Function of PCBA protection board for 3 series lithium batteries
The BMS protection board of 3S lithium battery pack is the charge and discharge protection for series lithium battery pack. When fully charged, it can ensure that the voltage difference between each single battery cell is less than the set value, realize the equal charge of each single battery of the battery pack, and effectively improve the charging effect under the series charging mode. The main functions of the PCB protection board of 3sereis lithium battery include overcharge protection, over discharge protection, short circuit protection, overcurrent protection, over temperature protection and balance protection.
1. Connect the lithium battery to the protection board according to the wiring diagram
The protection circuit detects the voltage and current of each battery in the series battery pack respectively, and controls the charging and discharging process of the battery pack. When the voltage of each battery in the battery pack is between the overcharge detection voltage and the overdischarge detection voltage, and there is no short circuit in the output, the MOS tube will be turned on, and the battery pack can be discharged through P+ and P-.
2. Battery pack over-discharge protection function
When the voltage of any one battery in the series-connected battery pack drops to the over-discharge detection voltage and reaches the over-discharge delay time, the over-discharge protection function starts, cutting off the discharge MOS tube and prohibiting the battery pack from outputting current to protect the safety of the battery pack, the board enters the hibernation state, the board consumes less than the hibernation current, the circuit into the hibernation state only after connecting the charger and the battery voltage exceeds the over-discharge recovery voltage. Recovery voltage can only be restored.
3. Battery pack overcharge protection function
During the charging process of battery pack through P+ and C-, when the voltage of any battery rises to the battery overcharge detection voltage and exceeds the overcharge delay time, the overcharge protection function starts, cutting off the charging MOS tube and prohibiting the charging of the battery pack to protect the battery pack.
4. Battery pack short circuit protection function
When the battery pack discharge port P+ and P- are short-circuited, the protection circuit will cut off the discharge MOS tube after the short-circuit protection delay time and prohibit the battery pack from external discharge, and the circuit will automatically recover when the external short-circuit is removed.
5. Battery pack overcurrent protection function
When the over-current phenomenon occurs in the battery pack discharge ports P+ and P-, the protection circuit will cut off the discharge MOS tube after the over-current protection delay time and prohibit the battery pack from discharging to the outside, and the circuit will automatically recover when the external short circuit is removed.
6. Temperature protection function
When the temperature of the battery pack is higher than the temperature protection value of 90 degrees Celsius, the charging MOS tube and the discharging MOS tube will be turned off at the same time to prohibit charging and discharging. When the temperature decreases, the temperature protection status will be lifted and the battery pack will be allowed to output current to the outside and charge the battery pack.