What are the common faults of the lithium battery pack protection board?

What are the common faults of the lithium battery pack protection board?

Lithium battery protection board maintenance methods and common faults. The damage to the lithium battery protection board depends on the extent of the damage and the value of the repair. Lithium battery protection board, as the name suggests, is used to protect lithium batteries. The role of the lithium battery protection board is to protect the battery from over-discharge, over-charge, and over-current, and also protect the output from short circuits. How to repair the damaged lithium battery protection board?

If the protection board of the lithium battery is broken, you can charge it with a charger first to see if the protection board can be activated. If you can't fill it, it must be broken. It may be that the electronic components are damaged, or it may have just been reset! But if the protection board is broken, the measured value should be 0V. If you have been in contact with the lithium battery protection board, let’s discuss why the lithium battery protection board does not have charge and discharge protection and hope to bring you some useful help.

Under what circumstances does the lithium battery protection board have no charge and discharge protection?

First look at the ternary parameters: iron and lithium are 2.8 ~ 4.25 and 2.5 ~ 3.65 V, respectively.

1. It may be voltage overcharge, overdischarge, overcurrent, short circuit, or over-temperature.

2. Use a multimeter to measure whether the charging and discharging MOS tube is open.

3. If the lithium battery protection board is equipped with an LED when it cannot be charged or discharged, the LED will flash for 0.5 seconds to give an alarm.

4. If the lithium battery protection board is equipped with a host computer, you can connect to the host computer to check the protection status.

5. The lithium battery protection board is equipped with a weak point switch, please check whether the weak point switch is turned on.

In these cases, you can fix it by:

1. Overcharge, over-discharge, over-current, short-circuit plug into the charger for recycling.

2. Load recovery after over-current disconnection

What is a lithium battery protection board?

The lithium battery protection board is charge-discharge protection for a series of lithium battery packs; after fully charged, it can ensure that the voltage difference between the single cells is less than the set value so that all the single cells in the battery pack are charged evenly, effectively improving the series charging mode Under the charging effect. Simultaneously detect the overvoltage, undervoltage, overcurrent, short circuit, and overtemperature status of every single battery in the battery pack to protect and prolong the service life of the battery; undervoltage protection prevents every single battery from being damaged due to Damage the battery due to over-discharge.

Lithium battery protection board principle: The reason why lithium batteries (rechargeable) need protection is determined by their own characteristics. Due to the material of the lithium battery itself, it cannot be overcharged, over-discharged, over-current, short-circuited, and charged and discharged at ultra-high temperatures, so there will always be a delicate protection board and a current fuse in the lithium battery assembly.

The protection function of the lithium battery is usually completed by the protection circuit board and current devices such as PTC. The protection board is composed of electronic circuits, which can accurately monitor the voltage of the battery cell and the current of the charging and discharging circuit at any time in the environment of -40 to 85, and control the on-off of the current circuit in time. PTC prevents the battery from being severely damaged in high-temperature environments.

Common lithium battery protection boards usually include control ICs, MOS switches, resistors, capacitors and auxiliary device fuses, PTC, NTC, ID, memory, etc. Among them, the control IC controls the conduction of the MOS switch under all normal conditions to connect the cell to the external circuit. When the cell voltage or loop current exceeds the specified value, the control IC immediately controls the MOS switch to turn off to protect the safety of the cell.