A lithium-ion battery protection board is a circuit board used for protection. It mainly consists of electronic circuits and accurately monitors the cell voltage and the charging/discharging current in environments ranging from -40℃ to +85℃, controlling the current circuit's continuity in a timely manner.
A typical lithium-ion battery protection board usually includes a control IC, a MOS switch, resistors, capacitors, and some auxiliary components. The control IC controls the MOS switch under normal conditions to connect the battery cell to the external circuit. When the battery cell voltage or circuit current exceeds a specified value, it immediately controls the MOS switch to turn off, protecting the battery cell.
What are the uses of a lithium-ion battery protection board?
A lithium-ion battery protection board provides charge and discharge protection for series and parallel battery packs. It also detects overvoltage, overcurrent, overtemperature, undervoltage, and short-circuit conditions in individual cells, extending battery life and preventing damage from over-discharge. The lithium-ion battery protection board is an indispensable component of lithium-ion batteries.
Lithium-ion battery protection boards also serve a balancing protection purpose, with two methods: energy dissipation balancing and energy conversion balancing. Energy dissipation balancing refers to using a resistor to dissipate excess energy from the battery with the highest charge or voltage in a multi-cell battery pack. Energy dissipation balancing is further divided into charging-time balancing, voltage-fixed-point balancing, and static automatic balancing.
Equalization during charging: When any battery's voltage exceeds the average voltage of all batteries during charging, the protection board activates equalization protection.
Voltage fixed-point equalization: The lithium-ion battery protection board starts equalization at a fixed voltage point, which is only performed at the end of battery charging and has a short equalization time.
Static automatic balancing: This is performed during charging or discharging. Even if the battery is in a static state, the lithium-ion battery protection board will activate balancing protection when the voltage is inconsistent until the voltage is consistent.
Energy transfer involves transferring energy from a large-capacity battery to a small-capacity battery in a storage manner, and then balancing the battery capacity by detecting the capacity. This is divided into real-time capacity balancing and fixed-point capacity balancing.
