Charging knowledge

Charging voltage
Generally, the battery voltage of the mobile phone is written as 3.7V, but the voltage of the general charger is written as 5V, but it will not affect the use, because there is a charging management chip inside the mobile phone that is responsible for step-down and constant current charging.
No. 5 cylindrical lithium battery, i.e. 14500 battery. It is a lithium battery voltage regulator technology that adjusts the voltage of the battery to a voltage of 3.0V suitable for small electrical appliances.
As for the "activation" of the newly bought lithium-ion battery, many statements are: the charging time must exceed 12 hours, and it must be repeated three times in order to activate the battery. This statement that "the first three charges should be charged for more than 12 hours" is obviously a continuation of nickel batteries (such as nickel-cadmium and nickel-metal hydride). So this statement can be said to be misinformation from the beginning. There is a very big difference between the charging and discharging characteristics of lithium batteries and nickel batteries, and it can be very clear that all serious formal technical information emphasizes that overcharging and overdischarging will cause great harm to lithium batteries, especially liquid lithium-ion batteries. Therefore, it is best to charge according to the standard time and standard method, especially not to charge for more than 12 hours.
The battery also needs to be activated. But this process is done by the manufacturer, and it has nothing to do with the user, and the user is not able to complete it. The real activation process of lithium battery is as follows: the lithium-ion battery shell is filled with electrolyte-sealing-formation, that is, the constant voltage charge, and then discharged, so that several cycles are carried out to fully infiltrate the electrode and fully activate the electrolyte until the capacity reaches the requirements, which is the activation process - volume, that is to say, the lithium-ion battery has been activated to the user's hand after leaving the factory. In addition, the activation process of some batteries requires the battery to be in an open state, and then sealed after activation.
The manuals of some products say that it is recommended that users use the phone completely for the first three times. In fact, the fact is that the battery will go through a period of time, a month or a few months, when the battery leaves the factory, then sold, and then into the hands of the user, so that the electrode material of the battery will be "passivated", and the capacity will be lower than the normal value, and the use time will be shortened. However, the lithium battery is easy to activate, as long as it goes through 3-5 normal charging and discharging cycles, the battery can be activated and the normal capacity can be restored. Due to the characteristics of the lithium battery itself, it is determined that it has almost no memory effect. Therefore, the user's new lithium battery does not need special methods and equipment during the activation process.
Long charge and deep charge
Prolonged charging may result in overcharging. Lithium batteries or chargers will automatically stop charging when the battery is fully charged, and there is no so-called "trickle" charging that lasts for more than 10 hours as nickel electric chargers. That is to say, if the lithium battery is fully charged, it is also white charged when placed on the charger. No one can guarantee that the characteristics of the battery's charge-discharge protection circuit will never change and the quality will be foolproof, so the battery will be on the verge of danger for a long time. This is another reason against long charging.
On some machines, if the charger is not removed after charging for more than a certain period of time, the system will not only not stop charging, but will also start a discharge-charge cycle. Perhaps the manufacturers of this approach have their own purposes, but apparently it is for the life of the battery