Precautions for charging lithium batteries:
1. When charging the lithium battery, it is best to choose the original special charger, otherwise it will affect or damage the polymer lithium battery.
2. When charging lithium batteries, it is best to use slow charging. Avoid fast charging as much as possible. Repeated charging and discharging will also affect the life of lithium batteries.
3. Avoid charging at excessively high temperatures. If you use a lithium battery in an environment that is higher than the specified operating temperature, that is, above 40 ° C, the battery's power will continue to decrease, that is, the battery's power supply time will not be as usual long.
4. Avoid charging at too low temperature. If you use the lithium battery in a low temperature environment, that is, below 0 ° C, you will also find that the battery life is reduced. Some mobile phones' original lithium batteries can not even be charged in a low temperature environment.
5. Before the lithium-ion battery leaves the factory, the manufacturers have activated it and pre-charged it, so the lithium-ion battery has residual power. The lithium-ion battery is charged according to the adjustment period. This adjustment period requires 3 to 5 full charges and discharges.
Charging characteristics of parallel lithium battery packs:
The purpose of paralleling lithium batteries is to increase capacity. Therefore, compared with single-cell lithium batteries, parallel charging of lithium batteries has different design characteristics, which are mainly reflected in the consistency of the charging current design and parallel batteries.
The characteristics of parallel lithium batteries are: constant voltage, battery capacity added, internal resistance reduced, and power supply time extended. The core content of parallel charging is the magnitude of the parallel current and its role. According to the parallel theory, the main current is equal to the sum of the currents of the branches. Therefore, n parallel lithium batteries that have been combined into a battery pack must achieve the same charging efficiency as a single battery.
However, the internal resistance of the battery after the parallel connection will also change. According to the parallel internal resistance formula, the total internal resistance of the two parallel lithium batteries is equal to the ratio of the internal resistance product of the two batteries and the sum of the internal resistances. The number of parallel batteries increases and decreases. Therefore, the efficiency of parallel charging of lithium batteries can be achieved on the basis that the current is less than the sum of the currents of n parallel lithium batteries.
When charging lithium batteries in parallel, pay attention to the consistency of the cells, because the parallel lithium batteries with poor consistency will not be charged or overcharged during the charging process, which will damage the battery structure and affect the battery life. Therefore, when using parallel batteries, lithium batteries of different brands, different capacities, and different levels of old and new should be avoided. The inherent requirements for battery consistency are: lithium battery cell voltage difference ≤10mV, internal resistance difference ≤5mΩ, capacity difference ≤20mA.