What is the power lithium-ion battery protection board?
What is the power lithium-ion battery protection board
The power lithium-ion battery protection board is a necessary equipment to enhance the safety of the power lithium-ion battery. In most cases, the lithium battery protection board should have the function of controlling the working conditions of the lithium-ion battery. These working conditions include voltage, current, temperature, etc. Due to the particularity of the use of lithium-ion batteries, the power lithium-ion battery must be used together with the protection board to ensure the safety and reliability of the entire system. Power lithium-ion battery protection board: refers to the power equipment, such as motors, energy storage equipment and other systems, the lithium-ion battery management system that supplies energy. The important function is to deal with lithium-ion battery overshoot, overdischarge, overcurrent, and short circuit. Power lithium-ion batteries are protected in groups. Each lithium-ion battery requires protection of over-voltage, under-voltage, over-current, and short-circuit protection. During the charging process, the problem of balanced charging of the entire group of batteries is introduced. A design method for a battery pack protection board with equalizing charging function that uses a single-cell lithium-ion battery protection chip to protect any number of groups of lithium-ion batteries connected in series. The simulation results and industrial production application proved that the protection function of the protection board is perfect, the work is stable, and the cost performance is high.
Working principle of power lithium ion battery protection board
The reason why lithium-ion batteries (rechargeable) need to be protected is determined by their own characteristics. Since the material of the lithium-ion battery itself determines that it cannot be overcharged, over-discharged, over-current, short-circuited, and ultra-high temperature charging and discharging, the lithium battery components will always appear with a delicate protection board and a current fuse.
The protection function of power lithium-ion 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 and charge and discharge of the cell at all times in the environment of -40℃ to +85℃ The current of the loop can be switched on and off in time to control the current loop; PTC prevents severe damage to the battery in a high temperature environment.
The purpose of the power lithium-ion battery protection board is to protect the battery from overcharge, overdischarge and high current damage to the battery, and to balance the battery voltage when fully charged. In order to protect the life of the lithium-ion battery pack, it is recommended that the battery charging voltage not exceed 3.6v at any time, that is, the protection voltage of the lithium-ion battery protection board is not higher than 3.6v, the balanced voltage is recommended 3.4v-3.5v, and the battery discharge protection voltage is generally 2.5v The above will do.
The lithium-ion battery protection board is the charge and discharge protection of the series-connected lithium-ion battery pack; when fully charged, it can ensure that the voltage difference between the individual cells is less than the set value (generally ±20mV), so as to achieve the Equalizing charge 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 cell in the battery pack to protect and extend the battery life; undervoltage protection Make each single battery prevent the battery from being damaged due to over-discharge when it is used for discharging. The power lithium-ion battery protection board has different circuits and parameters depending on the IC, voltage, etc. used. The protection board has two core components: a protection IC, which uses a precise comparator to obtain reliable protection parameters; the other is MOSFET The string acts as a high-speed switch in the main charging and discharging circuit to perform protection actions.