The Factors Affecting Battery Life

- May 28, 2020-

Factor 1: Depth of discharge and rechargeable times

According to the test, the number of rechargeable times is related to the depth of discharge. The deeper the battery discharges, the fewer the number of rechargeable times.

Rechargeable times * depth of discharge = total number of charge cycle completions, the higher the total number of charge cycle completions, the higher the battery life,so actual battery life = rechargeable times * depth of discharge  (ignoring other factors)

Factors 2: Overcharge&Overdischarge, and large charging and discharging current

Avoid overcharging the battery. Any form of overcharging of the lithium ion battery will cause serious damage to the battery performance or even explosion.

Avoid deep discharge below 2V or 2.5V, as this will quickly and permanently damage the lithium ion battery. Internal metal plating may occur, which can cause a short circuit, making the battery unusable or unsafe. Most lithium-ion batteries have an electronic circuit inside the battery pack. If the battery voltage is lower than 2.5V, exceeds 4.3V when charging or discharging, or if the battery current exceeds a predetermined threshold, the electronic circuit will disconnect. Avoid large charging and discharging currents, because large currents put excessive pressure on the battery.

Factor 3: Overheated or cold environment

Temperature also has a greater impact on the life of lithium batteries. The environment below freezing point may cause the lithium battery to burn out when the electronic product is turned on, while the overheated environment will reduce the capacity of the battery. Therefore, if the notebook does not remove the battery after using the external power supply for a long time, the battery will be in the high heat of the notebook for a long time, and it will soon be scrapped.

Factor 4: Full power or no power state for a long time

Too high and too low power states have an adverse effect on the life of lithium batteries. Most of the rechargeable times marked on the sold electrical appliances or batteries are based on the 80% discharge test. Experiments have shown that for lithium batteries of some notebook computers, the battery voltage often exceeds the standard voltage by 0.1V, that is, from 4.1V to 4.2V, then the battery life will be halved, and if it is increased by 0.1V, the life will be reduced to 1 / 3; The more fully charged the battery, the greater the loss of the battery. The long-term low or no power state will make the internal resistance of the battery to the movement of electrons greater and greater, which will cause the battery capacity to become smaller. Lithium batteries are best in the middle of power, in which case the battery life is the longest.

From the above, the following points can be summarized to extend the capacity and life of the lithium battery:

1. If the external power supply is used to power the notebook computer for a long time, or the battery power has exceeded 80%, remove the battery immediately. Usually charging does not need to fully charge the battery, it can be charged to about 80%. Adjust the power options of the operating system, adjust the power alarm to more than 20%, and usually the battery power should not be less than 20%.

2. When charging a small electronic device such as a mobile phone, immediately disconnect the power cord when it finished the charge(including the USB port of the charging function), and continuous connection will damage the battery. Charge it often, but you don't have to fully charge.

3. Be sure not to drain the battery (automatically shut down) whether it is for a laptop or mobile phone.

4. If you want to travel, you can fully charge the battery, but charge the appliance at any time if conditions permit.

5. Use a smarter and power-saving operating system.