How much battery power is left on mobile phones is a "life-threatening" issue for many people in modern society. People's strong demand for mobile phone charging has also spawned many gimmicks on the market: wireless charging, double-speed charging, and high-energy power banks that can be used continuously for a week.The flowers are becoming more and more charming, but what is the correct posture for charging mobile phones?

Does the phone have to be fully charged?

Regarding charging, there are always some rumors circulating: recharge your mobile phone after it is exhausted. It should be fully charged every time. This is conducive to battery maintenance. Charging at any time will affect the battery life.In fact, these theories are relatively outdated.

Rechargeable batteries that were widely used in the early years, such as nickel-cadmium batteries, are mainly made of nickel hydroxide and metallic cadmium. Their shortcomings are obvious: they have a memory effect.

To put it simply, when the power is not exhausted or fully charged many times, the battery capacity will "remember" the power during charging and power outage, treating them as the maximum and minimum values ​​of power respectively, resulting in a reduction in battery capacity.

But now, nickel-cadmium batteries and other batteries have been gradually phased out due to heavy metal pollution, high weight, and low energy density, and have been replaced by lithium-ion batteries. Smartphones mostly use lithium-ion batteries. Compared with nickel-cadmium batteries, its advantages include: high energy density. Simply put, it means that the same volume or weight can store more power; the memory effect is weak, and it will not have any impact even if it is unplugged before it is fully charged.

The precautions for lithium-ion batteries are exactly the opposite of those for cadmium-nickel batteries: do not charge when they are empty, do not overcharge, and do not need to deeply charge and discharge each time.The life of a lithium-ion battery is related to the charging cycle. Whenever 100% of the power is used, a cycle is achieved. The more cycles, the more obvious the battery life decreases.

A study of 11 types of lithium ions showed that after 250 cycles, the battery capacity will decline significantly. After 300 to 500 cycles, the battery capacity will drop to 80% of its original capacity. What is the principle? Some data show that when lithium-ion batteries are deeply charged and discharged, the material structure of the positive and negative electrodes will be destroyed.

Lithium-ion batteries mainly rely on the movement of lithium ions between the positive and negative electrodes to work. Once the space for their activities becomes less, the battery capacity will decrease accordingly.

Therefore, compared to "charging full and full", "charging multiple times and less" is more suitable for the charging habits of current mobile phones. In addition to the power before and after charging, another issue that is easily overlooked by people also affects the service life of the battery.

Plug in the phone first or the charger first?

Should I connect the plug to the power supply first and then connect the data cable to the mobile phone, or should I connect the data cable to the mobile phone first and then connect the plug to the power supply? The answer is: the former. They are all charging. What impact will such subtle differences have? Here is a knowledge point: The voltage of electricity used by Chinese residents is 220V, but the voltage of mobile phone chargers is often within 5V. When charging mobile phones, the charger converts high-voltage current into low-voltage DC through a transformer, and then delivers it to the mobile phone.

At this time, if the charger is connected to the mobile phone and then plugged into the power supply, it can be regarded as directly connecting the mobile phone to the power supply, and a surge voltage may be output; on the other hand, if the plug is inserted first, it is already connected and the output has stabilized at around 5V, so surge voltage is unlikely to occur.

Surge, also known as surge, refers to an instant overvoltage that exceeds the normal operating voltage. Most of those shiny sparks you see sometimes when plugging and unplugging switches are surges. Although the time is only one millionth of a second, it can cause considerable damage to the battery of the mobile phone in the long run.But if you plug in the charger first and then connect the phone, this situation will almost never happen. Unless the current itself is unstable.

After charging, should I unplug the phone or the plug first? The answer is: unplug your phone first. Because the moment the charger is unplugged, a reverse instantaneous current will also be generated, which will accelerate the aging of the battery. The principle seems complicated, but it is not difficult to remember the correct order of plugging and unplugging. You can try to treat the charger, charging cable and socket as one. When charging, the phone is "attached", and when it is full, the phone is "abandoned". This operation is much safer.

