What are the requirements for charging and discharging lithium batteries?

What are the requirements for charging and discharging lithium batteries and the protection circuit?Lithium batteries have a great impact in the battery industry. The industry has been paying attention to the mature technology of lithium batteries in recent years. It is widely used in the new energy automobile industry to replace the nickel-hydrogen battery industry and win new The milestone, don’t activate it. It has no memory effect and can reach more than 500 times of charging and discharging. It is a green high-performance product. When charging a lithium battery, according to the structure and characteristics of the lithium battery, the end-of-charge voltage is up to 4.2v and cannot be overcharged, otherwise the battery will be scrapped due to excessive lithium ions in the positive electrode. It has high charging and discharging requirements and can be charged with a dedicated constant current and constant voltage charger. Under normal circumstances, constant current charging is switched to constant voltage charging after 4.2v/node charging. When the constant voltage charging current is lower than 100mA, the charging should be stopped. The traditional charging current can be about 0.5 times the battery capacity, and the charging time is about 2-3 hours. The discharge of a lithium battery is caused by the internal structure of the lithium battery. Lithium ions cannot all move to the positive electrode during discharge, and some lithium ions must be kept at the negative electrode to ensure that lithium ions can be inserted into the channel smoothly during the next charge. Otherwise, the battery life will be shortened accordingly. In order to ensure that some lithium ions remain in the graphite layer after discharge, it is necessary to strictly limit the minimum voltage at which the discharge is terminated, that is, the lithium battery cannot be over-discharged. The discharge termination voltage is generally 3.0V/node, and the minimum should not be less than 2.5V/node. The battery discharge time is related to the battery capacity and discharge current. At present, the charging and discharging protection circuit of lithium batteries on the market is mainly composed of two field effect transistors and a special protection integrated block S8232. The charge control tube FET2 and discharge control FET1 series circuits control the protection integrated circuit and monitor the battery voltage. 4.2V, deadline, stop charging, charge protection tube FET1 in order to prevent misoperation, generally delay the battery capacity in the external circuit, when the battery is discharged, when the battery voltage is 2.55V, the discharge control tube FET1 cuts off and stops supplying power to the load. Overcurrent protection is to control the load and stop unloading of the load when the large current flows through the FET1 to protect the battery effect tube. The lithium battery pack is equipped with a protection board to prevent battery charging and discharging and flow. You can use the FET on-resistance to test the resistance, monitor its voltage drop, and generally add a delay circuit circuit. In order to distinguish between impulse current and short-circuit current, the circuit function, Reliable performance and strong specialization are the mainstream products in the current market. Disclaimer: Some pictures and content of articles published on this site are from the Internet. If there is any infringement, please contact to delete. Previous: Should I choose lead-acid batteries or lithium batteries for electric vehicle batteries?