What is the function and working principle of the power lithium battery protection board?

2021-09-02 08:49:51 0

Function and working principle of power lithium battery protection board. In recent years, the rapid development of power lithium batteries has made considerable breakthroughs. For the safety and life of lithium batteries, lithium battery protection boards are also indispensable. At the moment, protection boards are also one of the important devices in lithium battery devices. Power lithium battery protection board, it is used to protect the battery from damage and extend the service life of the battery.

Power lithium battery protection board

The power lithium 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 battery protection board function

⒈Overcharge voltage protection: prevent the charging voltage from being higher than the upper limit of the lithium battery's use voltage and causing the battery to fail and cause safety accidents;

⒉Over-discharge voltage protection: prevent deep discharge of power lithium battery, avoid shortening battery life or causing safety accidents

⒊Overcurrent protection: limit the current through the protection board and the battery;

⒋Short circuit protection: avoid safety accidents caused by short circuit of power lithium battery;

⒌Temperature control switch: protect the lithium battery pack and the protection board from overheating and cause safety hazards.

Working principle of power lithium battery protection board

The reason why lithium battery (rechargeable type) needs protection is determined by its own characteristics. Because the material of the lithium battery itself determines that it cannot be overcharged, overdischarged, overcurrent, 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 the power 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 charging and discharging circuit under the environment of -40℃ to +85℃. It can control the on and off of the current loop in time; PTC prevents severe damage to the battery under high temperature environment.

The function of the power lithium 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 battery pack, it is recommended that the battery charging voltage does not exceed 3.6v at any time, that is, the protection voltage of the lithium battery protection board is not higher than 3.6v, the equilibrium voltage is recommended to be 3.4v-3.5v, and the battery discharge protection voltage is generally 2.5v or more. Can.

The lithium battery protection board is a protection for the charging and discharging of the series lithium battery pack; when fully charged, it can ensure that the voltage difference between the individual cells is less than the set value (generally ±20mV), and realize the equal charge of the individual cells 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; undervoltage protection makes every A single-cell battery is used to prevent damage to the battery due to over-discharge.

The power lithium battery protection board has different circuits and parameters according to the use of IC, voltage, etc. The protection board has two core components: a protection IC, which uses an accurate comparator to obtain reliable protection parameters; the other is a MOSFET string Acting as a high-speed switch in the main charging and discharging circuit to perform protection actions.

The above is the introduction of the function and working principle of the power lithium battery protection board. The lithium battery protection board is widely used in mobile phones, walkie-talkies, portable DVDs, miners’ lamps, electric toys, MP3/4 power tools, digital cameras, laptops, special tactical lights, Surveying and mapping equipment, electric bicycles, electric scooters, model airplanes, robots, vacuum cleaners, various field exploration equipment.