What is the difference between a Protection board and a BMS?

A protection board and a battery management system (BMS) are both used to protect lithium-ion batteries, but they serve different functions.

A protection board is a small electronic circuit that is typically placed between the battery and the device it powers. It is designed to prevent overcharging, over-discharging, and short circuits. Protection boards are relatively simple and inexpensive, and they are often used in applications where only basic battery protection is needed.

On the other hand, a BMS is a more sophisticated system that manages and protects a battery pack as a whole. A BMS typically includes multiple protection boards, along with additional components such as sensors, controllers, and communication interfaces. A BMS monitors the voltage, temperature, and other parameters of each individual cell in the battery pack and adjusts the charging and discharging rates to ensure that the cells stay within safe limits. It also provides advanced features such as cell balancing, which helps to equalize the charge levels of the cells in the pack to maximize the pack's capacity and lifespan.

In summary, a protection board is a simple circuit that protects a single cell from overcharging, over-discharging, and short circuits, while a BMS is a more advanced system that manages and protects a battery pack as a whole, providing features such as cell balancing and sophisticated monitoring and control capabilities.