Brief analysis of the working principle of lithium ion battery protection board

The working principle of the lithium-ion battery protection board is introduced. When the battery voltage is between 2.5v and 4.3v, the first and third pins of DW01 both output high level (equal to the power supply voltage), and the second pin voltage is 0V. At this time, add the voltages of the first pin and the third pin of DW01 to the 54th pin of the 8205A respectively. Since the G poles of the two electronic switches in the 8205A receive the voltage of DW01, they are in the on-off state, that is, both electronic switches are in the open state. At this time, the negative electrode of the battery is directly connected to the p terminal of the protection board. The protection function of the protection board with voltage output lithium-ion battery is usually completed by the cooperation of 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 and the current of the charging and discharging circuit at -40°C to +85°C, and control the on and off of the current circuit in time. PTC prevents serious damage to the battery at high temperatures. Overcurrent protection. Due to the chemical characteristics of lithium-ion batteries, battery manufacturers stipulate that the maximum discharge current of lithium-ion batteries cannot exceed 2C (Cu003dbattery capacity/hour). When the discharge current exceeds 2C, there will be permanent battery damage or safety issues. The lithium-ion battery protection board is generally composed of two parts: 1: control IC, 2: MOS switch tube plus some microcapacitors and microresistance control ICs. Protect the battery. If the battery meets the protection conditions, it will control the MOS to turn on or off (if the battery meets the protection conditions such as overcharge, overdischarge, short circuit, overload, etc.), the function of the MOS tube is the switch function, which is controlled by the control IC. The protective plate constitutes a lithium-ion battery (rechargeable) to be protected due to its own characteristics. Because the material of the lithium-ion battery itself determines that it cannot be charged and discharged, overcharged, short-circuited, and charged and discharged at ultra-high temperatures, the battery components of the lithium-ion battery always present a delicate protection board and a current safety device. The protection function of lithium-ion batteries is usually completed by the cooperation of the protection circuit board and the PTC. The protection board is composed of electronic circuits, which can accurately monitor the voltage of the battery and the current of the charging and discharging circuit at any time from -40℃ to +85℃. The battery coverage protection function of the series battery battery voltage drops to the discharge test voltage to realize the discharge delay time , Discharge protection function, start to cut off the discharge MOS tube, prohibit foreign output current and battery pack, battery pack safety protection, the circuit board enters the sleep state, the circuit board sleeps at the current consumption current, and the circuit is connected to the charger after entering the sleep state, and the battery The voltage can only be restored after the voltage is replaced: Some pictures and content of the articles published on this site are from the Internet. If there is any infringement, please contact to delete the previous one: Introduce the safety technology of polymer lithium ion battery operation