Why do I need a BMS for my lithium battery?
Lithium batteries are very powerful, but their reactions to misuse can be dangerous. Therefore, it is necessary to monitor each electrochemical cell to prevent such cases of unauthorized use.
This monitoring work is carried out thanks to an electronic management card called BMS “Battery Management System”
Lithium cells are very sensitive to their environment: If they are exposed to too severe conditions (voltage, temperature) or if they are subjected to shocks, this can lead to safety problems in the battery.
As the electrolyte is liquid, the risk of short-circuit due to leakage can quickly become dangerous. The liquid reacts with air or water and becomes extremely corrosive.
The critical cases are:
- Exposure to too high or too low temperatures
- Over-discharge followed by recharging
- Short circuit
The consequences of these critical cases are:
- A significant decrease in battery performance
- Decreased battery life
- The risk of fire
The use of a BMS is then essential: it is the guardian of safety to prevent the battery from being exposed to these critical conditions
What a good quality BMS brings you:
- It interrupts the discharge of the cells before it becomes critical for the life of the battery.
- It interrupts the charging of the cells before they are overcharged…
- It optimizes a homogeneous loading from one cell to another
- He’s checking cell temperatures
- It permanently protects the components against overvoltage or undervoltage.
- It prolongs the life of your battery by defining an optimized range of use for electrochemical cells.
- It estimates battery ageing via SOH “State Of Health” and can tell you the number of cycles performed.
- It allows you to know in real time the state of charge of your battery thanks to the SOC “State Of Charge”.
- Via its communication bus, it can control chargers and consumers, such as a motor controller, in order to optimise battery usage and overall system behaviour.
- It can manage several batteries in parallel or in series, to manage more powerful or more capacitive systems.