1. Overcharge Protection and Recovery
1)Single overcharge: When the voltage of any battery cell in the battery pack is higher than the set value of single overcharge voltage and the duration reaches the single overcharge delay, the system enters the state of single overcharge protection, shuts down the charging MOS, and the battery pack cannot continue to charge. After entering the overcharge protection state when the voltage of all cells falls below the recovery value of the overcharge, or when the battery string discharges, the overcharge protection state is removed.
(2)Total voltage overcharge: When the total voltage of the battery pack is greater than the set value of total voltage overcharge protection (default value: number of single overcharge voltage)and the duration reaches the total voltage overcharge delay, the system enters the state of total voltage overcharge protection, shuts down the charging MOS, and the battery pack cannot continue to charge. When the total voltage of the battery string falls below the recovery value of the total voltage overcharge or the battery string discharges, the total voltage overcharge protection state is removed.
2. Overdischarge Protection and Recovery
(1)Single overdischarge: When the minimum voltage of the battery string is lower than the set valueof ss the single overdischarge voltage and the duration reaches the single overdischarge delay,the system enters the overdischarge protection state, shuts down the discharge MOS, and thebattery string cannot continue discharging. After entering the over-discharge protection state, thevoltage of all cells reaches the recovery value of the over-discharge state or the battery string is charged to release the over-discharge protection state.
(2)Total voltage overdischarge: When the total voltage of the battery string is lower than the set value of total voltage overdischarge protection (default value: voltage of a single unit * number of overdischarge) and the duration reaches the total voltage overdischarge delay,the systementers the total voltage overdischarge protection state, shuts down the discharge MOS,and the batterystring cannot continue discharging. When the total voltage of the battery string exceeds the total overvoltage recovery value or the battery string is charged, the total overvoltage protection state isremoved.
3.Charge Overcurrent Protection and Recovery
When the charging current exceeds the charging overcurrent protection current and the duration reaches the overcurrent detection delay time, the system enters the charging overcurrent protecti onstate and the battery pack stops charging. After entering the charging overcurrent protection state,it will automatically recover after 60 seconds or discharge the battery string to release the char ging overcurrent state.
4.Discharge Overcurrent Protection and Recovery
When the discharge current exceeds the discharge overcurrent protection current and the duration reaches the overcurrent detection delay time, the system enters the discharge overcurrent protecti on state and shuts down the discharge MOS. After entering the discharge overcurrent protection st ate, it will automatically recover or charge to remove the discharge overcurrent state after 60 secon ds. Discharge has two stages of overcurrent protection function, has different response speed to dif ferent current values, more reliable protection of the battery.
5.Temperature Protection and Recovery
(1)Charge and discharge high temperature protection and recovery: When the NTC detects that the surface temperature of NTC(MOS) is higher than the set high temperature protection temperature, the system enters the high temperature protection state, the charging or discharging MOSFET is closed, and the battery pack cannot be charged or discharged in this state. When the temperature of the NTC(MOS) surface drops to the set value of high temperature recovery, the system will release the high temperature protection state and the charge and discharge MOS will be turned on again.
(2)Charge and discharge low-temperature protection and recovery: When the temperature of the surface of the core detected by NTC is lower than the set low-temperature protection temperature during charge and discharge, the system enters the low-temperature protection state, andthe charging or discharging MOSFET is off. In this state, the battery pack cannot be charged or discharg ed. When the temperature of NTC surface rises to the set value of low temperature reco very, the sy stem will release the low temperature protection state and the charge and discharge MOS will be tu rned on again.
6.Balancing Function
BMS has passive balancing function and uses resistance discharge to balance. For balance parameters ,please refer to the balance voltage content in “Electrical Characteristics of Protection Board next month. After the balance is started, the balance indicator of the corresponding channel blinks, and the balance indicator stops blinking and goes off. The specific balance is as follows:
Balancing function description | ||||
Detection voltage | equalizing current | Opening Condition | Suspensive Condition | |
Li-ion | ≥4.125±0.03V | 55±15mA | The voltage of any battery > the test voltage Other battery voltages are>the detection voltage | Voltage of all batteries > detection voltage
All battery voltages < test voltage |
LiFePO4 | ≥3.525±0.03V | 47±15mA |
Balancing indicator status description | ||||
State | Flash all at once | Partial Flicker | Stop Flashing | Steady Light |
Explain | Line Connection | The Corresponding Battery is Equalizing | Equalizing off | The Corresponding Resistance
is Burned Out |
3.7Communication
BMS has RS485, UART (reserved), CAN (reserved) communication functions, through the RS485communication interface can communicate with our independent PC, PC can view the real-timestatus information of battery pack, such as SOC, voltage, current, temperature, etc., can adjustthe parameters and function Settings of BMS at any time according to the needs of user environment. Recent history records of BMS protection status can be read and exported. The upper computer supports the online upgrade of BMS and the correction of charging and discharging current. The default baud rate of the upper computer is 115200bps.