The difference between lithium battery with protection board and without protection board. When it comes to lithium batteries, they are often connected to the battery management system BMS. The function of the lithium battery protection board is mainly to protect the cells of the rechargeable battery, maintain the safety and stability during the charging and discharging of the battery, and play a role in the performance of the entire battery circuit system. Important role. The main function of the lithium battery protection board is to prevent the overcharge and overdischarge of the lithium battery.

The protection function of lithium battery is usually completed by the protection circuit board and current devices such as PTC or TCO. The protection board is composed of electronic circuits, which can accurately monitor the voltage and charge and discharge of the cell at all times in the environment of -40℃ to +85℃ The current of the loop can instantly control the on and off of the current loop; PTC or TCO can prevent severe damage to the battery in a high temperature environment.

Lithium battery protection board usually includes control IC, MOS switch, JEPSUN precision resistor and auxiliary device NTC, ID memory, PCB, etc. Among them, the control IC controls the MOS switch to turn on under all normal conditions, so that the cell can communicate with the external circuit, and when the cell voltage or loop current exceeds the specified value, it immediately controls the MOS switch to turn off to protect the safety of the cell .

The difference between lithium battery with protection board and without protection board

The lithium battery has a protective plate, which can control the lithium battery cell to work in the specified working environment without explosion or combustion; the lithium battery without the protective plate is prone to explosion, burning and other phenomena. The battery with the protection board can be protected at 4.125V for charging protection voltage, 2.4V for discharge protection, and the charging current can be within the maximum range of the lithium battery; the battery without protection board will be overcharged and overdischarged , Overcurrent, the battery is easily damaged.

The size of the 18650 lithium battery without the protective plate is shorter than the battery with the protective plate, and some devices cannot use the battery with the protective plate due to the initial design. Without the protection board, the cost is low, and the price is relatively cheaper. Lithium battery without protection board is suitable for experienced use, generally do not over-discharge and overcharge, the service life is similar to that with protection board.

The difference between 18650 lithium battery with battery protection board and without protection board is as follows:

1. The battery core without a board is 65mm in height, and the battery with a board is 69-71mm.

2. Discharge to 20V. If the battery reaches 2.4V, it will not discharge, indicating that there is a protection board.

3. Touch the positive and negative levels. If there is no response from the battery after 10 seconds, it means there is a protective plate. If the battery is hot, there is no protective plate.

Why add a lithium battery protection board?

Because the working environment of the lithium battery has special requirements, it cannot be overcharged, overdischarged, overheated, and overcurrent charged and discharged. If it does, it will explode, burn, etc., the battery will be broken, and it will also cause a fire. And other serious social problems. The function of the lithium battery protection board is mainly to protect the cells of the rechargeable battery, maintain the safety and stability of the battery during the charging and discharging process, and play an important role in the performance of the entire lithium battery circuit system.

The lithium battery plus the protection board is determined by the characteristics of the lithium battery. Lithium battery has its safe discharge charge and overcurrent limit. The protection board is added so that these values do not exceed the safety range when using lithium batteries. Lithium batteries have limited requirements during charging and discharging. Take the famous lithium iron phosphate battery as an example: charging generally cannot exceed 3.9V, and discharge cannot be lower than 2V. Otherwise, the battery will be damaged due to overcharging or overdischarging, and this damage is sometimes irrecoverable.

Usually, after the lithium battery is added with a protection board, the voltage of the battery will be controlled within this voltage, which plays a role in protecting the lithium battery. The lithium battery protection board realizes the equal charge of each single cell of the battery pack, which effectively improves the charging effect in the series charging mode. At the same time, it detects the overvoltage, undervoltage, overcurrent, short circuit, and overtemperature status of each single battery in the battery pack to protect and extend the battery life. Under-voltage protection prevents each single cell battery from being damaged due to over-discharge during discharge.

The lithium battery protection board is to control the lithium battery to be protected under normal working conditions. The lithium battery can be overcharged at 3.9-4.3v, the over-discharge protection can be set at 2.3-2.6V, and the overcurrent can be done according to the battery requirements. Can also be controlled. It can be seen that the lithium battery protection board is a necessary condition for the lithium battery to work in a normal environment and not to make the lithium battery product dangerous.

So far, there has not been a lithium battery manufacturer that publicly declares not to use the protection board. Lithium batteries generally have protective plates, and the use of protective plates is also for battery safety. But different types of battery protection boards have different functions.