Excessive or insufficient charge levels have the most detrimental impact on the lifespan of lithium-ion batteries, while the number of charge-discharge cycles is secondary. In fact, the number of rechargeable cycles indicated on most commercially available appliances or batteries is based on testing at 80% discharge. Experiments show that for some laptop lithium-ion batteries, frequently exceeding the standard voltage by 0.1 volts (from 4.1 volts to 4.2 volts) halves the battery's lifespan; increasing it by another 0.1 volt reduces it to one-third of its original lifespan. Prolonged low or no charge levels increase the resistance to electron movement within the battery, leading to reduced battery capacity. NASA sets the battery consumption on its Hubble Space Telescope at 10% of its total capacity to ensure it can be recharged and discharged 100,000 times without needing replacement.
Secondly, temperature also has a significant impact on the lifespan of lithium-ion batteries (this effect is negligible for mobile phones and other small electronic devices). Sub-zero temperatures can cause lithium-ion batteries to burn out the moment the electronic device is turned on, while overheating will reduce battery capacity. Therefore, if a laptop is used with external power for extended periods without removing the battery, the battery will be constantly exposed to the high heat emitted by the laptop. More importantly, keeping the battery at 100% charge for extended periods will quickly render it unusable.
Do not leave lithium-ion batteries (especially laptop lithium-ion batteries) running for extended periods while the device is connected to external power. Even if your laptop has good cooling, keeping it at 100% charge for a long time is tantamount to killing the lithium-ion battery.
1. If you are using an external power source to power your laptop for extended periods, or if the battery level is above 80%, immediately remove the laptop battery. When charging, do not fully charge the battery; charge it to around 80%. Adjust the operating system's power options to set the battery warning level above 20%. Never let the battery level drop below 20%, and charge it before it reaches 20%.
2. For small electronic devices such as mobile phones, the power cord (including USB charging ports) should be disconnected immediately after charging. Leaving it plugged in will damage the battery. Charge it frequently, whenever you remember, but it is not necessary to fully charge the battery.
3. Whether it's a laptop or a mobile phone, never let the battery run completely drained;
4. If you are going on a trip, make sure to fully charge the battery. But remember to charge your devices whenever possible. To extend battery life, never let the battery run completely dry.
