Lithium power lithium ion battery pack protection board function and wiring

Keywords: constitution function wiring
1. Lithium power lithium ion battery protection board composition
Lithium-powered lithium-ion battery protection board is an integrated circuit board designed for protection of lithium-powered lithium-ion batteries. The protection of lithium-powered lithium-ion batteries is determined by its own characteristics. Since the material of the lithium-power lithium-ion battery itself determines that it cannot be overcharged, over-discharged, over-current, short-circuited, and ultra-high temperature charge and discharge, a protective board will be included when designing the lithium-power lithium-ion battery pack.
Lithium-power lithium-ion battery protection board is usually composed of control IC, switch tube, precision resistors, NTC, PTC, ID memory, etc. The control IC controls the switch tube to conduct when the lithium-power lithium-ion battery pack is all normal, so that the The core communicates with the external circuit, and when the cell voltage, loop current, and temperature exceed the specified value, it immediately (tens of milliseconds) controls the switch tube to turn off to protect the safety of the cell.
NTC is the abbreviation of Negativetemperaturecoefficient, that is, negative temperature coefficient resistance. When the ambient temperature rises, its resistance decreases. ID memory is often a single-wire interface memory. The type of lithium power lithium-ion battery pack, processing date and other information are stored in the ID memory, which can provide traceability and service life information of the product.
PTC is the abbreviation of PositiveTemperatureCoefficient in English. It is a positive temperature coefficient resistor. The PTC in the lithium-powered lithium-ion battery pack product can guard against the occurrence of high-temperature discharge and unsafe large current of the lithium-powered lithium-ion battery pack, based on the voltage, Current density characteristics and use environment have special requirements for PTC. PTC is a very important component in lithium-powered lithium-ion battery pack products, and it bears an important mission for the safety of lithium-powered lithium-ion battery packs. Its performance and quality are also an important factor in the performance and quality of lithium-powered lithium-ion battery packs. .
2. Lithium power lithium ion battery protection board function
The protection of lithium-powered lithium-ion batteries is composed of electronic circuits, which accurately monitor the voltage of the cell, the current of the charging and discharging circuit and the temperature of the cell under the environment of -40℃～+85℃, and control the on and off of the current loop in real time. The design of the protection board for the protection of a single cell will be relatively simple, while the design of the protection board for the protection of the lithium-power lithium-ion battery pack has different design complexity according to different requirements.
There are many factors to consider in the design of lithium-power lithium-ion battery pack protection board, such as voltage platform issues. Li-power lithium-ion battery packs often require a large platform voltage in use, so design lithium-power lithium-ion battery pack protection When installing the board, try to protect the board so that it does not affect the discharge voltage of the cell, so that the requirements for the control IC, sampling resistor and other components will be very high. The current sampling resistor should meet the requirements of high precision, low temperature coefficient, and no inductance. The circuit of the lithium-ion battery protection board is shown in Figure 1. In Figure 1, b+ and b- are the positive and negative terminals of the battery cell; P+ and P- are the positive and negative output of the protection board; T is the temperature resistance (NTC) port. The important functions of the lithium-ion battery protection board are overcharge protection, overdischarge protection, overcurrent protection, short circuit protection, and temperature protection.