Answer: The INRUSH PEAK discharge current and continuous discharge current mainly depend on the battery cell. The overcurrent protection of the protection board only sets a safe discharge current parameter for the battery. If the battery works within this safety parameter, no safety will occur. (but if the discharge current exceeds the load current of the cell allowed, it may also shorten the battery cycle life)
The role of protection circuit board (PCB)
1) Overcharge protection function: Overcharge protection function means that when the battery is charged to a certain voltage, the charger is prohibited from continuing to charge. That is, the overcharged MOS tube is put into an off state to stop charging.
2) Over-discharge protection function: Over-discharge protection function means to stop discharging the load when the battery voltage becomes low. Put the over-discharging MOS tube into the off state to prohibit its discharge.
3) Overcurrent protection function: Overcurrent protection function refers to stopping the discharge of the load when consuming large current. The purpose of this function is to protect the battery and MOS tube to ensure the safety of the battery in the working state.
Therefore, the only function of the PCB is to protect the battery and ensure that the battery can work normally and safely. So, the protection board controls the discharge current of the battery, and the discharge current mainly depends on the cell itself.
Question: What is the difference between 804050 1800mAh 3.7V 2C discharge battery when paired with single MOS tube protection board (3A overcurrent protection) and paired with two MOS tube protection board (6A overcurrent protection):
Answer: First of all, regardless of whether this 1.8Ah 2C discharge battery is equipped with a 3A or 6A overcurrent protection board, the instantaneous maximum discharge current allowed by the cell itself is 6.5A, and the maximum allowable discharge current duration of 6.5A is 20 milliseconds. The maximum continuous discharge current allowed by the cell itself is 3.8-4A (safe range, will not damage the battery).
1. 804050 1.8Ah 2C discharge battery is equipped with single MOS tube protection board (3A overcurrent protection). As mentioned above, the instantaneous discharge current allowed by the 2C cell itself is 6.5A, and the continuous current is 3.8A-4A. But with this 3A overcurrent protection board, the protection board will prevent the battery from discharging when the continuous discharge current of the battery is close to 3A.
Result: With the 3A overcurrent protection board, the 1.8Ah 2C cell cannot be used to the maximum discharge load of the cell itself. The continuous current of the maximum safe discharge of the cell itself can be 3.8A-4A, but with this protection, the pcb believes that the maximum safe load of the battery cell can only be a continuous discharge current of 2A. When the discharge current reaches 3A, it may cause a safety accident, so it prevents the battery from continuing to discharge.
2. 804050 1.8Ah 2C discharge battery is equipped with two MOS tube protection board (6A overcurrent protection). The instantaneous discharge current allowed by the 1.8Ah 2C cell itself is 6.5A, and the continuous current is 3.8A-4A. If it is equipped with 6A overcurrent protection board, then the protection board will think that as long as the continuous discharge current does not exceed 6A, no safety problems will occur, so the 1.8Ah 2C battery can exert its maximum discharge capacity, and there will be no safety problems.
Therefore, in order to allow this 2C battery to discharge safely at maximum load capacity, it is recommended to use a dual MOS tube protection board (6A overcurrent protection).
Question: During the test, the customer found that the continuous discharge current reached 4.7A and the battery was cut off. Is this normal?
Answer: As mentioned above, the maximum continuous discharge current allowed for this battery is 3.8A-4A, then when the current reaches 4.7A during the test, it's seriously exceeded the safe discharge current of the battery (3.8-4A) , it means that 4.7A is already the limit value of the discharge current of the lipo cell itself, so the cell itself has stopped discharging. If the battery is discharged for a long time with 4A-4.7A, it will affect the battery life and even damage the battery.