Power banks are also affected by the "charging cycle"

Many people carry power banks with them in case they can’t find an outlet when they go out. It is indeed very convenient. A small mobile power supply can maintain the normal operation of the mobile phone, which is a lifesaver. But there are also many gimmicks and misunderstandings about power banks.

Currently, there are many power banks on the market that claim to be 20,000 mAh. But most mobile phones, even flagship versions, have battery capacities below 5,000 mAh. The "nail house" products in the early years only had a pitiful 2000 to 3000 mAh. After buying a 20,000 mAh power bank, wouldn’t it mean that a family of three would not have to worry about traveling for two days?

When you actually buy it, you will know that it will run out of power after being charged twice. Could it be that the merchant is making false propaganda? In fact, they played a word game.

The capacity marked by the merchant is mostly the capacity of the battery cell itself, which is the sum of the power of multiple lithium-ion batteries in the battery.Since the power will be lost during the conversion process, the effective power that the power bank can provide to the mobile phone is definitely lower than this data.

If you want to know how many times a power bank can really be used, you have to read the small print in the manual carefully: rated capacity. This is the minimum dischargeable capacity tested in the laboratory.

A media outlet once conducted a review and found that among those power banks that claim to have 20,000 mAh capacity, the actual capacity difference between the largest and smallest ones can be as much as 4,000 mAh, which is enough to fully charge most mobile phones. It should be noted that since the power bank also uses lithium-ion batteries, its lifespan is also affected by the charging cycle. It is also recommended to "charge less often" rather than "discharge fully".

How to charge correctly?

If the use of mobile phones also has a shortcoming effect, the battery is probably the shortcoming. However, in daily use, there are also some charging methods that you think are correct, but in fact they are not.

1Can’t you mix charging cables and chargers?

It is common practice to buy a mobile phone with supporting charging equipment. However, in recent years, some manufacturers no longer give away chargers in the name of environmental protection, and they can only buy them themselves. The price on the official website is too high, so many people will choose cheaper ones, thinking that the charging equipment itself is a consumable product. If the cat at home is not keeping an eye on it, the charging cable will be chewed to the point of being unusable. This also leads to the fact that after many people have used it for a long time, the charging cable, charger and mobile phone may not be matched.

As a result, many rumors came out: unmatched chargers will cause battery short circuits and affect service life.

In fact, this statement obviously underestimates the charger. There is usually a smart chip inside the charger, which can identify the current and voltage required by the mobile phone and adjust it. For example, if you buy a fast charging head, but the mobile phone does not support fast charging, then the fast charging head will automatically adjust to the input power of the mobile phone.

Some people complain that the fast charging head does not work, but this is actually the principle. However, when purchasing, you should also try to look for the legitimate brand, and don't buy a cheap copycat. After all, the configuration of the copycat charger is hard to say, and it is possible that the current and voltage required by the phone cannot be recognized, causing damage to the phone.

2 Don’t charge while playing?

Some people may think that discharging and charging the battery at the same time will affect the lifespan. In fact, what really affects the battery life is the sudden rise in temperature caused by charging while playing. Everyone will have this experience. When playing high-end games or using fast charging, the phone will get hot.

A survey shows that even if the mobile phone is not used, rising temperature will still accelerate the reduction of battery capacity. Therefore, for the sake of battery safety, it is best not to let it "multi-task".

In addition, you need to be careful not to buy a protective case that is too thick for your phone. There are many fancy protective cases on the market. They are good-looking, but not all of them are suitable for mobile phones.

Like computers and other devices, mobile phones also need to dissipate heat. If you wrap it tightly and use insulation materials, it will only make the phone look like there are no scratches on the outside, but there will already be damage on the inside.

To avoid high temperatures, be careful not to place your phone next to your pillow or in the sun before going to bed. This move not only protects your phone, but also you.