How to use lithium ion batteries correctly

1. How to charge a new battery

In the use of lithium batteries, it should be noted that after the battery is left for a period of time, it will enter the dormant state. At this time, the capacity is lower than the normal value, and the use time is also shortened. But the lithium battery is easy to activate, as long as 3-5 normal charge and discharge cycles can activate the battery and restore normal capacity. Due to the characteristics of the lithium battery itself, it is determined that it has almost no memory effect. Therefore, the new lithium battery in the user’s mobile phone does not require special methods and equipment during the activation process. Not only is this true in theory, but from my own practice, it is best to use the standard method of charging from the beginning, which is the “natural activation” method.

Regarding the issue of “activation” of lithium batteries, many claims are: the charging time must be more than 12 hours, repeated three times in order to activate the battery. This statement of “charging for more than 12 hours in the first three charges” is obviously a continuation of the statement from nickel batteries (such as nickel-cadmium and nickel-metal hydride). So this statement can be said to be misinformation at the beginning. The charging and discharging characteristics of lithium batteries and nickel batteries are very different, and I can tell you very clearly that all the serious official technical materials I have consulted emphasize that overcharge and overdischarge will affect lithium batteries, especially liquid lithium. Ion batteries cause great damage. Therefore, it is best to charge according to the standard time and standard method, especially not to charge more than 12 hours. Generally, the charging method described in the manual of the mobile phone is the standard charging method suitable for the mobile phone.

In addition, lithium battery mobile phones 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 in nickel battery chargers. In other words, if your lithium battery is fully charged, it is also white charged on the charger. And none of us can guarantee that the characteristics of the battery’s charging and discharging protection circuit will never change and the quality will be foolproof, so your battery will be on the verge of danger for a long time. This is another reason why we oppose long charging.
In addition, on some mobile phones, after charging for a certain period of time, if the charger is not removed, the system will not stop charging at this time, but will also start a discharge-charge cycle. Perhaps the manufacturer of this approach has its own purpose, but it is clearly detrimental to the life of the battery and mobile phone/charger. At the same time, long-term charging takes a long time and often needs to be carried out at night. According to the situation of my country’s power grid, the voltage at night in many places is relatively high and fluctuates greatly. As mentioned earlier, lithium batteries are very delicate, and their ability to withstand fluctuations in charging and discharging is much worse than that of nickel batteries, so this brings additional dangers.

In addition, another aspect that cannot be ignored is that lithium batteries are also not suitable for overdischarge, and overdischarge is also very detrimental to lithium batteries. This leads to the following question.


2. When should the charging start in normal use

We can often see this statement, because the number of charging and discharging is limited, so the mobile phone battery should be used up as much as possible to recharge. But I found an experimental table on the charge and discharge cycle of lithium-ion batteries. The data on the cycle life is listed as follows:

Cycle life (10%DOD): >1000 times
Cycle life (100%DOD): >200 times

Among them, DOD is the abbreviation of Depth of Discharge. It can be seen from the table that the number of rechargeable times 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 it is converted to the relative total capacity of actual charging: 10%*1000=100, 100%*200=200, the latter’s full charge and discharge is still better, but the previous netizen’s statement needs to be corrected: in normal In this case, you should reserve the battery according to the principle of recharging when the remaining battery power is used up, but if your battery is not likely to last the entire day on the second day, you should start charging in time. Of course, if you are willing to carry it back It’s another matter of bringing the charger to the office.

And you need to charge to cope with the upcoming important events that are expected to cause busy communication, even when the battery has a lot of remaining power, then you only need to charge in advance, because you have not really lost the “1″ charge cycle life. , Which is just “0.x” times, and often this x will be very small.

The principle of recharging the remaining battery power is not to make you go to extremes. Like long-term charging, a widely circulated saying is “try to use up the battery of the mobile phone as much as possible, and it is best to use automatic shutdown.” This approach is actually only the approach on nickel batteries, the purpose is to avoid the memory effect, unfortunately, it is also spread today on lithium batteries. There was an example where someone continued to use the phone without charging after a warning that the battery level of the mobile phone was too low, until it was automatically shut down. As a result, the mobile phone in this example did not respond during subsequent charging and booting, and had to be sent to customer service for overhaul. This is actually because the battery voltage is too low due to over-discharge, so that it does not
It is caused by having normal charging and starting conditions.


3. The correct approach to lithium-ion batteries

In summary, my most important tips for the charging and discharging of lithium battery mobile phones in use are:

①Charge according to the standard time and procedure, even if it is the first three times;
②When the phone battery is too low prompt, you should try to start charging as soon as possible;
③The activation of the lithium battery does not require a special method. The lithium battery will be naturally activated during the normal use of the mobile phone. If you insist on using the popular “first three 12-hour long charge activation” method, it won’t actually work.

Therefore, all pursuits of 12-hour long charging and automatic shutdown of mobile phones with lithium batteries are wrong. If you did something wrong in the past, please correct it in time, maybe it’s not too late.

Post time: Apr-06-2021