Summarize The Charging And Discharging Process of 18650 Lithium Battery | IMREN Battery

Summarize The Charging And Discharging Process of 18650 Lithium Battery | IMREN Battery

The lithium battery charging control is divided into two stages. The first stage is constant current charging. When the battery voltage is lower than 4.2V, the charger will charge with constant current. The second stage is the constant voltage charging stage. When the battery voltage reaches 4.2V, due to the characteristics of lithium battery, if the voltage is higher, it will be damaged. The charger will fix the voltage at 4.2V, and the charging current will gradually decrease. When the current decreases to a certain value (generally 1/10 set current), the charging circuit will be cut off, the charging completion indicator will be on, and the charging is completed.

Excessive charging and discharging of lithium-ion batteries will cause permanent damage to the positive and negative electrodes. Excessive discharge leads to the collapse of the carbon layer structure of the negative electrode, and the collapse will cause the lithium ion cannot be inserted during the charging process; Over-charging causes too many lithium ions to be embedded in the carbon structure of the negative electrode, and some of them can no longer be released.

Some chargers are implemented by cheap schemes, and are not good enough in control accuracy, which is easy to cause abnormal battery charging and even damage the battery. When purchasing the charger, try to choose the 18650 lithium-ion battery charger of a large brand. The quality and after-sales service are guaranteed to extend the service life of the battery. The 18650 lithium-ion battery charger guaranteed by the brand has four protection functions: short circuit protection, overcurrent protection, overvoltage protection, battery reverse connection protection, etc. Overcharge protection: When the charger overcharges the lithium-ion battery, it is necessary to terminate the charging state in order to prevent the internal pressure rise caused by temperature rise. For this reason, the protection device needs to monitor the battery voltage. When it reaches the battery overcharge voltage, it will activate the overcharge protection function and stop charging. Overdischarge protection: In order to prevent the over-discharge state of the lithium-ion battery, when the voltage of the lithium-ion battery is lower than its over-discharge voltage detection point, the over-discharge protection is activated, the discharge is stopped, and the battery is kept in the standby mode of low static current. Overcurrent and short circuit protection: When the discharge current of lithium ion battery is too large or short circuit occurs, the protection device will activate the overcurrent protection function.

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