Learning the Correct Charging Method for Lithium Batteries

The lifespan of lithium batteries is typically 300-500 charging cycles. Assuming that a full discharge provides a charge of 1Q, and ignoring the decrease in capacity after each charging cycle, a lithium battery can provide or be replenished with 300Q-500Q of power during its lifespan. This means that if you charge it every time after using 1/2 of the battery, it can be charged 600-1000 times; if you charge after using 1/3, it can be charged 900-1500 times. In general, if you charge randomly, the number of charges will vary. The key point is that, no matter how it is charged, the total amount of 300Q-500Q of power supplied is constant.

Thus, we can also understand it this way: the lifespan of a lithium battery is related to the total amount of power charged into the battery, not the number of charging cycles. Deep discharge and deep charge, or shallow discharge and shallow charge, have little impact on the lifespan of a lithium battery. Therefore, when certain MP3 manufacturers advertise that “this MP3 model uses a powerful lithium battery that can be charged over 1500 times,” they are simply deceiving consumers’ ignorance.

In fact, shallow discharge and shallow charge are more beneficial for lithium batteries. Only when the power module of the product calibrates the lithium battery is deep discharge and deep charge necessary. So, for products powered by lithium batteries, there is no need to be strict about the process. The priority should be convenience; charge it anytime without worrying about affecting the lifespan.

Avoid Charging in Excessive Temperatures
If you use a lithium battery in an environment with temperatures above the specified operating temperature, i.e., above 35°C, the battery’s capacity will decrease, and the device will not last as long as usual. Charging the device in such temperatures will further damage the battery. Even storing the battery in a hot environment will inevitably cause damage to its quality. Therefore, maintaining the battery within an optimal operating temperature range is a good way to extend the lifespan of lithium batteries.

Avoid Charging in Extremely Low Temperatures
Similarly, if a lithium battery is used in low temperatures, i.e., below 4°C, you will also notice a decrease in the battery’s usage time. Some original lithium batteries in mobile phones cannot even charge in low-temperature environments. However, there’s no need to worry too much—this is just a temporary condition. Unlike high-temperature usage, once the temperature rises, the molecules in the battery will warm up, and the battery will immediately return to its previous charge level.

Regular Usage
“Life is in motion.” To achieve the maximum efficiency of lithium-ion batteries, regular usage is essential to keep the electrons within the battery flowing. If you don’t use the lithium battery often, make sure to complete one full charging cycle every month to calibrate the battery, i.e., perform a deep discharge and deep charge once.