In the low-temperature environment, the chemical reaction rate becomes slower, the resistance value of the electrolyte becomes larger, the lithium-ion traversing performance becomes worse, the activity decreases, and the discharge current becomes smaller, resulting in a decrease in the usable capacity of the battery. Lithium batteries consume a lot of power at low temperatures, which is actually the illusion of everyone. The essence is that the battery capacity of the lithium battery itself is reduced.
Electrical conductivity and material activity in the cell
Experimental data: The power consumption of the same mobile phone at -5 °C is 1.7 times that of 20 °C. The essence is that the current of the lithium battery becomes smaller and the available capacity is reduced.
When the mobile phone detects that the battery capacity is low, and the ambient temperature is low, resulting in a small current, the temperature protection circuit in the battery built-in protection board is activated, and the mobile phone will automatically shut down. When the ambient temperature returns to the normal value and the temperature protection circuit are turned off, the mobile phone can work normally.
In order to avoid the above situation, in the low-temperature environment, it is best not to use the mobile phone for a long time. When you go out, you should put the mobile phone in your pocket, pack and other places where you can keep warm. You can also buy a thick mobile phone case for your mobile phone to keep warm.
In fact, condensed water is more serious than low temperature. Returning from the cold outside to the indoors, the warm air in the room condenses in the cold, and water vapor is generated on the mobile phone. If water vapor enters the motherboard, the phone will get wet, crash or fail to boot. Therefore, in the case of a large temperature difference, avoid the phone is exposed, if you have to talk, you can plug in the headset.
In fact, many factors will affect the mobile phone battery, but the temperature has the greatest impact on the battery. The impact of low temperature on the mobile phone battery is mainly manifested in three aspects. First, as mentioned above, it will affect the conductivity and material activity in the battery. To reduce the battery capacity, secondly, the low temperature easily causes the circuit board to form a mist and cause a short circuit. In addition, the battery is affected by the low-temperature environment for a long time.
If it is only studied from the viewpoint of capacity, the electrolyte used for the lithium battery acts as an organic liquid, like grease, and becomes viscous or even condensed at a low temperature. At this time, the activity of the conductive lithium salt is greatly limited in the inside, so that the charging efficiency is very low, which may cause the lithium battery to be charged slowly at a low temperature, and the charging is not full, and the discharge is also the same.
The perspective of battery capacity
Although the normal operating temperature of the mobile phone battery is relatively wide, as the temperature is lowered, the discharge performance of the lithium battery will be significantly reduced, the discharge platform will be significantly reduced, and the discharge capacity will be significantly reduced. However, because of the different battery performance of different brands, there is a certain difference in low-temperature resistance. Therefore, some users say that the capacity change of a battery with a capacity of 3000 mA at 30 degrees in a low-temperature environment is unpredictable but generally Say, as long as the temperature is above zero degrees Celsius, the available capacity of the mobile phone battery will not drop significantly.
In addition, it seems that there is no official data on the influence of temperature on battery capacity on the Internet. Only the capacity performance of a certain brand battery affected by temperature can be found. You can refer to When the temperature drops to -30 °C, the discharge capacity of the battery is the room temperature discharge capacity. 87.0%, the average discharge voltage is reduced by 0.598V compared with room temperature, and the stored energy is only about 70% of the ordinary environment. The constant current charging capacity of the lithium-ion battery is only 14% of the total charging capacity, and the constant voltage charging time is It will also become very long.
It can be seen that the effect of extremely low temperature on the battery is very large, but it is not as exaggerated as we think. It is estimated that the temperature should be below 10 degrees and the battery capacity should be more than 90% efficient. If you can avoid exposing your phone to a low temperature when you are at a low ambient temperature, try to keep your phone’s operating temperature above zero degrees Celsius. After using it for a while, the mobile phone’s own heat will gradually work.
Custom low-temperature battery
Grepow low temperature battery can effectively improve the discharge performance of the battery in the low-temperature environment, reduce the internal resistance of the battery, and achieve the effect of high rate discharge. Therefore, its battery life is longer and its power is stronger. This is also one of the core technologies of Grepow, which has the following advantages:
Wide operating temperature range, -40 ° C to 50 ° C. Compared with traditional Li-Polymer batteries, it has broken through the discharge temperature limits of -20℃ to 60℃.
High performance of discharge at low-temperature, the lowest one is able to discharge over 60% efficiency @0.2C at -40℃, and discharge over 80% efficiency @0.2C at -30℃.
Flexible size, the battery can be designed according to customer’s size. For example, irregularly shaped batteries:
Can be widely used in cold climates and military products. With the ability to mass production, cell consistency is good.