4s 20A BMS For LiFePo4 With Balancing 12.8V

4S 20A BMS for LiFePO4 with Balancing (12.8V) – Description

A 4S 20A BMS (Battery Management System) designed for LiFePO4 (Lithium Iron Phosphate) cells is an essential component for managing and protecting a 12.8V lithium iron phosphate battery pack, specifically with a 4-series (4S) configuration. LiFePO4 batteries are known for their safety, long cycle life, and stability, making them an excellent choice for energy storage and electric vehicle applications.

This BMS ensures the safe operation of the battery pack by monitoring and protecting the cells from overcharging, overdischarging, overcurrent, and thermal runaway. It also features cell balancing, which helps maintain the health and longevity of the battery pack.

Key Features:

1. 4S Configuration (4 Cells in Series):
   • The BMS is designed for a 4-cell LiFePO4 pack in series. Each LiFePO4 cell has a nominal voltage of 3.2V, resulting in a nominal pack voltage of 12.8V (3.2V x 4 cells).
   • The fully charged voltage for the 4S LiFePO4 pack is 14.6V (3.65V x 4 cells), which is within the safe charging range for LiFePO4 batteries.
2. Current Rating – 20A:
   • The BMS supports a continuous discharge current of 20A, which is sufficient for a variety of moderate-power applications, such as electric vehicles (e-bikes, scooters), energy storage systems, and portable power banks.
   • The BMS may also support a peak current (short duration) higher than 20A (usually up to 40A) for brief surges.
3. Overvoltage Protection:
   • The BMS monitors the voltage of each individual cell and provides overvoltage protection by disconnecting the charger if any cell exceeds its maximum safe voltage (typically 3.65V per cell).
   • This prevents the battery from being overcharged, which could cause overheating, swelling, or damage to the cells.
4. Undervoltage Protection:
   • The BMS ensures that no cell is discharged below its minimum safe voltage (typically around 2.5V to 2.8V per cell). If any cell drops below this threshold, the BMS disconnects the load to prevent deep discharge, which could result in capacity loss or permanent damage to the cells.
5. Overcurrent Protection:
   • The overcurrent protection feature ensures that the current drawn from the battery does not exceed the BMS’s rated discharge current (20A). If the current exceeds this limit, the BMS will cut off the load to prevent overheating or other potential damage to the battery cells.
6. Short Circuit Protection:
   • In the event of a short circuit in the wiring or load, the BMS will disconnect the battery pack immediately to prevent any further damage or risks associated with short-circuiting, such as fire or component failure.
7. Overtemperature Protection:
   • The BMS includes overtemperature protection to monitor the temperature of the battery pack. If the temperature rises above a safe threshold (typically 60°C to 70°C), the BMS will disconnect the load or charging process to prevent thermal runaway, overheating, or fire.
8. Cell Balancing:
   • Cell balancing is an important feature for maintaining the health of the battery pack. The BMS ensures that the voltages of all four cells in the pack remain balanced (i.e., each cell is charged and discharged evenly).
   • Passive Balancing: In this case, excess energy from higher-voltage cells is dissipated as heat to equalize the voltages of the cells, preventing imbalance that could lead to uneven wear and shorter lifespan.
9. MOSFET Protection:
   • The BMS utilizes MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors) for efficient switching of current between the battery pack and the load/charger. These MOSFETs allow th