The use of lithium-ion batteries.
1. How to charge a new battery? When using a lithium battery, it should be noted that the battery will enter a sleep state after being left for a period of time. At this time, the capacity will be lower than the normal value, and the usage time will be shortened accordingly.
But lithium batteries are easy to activate, as long as they undergo 3-5 normal charge and discharge cycles to activate the battery and restore normal capacity. Due to the inherent characteristics of lithium batteries, they have almost no memory effect. Therefore, the new lithium battery in the user's mobile phone does not require any special methods or equipment during the activation process.
For the issue of "activation" of lithium batteries, many opinions suggest that the charging time must exceed 12 hours and be repeated three times in order to activate the battery. The statement that 'the first three charges should be charged for more than 12 hours' is clearly a continuation of nickel batteries such as nickel cadmium and nickel hydrogen. So this statement can be said to have been a misconception from the beginning. There is a significant difference in the charging and discharging characteristics between lithium batteries and nickel batteries, and it can be clearly stated that all the serious formal technical materials I have reviewed emphasize that overcharging and overdischarging can cause huge damage to lithium batteries, especially liquid lithium-ion batteries. Therefore, it is best to charge according to standard time and methods, especially not for over 12 hours of long charging (the charger shows full charge).
In addition, lithium batteries or chargers will automatically stop charging after the battery is fully charged, and there is no so-called "trickle" charging that lasts for more than 10 hours for nickel chargers. That is to say, if your lithium battery is fully charged and placed on a charger, it will still be charged for nothing. And none of us can guarantee that the characteristics of the battery's charge and discharge protection circuit will never change and the quality will be foolproof, so your battery will be hovering on the edge of danger for a long time. This is also another reason why we oppose long charging.
In addition, another aspect that cannot be ignored is that lithium batteries are also not suitable for over discharge, which is also detrimental to lithium batteries.
When should charging start during normal use
It is often said that because the number of charging and discharging cycles is limited, the battery of a mobile phone should be used up as much as possible before recharging. In fact, the lifespan of lithium batteries is not related to this. Here is an example of an experimental table on the charging and discharging cycles of lithium-ion batteries. The data on cycle life is listed as follows: cycle life (10% DOD):>1000 cycles (100% DOD):>200 cycles, where DOD is the abbreviation for depth of discharge. From the table, it can be seen that the number of rechargeable cycles is related to the depth of discharge, and the cycle life at 10% DOD is much longer than that at 100% DOD. Of course, if converted to the actual total charging capacity: 10% * 1000=100, 100% * 200=200, the latter's complete charging and discharging is still better. However, the statement made by the previous netizen needs to be corrected: under normal circumstances, you should charge the battery according to the principle of using up the remaining battery before charging. But if your battery cannot last the entire day on the second day, you should start charging in a timely manner. Of course, if you are willing to carry the charger to the office, that's another matter.
The principle of recharging after the remaining battery power is not to go to extremes. A widely circulated saying, like long charging, is "try to use up the battery as much as possible". This approach is actually only used on nickel batteries to avoid memory effects, unfortunately it has also been passed down in lithium batteries today. There was an example of someone who continued to use their phone without charging it even after receiving a warning of low battery level and continued to use it until it automatically shut down. As a result, the phone in this example did not respond during subsequent charging and startup, and had to be sent to customer service for repair. This is actually due to the low voltage caused by excessive discharge of the battery, resulting in the inability to have normal charging and startup conditions.
My personal suggestion is not to fully charge the lithium-ion battery of a mobile phone or use it until it runs out of battery. Charging the battery before it is fully charged will not cause damage to the battery. Charging should be done within 2-3 hours, and it is not necessary to fully charge it. But the lithium battery should be fully charged (normal charging time) and discharged 1-2 times every 3-4 months or so. Lithium batteries that are not used for a long time should be stored in a cool and dry place, preferably in a half charged state (70-80% of full charge, if your phone displays 4 bars when fully charged, then 3 bars are sufficient). Storing a fully charged battery is dangerous and can damage the battery, while storing a battery without power can damage it. Every 3-6 months, check if you need to replenish electricity. Lithium ion batteries can be divided into liquid lithium-ion batteries and polymer lithium-ion batteries according to the electrolyte. The electrolyte of polymer lithium-ion batteries is colloidal and does not flow, so there is no leakage problem and it is safer.
