"The more a lithium battery is discharged, the more wear and tear the battery will wear," said Tom Hartley, a professor of electrical engineering at Akron University who helps NASA research extending battery life. "The more you charge the battery. , the loss of the battery will be greater. The lithium battery should be in the middle state of power, so the battery life will be long.”
       First of all, too high and too low state of charge have an adverse effect on the life of lithium batteries, and the number of charge and discharge cycles is secondary. In fact, most of the rechargeable times marked on the electrical appliances or batteries sold are based on the benchmark test of 80% discharge. Experiments have shown that for some lithium batteries of notebook computers, the battery voltage is often increased by 0.1 volts beyond the standard voltage, that is, from 4.1 volts to 4.2 volts, then the battery life will be halved, and then increase by 0.1 volts, the life will be reduced to the original 3 The long-term low-power or no-power state will increase the resistance to electron movement inside the battery, resulting in a smaller battery capacity. NASA has set the drain on the batteries on its Hubble Space Telescope at 10 percent of capacity to ensure that the batteries can be recharged and discharged 100,000 times without having to be renewed.

Lithium battery discharge
Secondly, temperature also has a greater impact on the life of lithium batteries (mobile phones and other small electronic devices can be ignored in this regard). An environment below freezing point may cause the lithium battery to burn out the moment the electronic product is turned on, while an overheated environment will reduce the capacity of the battery. Therefore, if the laptop uses an external power supply for a long time without removing the battery, the battery will be exposed to the high heat discharged from the laptop for a long time.
From the above, we can summarize the following points to ensure the capacity and life of lithium batteries:
At present, most of the batteries of electronic products use lithium batteries. Since the introduction of lithium-ion batteries in 1990, they have developed rapidly because of their excellent performance and are widely used in society. As a result, lithium battery manufacturers have also received large-scale develop. There is no need to charge the lithium battery to 100% full power, let alone use up the power. When the situation allows, try to keep the battery's power near half full, and the smaller the range of charging and discharging, the better;
The factory design of the GM Chevy Volt is to force the battery to be maintained at 20% to 80%, and the built-in battery of Apple laptops may also use this method (including some other laptops and electronic products), so that the battery can be used. The number of charge-discharge cycles increases.
Do not use lithium batteries (especially notebook lithium batteries) for a long time when the device uses an external power supply. Even if your notebook is well cooled, long-term 100% power is equal to the murder of lithium batteries.
1. If you use an external power supply to power your laptop for a long time, or the battery power has exceeded 80%, immediately remove the battery of your laptop, and you don’t need to fully charge the battery for normal charging, just charge it to about 80%; adjust the power supply of the operating system option, adjust the battery level alarm to more than 20%, usually the battery level should not be lower than 20%, and it needs to be charged before it drops to 20%;
2. For small electronic devices such as mobile phones, you should disconnect the power cord (including the USB port of the charging function) immediately after charging, which will damage the battery; you need to charge it frequently and remember to charge it, but it is not necessary to fully charge the battery;
3. Whether it is a notebook or a mobile phone, be sure not to let the battery run out;
4. If you want to travel, please fully charge the battery, but please remember to charge the electrical appliance at any time when conditions permit. For the battery life, be sure not to wait until the battery is drained.