The characteristics of lithium batteries and what to pay attention to when discharging the battery

The results indicate that lithium batteries have a high weight to energy ratio and a high volume to energy ratio to voltage. The voltage of a single lithium battery is 3.6V, which is equivalent to the long-term self discharge of three nickel cadmium or nickel hydrogen series rechargeable batteries. This is the outstanding advantage of batteries without memory effect. Lithium batteries do not have the memory effect of nickel cadmium batteries, so under normal working conditions, if the number of charge/discharge cycles exceeds 500, lithium batteries can be quickly charged. Lithium batteries can usually be charged at 0.5-1 times the current, which shortens the charging time to 1-2 hours.

Can be used in parallel freely, because the battery does not contain heavy metal elements such as cadmium, lead, mercury, etc., does not pollute the environment, and is a modern high cost green battery. Compared with other rechargeable batteries, lithium batteries are more expensive.

Precautions for discharging lithium batteries

At the beginning of charging, the voltage of the battery to be charged should be checked first. If the voltage is below 3V, the charging current should be pre charged first, and the charging current should be 1-10 times the set current, usually around 0.05C. When the voltage rises to 3V, it enters the standard charging process. The standard charging process is as follows: constant current charging. When the battery voltage rises to 4.20V, the charging voltage becomes a constant voltage, and the charging voltage is 4.20V. At this point, the charging current gradually decreases, and when the current drops to 1:10 of the set charging current, charging ends.

Usually, lithium battery manufacturers set the charging current between 0.2C and 1C. The higher the current, the faster the charging, and the greater the heat generated by the battery. Moreover, overcurrent charging results in insufficient capacity because the electrochemical reactions inside the battery require time. Just like pouring beer, if it's too fast, it will produce bubbles, but it won't fill up.

Terminology explanation: The charging and discharging current is generally referred to as C, which is the value of the corresponding battery capacity. The battery capacity is usually expressed in Ah and Mah. For example, the battery capacity of m8 is 1200 mAh, corresponding to a C of 1200 mA. 0.2c is equal to 240ma.

Lithium battery discharge, for batteries, the normal use is the discharge process. Lithium battery factory discharge only needs to pay attention to a few points:

1. The discharge current should not be too high, as excessive current can cause internal heating of the battery, which may result in damage; Absolutely not over discharge! Lithium batteries are most afraid of over discharge. Once the discharge voltage is less than 2.7V, it may cause the battery to be scrapped.

From the typical discharge curve, it can be seen that the larger the discharge current, the smaller the discharge capacity, and the faster the voltage drop.

Therefore, under normal circumstances, when the battery load is heavy, voltage recovery occurs when the load decreases, which is known as the "return" phenomenon.