Lithium batteries should pay attention to five problems

In the process of using lithium ion battery, the following problems should be paid most attention to: overcharge problem, over discharge problem, over current problem, charging imbalance problem and environmental temperature influence battery life, etc. These problems can cause serious damage to the battery, and may even cause the battery to explode. Therefore, lithium ion battery is used to prevent and solve these problems.

1. Overcharging problem

When the voltage of a single cell of a lithium battery exceeds the specified value, the electrolyte in the battery will decompose. The decomposition of electrolyte will increase the temperature of the battery, reduce the service life of the cell, and even cause the explosion of the battery.

Therefore, lithium ion batteries must pay great attention to overcharging in the process of use and research and development, so as to avoid potential safety hazards and resource waste. Protection facilities should be set for the battery during charging. When the voltage exceeds the carrying value of the cell, the set protection circuit should automatically cut off the charging circuit. When the voltage returns to the range that the cell can bear, the protection circuit will automatically stop working and carry out normal charging. Different lithium-ion batteries are made of different materials, so the voltage they can withstand is also different

The circuit should be based on the specific battery material.

In addition, when setting the protection circuit, we should also pay attention to the error judgment and operation caused by noise. When setting the protection circuit, overcharge protection delay should be set, that is to say, the protection of the protection circuit will not be triggered until the voltage exceeds the cell withstand value for a certain time.

2. Over discharge problem

Over discharge problems can also result in shortened battery life. In particular, the damage caused by excessive discharge of lithium ion batteries is irreversible. In other words, once the battery is damaged due to excessive discharge, no measures can be taken to restore the battery to a healthy state. In order to protect the lithium ion battery properly, it is necessary to prevent over discharge and set up discharge protection device. When the voltage of the lithium ion battery is lower than the discharge voltage monitoring point, the discharge protection device can automatically play a role in terminating the discharge process of the battery.

3. Over current, short circuit problem

The problem with over current is that too much current during discharge can also cause damage to the battery, and the damage is also irreversible. Lithium-ion batteries have a limit on the discharge current, and when the discharge current exceeds this critical value, the battery life will be affected.

Over-current protection also need to set up a certain amount of time delay, be in commonly at least hundreds of microseconds to milliseconds, to do so is also to avoid wrong operation on battery process but the delay time is too long, the effect of protection for over current problem is no effect, still can cause the damage to the battery, so the delay time to have a more accurate space. A special performance of the over current problem is the problem of short circuit, life often see such scenes, plug in the socket power electrical appliances, it will be easy to bow I circuit short circuit, which is caused by the large current discharge damage. However, unlike the over current problem, the short circuit problem has almost no problem of protecting the time delay of the circuit. Instead, the circuit should be cut off immediately after the short circuit problem occurs, otherwise it will cause serious losses to the battery and electrical appliances.

4. Battery balance

Power lithium-ion batteries sometimes require several, dozens or even hundreds of strings, and these batteries may be found in the use of unbalanced conditions. This is because the production of batteries needs to go through many procedures. Although they are strictly tested at the end, there will be various differences in the production process. After a period of use, these differences will gradually appear.

In this case, if the battery pack is composed of several batteries, the capacity of the whole battery pack depends on the capacity of the cell of the worst battery pack. This is known as the barrel theory. Faced with such a problem, corresponding protection lines should be set for the battery to extract the excess power from the higher voltage battery, so as to make the battery pack more balanced. There are two common equalization methods: energy storage equalization and resistance equalization.

5. Environmental temperature

For use rechargeable batteries, the influence of environment temperature on the battery life is often ignored by the people, the pool to the specifications of the book have indicate the temperature range of the battery, but under high temperature or low temperature environment, the battery self-discharge rate will be much higher, especially the high temperature will greatly reduce the service life of battery, so before buy, need to try to communicate with engineers, given the use of their equipment or the use of environment, such ability can let the battery performance is better.

The page contains the contents of the machine translation.