Can the mobile phone be charged all night?

We often link our mobile phone to the charger and go to bed then. Can the mobile phone be charged all night?

There are two concerns for this issue, one is safety, and the other is the service life of battery.

There are two theories about battery loss caused by mobile phone charging all night. One is that the "battery memory effect" reduces the total capacity, and the other is to increase the battery cycle, so as to reduce the service life.

Battery memory effect 'refers to the reduction of battery capacity caused by multiple charging, but this often occurs in traditional nickel cadmium batteries. Nowadays, lithium batteries are basically used in mobile phones and other electronic products, and memory effect is very rare.

In addition, most of the statements mentioned in some product manuals in the past that it is recommended to fully charge and then deplete the power for the first time, or charge for 12 hours and then deplete the power to activate the battery also come from the traditional nickel cadmium rechargeable battery.

For lithium batteries, there is usually a corresponding charging test link before leaving the factory. The manufacturer has activated the battery in this process, and we do not need to activate the battery through full charge and discharge.

Will charging your phone all night reduce battery life? A charge cycle refers to a cycle consisting of 100% of the accumulated discharged charge and 100% of the accumulated fully charged charge, rather than a cycle in which the battery is fully charged. Therefore, it has nothing to do with battery life.

In addition, after the smart phone is fully charged, the power management IC chip in the smart phone will automatically cut off the current. At this time, the mobile phone is actually in the self discharge state, and the power consumption of the mobile phone in the standby state is very small all night, which can not support a power cycle.

So, is it OK to charge on and use the mobile phone in same time?

Some people say that playing while charging is bad for the mobile phone. What if it's going to catch fire.

Most mobile phones and chargers have control IC components, which can control the voltage and current. The products will not burn under normal conditions.

As for battery loss, after the mobile phone is connected to the power cord, it actually supplies power to the mobile phone through the charger. If the use power of the mobile phone is less than the charging power, the power will gradually increase. There is no need to worry too much about this.

What really affects the battery life is high temperature heating.

Common lithium batteries are divided into positive and negative electrodes. The so-called process of discharge and charging is actually the movement of lithium ions between the positive and negative electrodes of the battery. During charging, lithium ions move from the positive electrode to the negative electrode to store energy, while during discharge, lithium ions move from the negative electrode to the positive electrode to form current power supply, and oxidation and reduction reactions will also occur during the whole charging process.

The chemical reaction is extremely sensitive to temperature. When charging the mobile phone, it will inevitably generate heat, especially fast charging. The voltage and current are relatively large, and the calorific value will increase greatly.

If the mobile phone is used to watch videos and play games during charging, the mobile phone will run at high frequency, and the chip will also emit a lot of heat. At this time, the temperature superposition will lead to various side chemical reactions and destroy the chemicals in the battery.

Insufficient chemicals required for charging and discharging will naturally reduce the total power, resulting in reduced battery life of the mobile phone.

In order to avoid safety problems, most mobile phone manufacturers and chip manufacturers will restrict charging, or reduce the operating frequency of the mobile phone at high temperature to reduce the calorific value until the temperature of the mobile phone gradually drops.

Or reduce the charging frequency or even turn off the charging. Apple mentioned in the introduction of MagSafe's external battery that fast charging will overheat the iPhone, so it will limit the charging to 80% through software, and will not continue charging until the temperature decreases.

How to charge to prolong battery life?

Speaking of this, you will probably wonder how to charge in order to protect the battery and prolong its life. Start from 0%, or try to keep it at about 100%? The answer is No

The battery life of lithium battery is related to the number of complete charge and discharge cycles. Generally, the number of cycles consumed by the battery to reach 80% of the peak power is used as the quantitative identification.

According to the research conducted by power magazine, temperature, charge discharge current intensity and charging state range will affect the battery life. It is also mentioned above that high temperature will destroy the chemicals inside the battery and lose the battery life. Charging at room temperature is conducive to prolonging the battery life.

However, the charging and discharging current can not be controlled by us as users. Generally, manufacturers will adjust the charging and discharging current and voltage through special power management chips to protect the mobile phone battery on the premise of ensuring safety and efficiency.

The range of state of charge (DoD) is also called the discharge depth. Different discharge depths will have different effects on the battery life. Most battery manufacturers recommend that the battery power be between 40% - 80%.

In this way, the battery life anxiety will not be aggravated because the power is too low, and the battery cycle times can be prolonged.

Translated by gmtlight lithium battery technology department.