due to Overcurrent and Overtemperature, Life cycle is shorter.
A BMS also optimizes the capacity and general performance of your battery during every charge/discharge cycle. You’ll be able to get the most out of your LiFePO4 battery pack in terms of performance and lifespan this way.
How Does BMS Work
A LiFePO4 BMS is made up of many hardware and software functional blocks with functionalities that monitor and manage the charge and discharge conditions of the battery pack.
A good BMS should provide protection from the following: Voltage imbalances (over- and under-voltage); Imbalance of Cells in the Overcurrent and Undercurrent; Temperatures that are above and below normal; Voltage And Current Cut-off. To maintain these functions:
The cut-off transistors is required. Current- and voltage-driven cut-off transistors in battery management systems can switch off power from the charger to the battery or from the battery to the load. These transistors serve as switches, turning off when the cell voltage monitor detects a voltage higher than the system can manage, protecting the battery from overvoltage.
The Cell Equalization Module is required. Individual cells are theoretically selected with care to ensure that they are all consistent. Despite the fact that the voltage, current, internal resistance, and other parameters are identical at the manufacturer, there will be some changes after a period of cycle use. If left to their own devices, these minor variations will get more and larger with each charge and discharge cycle. Take, for example, the voltage. If one cell is full after a charge cycle while another is not, one cell will be overcharged while the other will be undercharged. These disparities will not rise with the Battery Cell Equalization Module, but will remain the same – a slight change. As a result, the Cell Equalization Module is required. When one cell voltage is 10mV greater than another, the battery cell equalization module sends a tiny current from the higher voltage cell to the lower voltage cell until the two cells’ voltages equalize.
It is crucial to the LiFePO4 battery pack’s longevity.