Reasons for precharging lithium batteries when charging

For many consumers, it is not clear why lithium batteries should be Pre-Charged first. This is mainly due to the fact that lithium ion batteries have a higher energy ratio. If they enter the fast charging mode directly, they will cause damage to the battery. It affects the useful life and may result in safety hazards.

Lithium battery precharge

Although lithium-ion batteries are currently equipped with line protection panels during the design process, there is usually little chance that the battery will overcharge. However, if the battery is not Pre-Charged at first, it will bring many hidden dangers, such as failure of the protective plate and long-term placement. Self-discharge rate, etc. When the battery is over-discharged, it will cause difficulties in the recovery of the active material. This is necessary to charge it with a small current to 2.5 V to 3.0 V and then convert it into a fast charge. Pre-charge small battery can effectively solve the overdischarge battery charging problem.

When the lithium battery is working, the voltage ranges from 2.5 V to 4.2 V. When the voltage is less than 2.5 V, the battery discharge terminates. At the same time, the current loss of the internal protection circuit is reduced to the lowest because the discharge loop is closed. Of course, due to different internal materials in practical applications, The discharge termination voltage can be in the 2.5 V-3 .0 V range. When the voltage exceeds 4.2 V, the charging loop terminates to protect the battery safety; When the operating voltage of the single battery drops below 3.0 V, we can consider the discharge state and the discharge loop terminates to protect the battery safety.

Some consumers think that the idea of using large currents to charge quickly is a misunderstanding. The larger the charging current, the better. Take the single lithium ion battery. Its charging method includes constant current and constant pressure charging process. The constant pressure is usually 4.2 V, and the constant current setting value is 0.1 C to 1C. Although the charging of a large current will shorten the charging time, it will also cause the battery life cycle to be shortened and the capacity to be reduced. Therefore, experts recommend that consumers must correctly understand the batteries. The importance of precharging, the purpose of the lithium battery in the design process is to increase the pre-charge function, so the newly purchased battery must be Pre-Charged, and the appropriate constant current value is selected to charge the battery.

The page contains the contents of the machine translation.