The balancing principle of lithium battery protection board and the activation method of lithium battery protection board. As we all know, lithium batteries are new energy batteries that are currently used in various fields. However, lithium batteries require protection from protective plates. Many people don’t know that protective plates play a vital role in the use of batteries. Let’s learn about it below. Let’s talk about the activation method of the protective board and its protection principle.

　　Lithium battery protection board

　　The lithium battery protection board is to protect the charge and discharge of the series-connected lithium battery pack; when fully charged, it can ensure that the voltage difference between each single cell is less than the set value (generally ±20mV), achieving even charging of each single cell in the battery pack. , effectively improves the charging effect in series charging mode; simultaneously detects the overvoltage, undervoltage, overcurrent, short circuit, and overtemperature status of each single cell in the battery pack to protect and extend the service life of the battery; undervoltage protection enables each When a single battery is discharged, it can prevent the battery from being damaged due to over-discharge.

　　The finished lithium battery mainly consists of two parts, the lithium battery core and the protective plate. The lithium battery core is mainly composed of positive plate, separator, negative plate, and electrolyte; the positive plate, separator, and negative plate are wound or laminated, packaged, and filled with electrolyte , it is made into a battery core after packaging.

　　Balancing principle of lithium battery protection board

　　Lithium battery protection board balancing principle Commonly used balancing charging technologies include constant shunt resistance balancing charging, on-off shunt resistor balancing charging, average battery voltage balancing charging, switched capacitor balancing charging, buck converter balancing charging, inductor balancing charging, etc.

　　When charging a group of lithium batteries in series, each battery should be charged evenly, otherwise the performance and life of the entire battery group will be affected during use. However, the existing single-cell lithium battery protection chips do not contain the balanced charge control function. The balanced charge control function of the multi-cell lithium battery protection chip requires an external CPU; it is realized through serial communication with the protection chip (such as I2C bus), which increases the This increases the complexity and design difficulty of the protection circuit, reduces the efficiency and reliability of the system, and increases power consumption.

　　The charging overvoltage protection control signal of the single-cell lithium battery protection chip in the control circuit part of the lithium battery pack protection board system is output in parallel after being isolated by an optical coupler to provide the gate voltage for the conduction of the charging switch device in the main circuit; such as a certain cell Or if several lithium batteries enter the overvoltage protection state first during the charging process, the overvoltage protection signal controls the discharge of the shunt discharge branch connected in parallel at the positive and negative ends of the single lithium battery, and at the same time, the corresponding shunt discharge branch connected in series in the charging circuit is discharged. The single lithium battery is disconnected from the charging circuit.

　　Lithium battery protection board activation method

　　The protection function of lithium batteries is usually completed by a protection circuit board and current devices such as PTC. The protection board is composed of electronic circuits and can accurately monitor the voltage and charge return circuit of the battery core at all times in an environment of -40°C to +85°C. Current, timely control the on and off of the current loop; PTC prevents severe damage to the battery in high temperature environments.

　　Now not all lithium battery protection boards need to be activated, but some protection ICs need to be activated, and this is an old IC solution. The old IC solution needs to be done so that the protection board does not work to reduce static electricity. Discharge energy so that lithium batteries can be stored longer. This is why the design requires charge activation.

　　If the lithium battery protection board is under current limiting protection, it may need to be activated by charging or completely disconnecting the load, which is relatively troublesome, but you can also short-circuit B- (battery negative) and P- (discharge negative). Once, the protection will be released. Remember not to carry a large load when short-circuiting and touching it (for example, turning the bar and twisting it all the time), otherwise there may be big sparks. The fundamental reason is that after the protection, a large discharge MOS is formed at both ends. Voltage difference, a short-circuit touch will directly reset the D-S level of the discharge MOS to 0V, and the protection will be released at this moment.

　　How to activate the lithium battery protection board?

　　If the protection board is protected by current limiting, it may need to be activated by charging or completely disconnecting the load, which is relatively troublesome. However, you can also short-circuit B- (battery negative) and P- (discharge negative). The protection will be released. Remember not to carry a large load when the short circuit is touched (such as turning the bar and twisting it all the time), otherwise there may be big sparks. The fundamental reason for this is that a large voltage difference is formed between the two ends of the discharge MOS after protection. , a short-circuit touch will directly reset the D-S level of the discharge MOS to 0V, and the protection will be released at this moment.

Read recommendations:

902030 500mAh 3.7V

Analysis of Lithium iron phosphate industry technology and product status.lithium polymer battery

6LR61 alkaline battery.Why do express delivery companies stop transporting lithium batteries

18650 2000mah battery

CR2032 battery