BLOGS
2019-01-30
LG once reported that more than 90 percent of people would feel anxious if their phone ran out of power, 41 percent would miss an important call when their phone was low and 17 percent of men would easily miss a date if their phone ran out of power -- a phenomenon known as "low battery anxiety."
As phones carry more and more important functions, power outages are becoming a problem. In order to reduce the "low battery anxiety" of modern people, it is necessary to improve the charging speed of mobile phones as much as possible, and the rapid charging technology emerges at the right moment.
In 1991, SONY and asahi chemical jointly released the first commercial lithium battery. Since then, lithium battery has been widely used in 3C products, including mobile phones. Aifaner (WeChat ID: ifanr) has mentioned the working principle of lithium battery in previous articles:
Lithium battery is divided into positive electrode and negative electrode, the positive electrode is lithium compound, the negative electrode is mainly made of graphite material, are immersed in the electrolyte.
Whether discharging or charging, it is actually the movement of lithium ions between the positive and negative poles of the battery, as well as the conversion of electrical energy and chemical energy. During charging, due to the action of the electric field, lithium ions move from the positive pole to the negative pole and store energy. When discharging, the lithium ion moves from the negative pole to the positive pole under the action of the chemical reaction. At this time, the current supply is formed.
The rate at which a lithium battery is charged is actually the rate at which electrical energy is converted to chemical energy, which is called electric power.
The more current or voltage there is, the more power there is, and lithium batteries are supposed to charge faster. However, due to the limitation of lithium battery itself, under or over voltage charging will cause damage to the battery. Therefore, the charging mode of lithium battery is special, which is usually divided into three stages:
When the phone is completely out of power, the charger first charges the lithium battery through a constant current with a small current to slowly restore its activity. After a period of time, the charger will increase the constant current and gradually increase the voltage, which is the main stage of lithium battery charging; When the battery is about 80% full, the charger will slowly reduce the input current at a constant voltage until the current falls below a certain critical value, at which time the phone will be fully charged.
Such charging process is generally controlled by the built-in power management chip of the phone, while the charger is mostly just regulated according to the instructions of the power chip.
Therefore, if you want to improve the charging speed of mobile phone lithium battery, you must work hard in the "high current constant current charging" stage.
In the era of feature phones, mobile phones have low requirements for battery capacity and lithium battery technology is not mature. In order to make lithium battery charging more stable, most manufacturers followed the national recommended low-rate charging standard "5V 0.2c" -- that is, charging voltage is 5V and charging current is 0.2c.
However, with the arrival of the era of smart phones, the demand for electric power of mobile phones has increased greatly, and the low rate charging standard has been difficult to meet the demand for charging. At this time, lithium battery technology also has a greater development, better stability, charge and discharge tolerance has been improved, "quick charge" began to appear on the stage.
What is "quick charge"?
In essence, "quick charge" is a technology that increases the power of a mobile phone within a reasonable range, aiming to quickly replenish most of its battery. Since the power is related to the size of voltage and current, "quick charge" can be divided into the following two schemes: what is "quick charge"?
"Quick charge" is a complete set of charging solution, which requires the coordination of the built-in power management chip, charging line and charger.
The iPhone is a classic counterexample. Although the iPhone 8 and iPhone X already support quick charging, the supporting charging head is the specification of "5V 1A", and the power is only 5W at full load, so the charging efficiency is very low.
Qualcomm recognized the importance of fast charging for smartphones back in 2013 when it introduced the Quick Charge 1.0 standard, which improves charging efficiency by increasing input current, and enables phones powered by snapdragon 600 processors to support "5V 2A" charging.
But because of the micro USB interface's limitations, any current above 2A is likely to cause damage, so qualcomm came up with another solution -- increasing the interface's voltage. By limiting the input current to 2A, the power can also be increased by increasing the supply voltage.
Through continuous improvement, qualcomm's Quick Charge 2.0/3.0 can achieve "9V 2A", that is, charging at a maximum power of 18W.
The "high voltage and low current" quick Charge scheme has inspired many peers. Mediatek's Pump Express Plus 1.0/2.0, samsung's Fast Charge and meizu's mCharge 3.0 are similar solutions.
However, after the high voltage is input into the phone, there will be a step-down process, and at this time, there will be heat loss inside the phone, resulting in severe fever. As a result, many phones that use this system won't activate the quick charge when the screen lights up to prevent overheating.
In addition, due to the competitive relationship between manufacturers, although the principles of fast charging are similar, there are compatibility problems between them. Therefore, to improve the charging efficiency, the first thing is to choose a charger with good compatibility.
After figuring out the principle and type of quick charging of mobile phones, the ways to improve the charging speed of mobile phones will be clear at a glance:
The first two points are easy to understand and belong to the skills that can slightly improve the charging speed.
For mobile phones with "high voltage and small current" quick charging scheme, the quick charging is usually not activated when the screen is bright to prevent overheating of the body due to the voltage reduction process inside the mobile phone and the heat loss.
With "power-saving mode," as iOS calls it, "low-power mode," the system consumes less power and charges faster. At present, apps such as Fast Charging, which are touted as a way to charge faster, work on a similar principle -- Charging a phone faster by tightly controlling its power consumption.
It is worth mentioning that the charging power of the mobile phone is controlled by the mobile phone, and there is a "handshake protocol" between different standards. The charger will automatically adjust the input power according to the instructions of the phone, so there is no need to worry about the problem of high-power charger burning the phone. High-power chargers, on the other hand, don't tend to run at full load, so they generate less heat than low-power chargers.
Choose sopower's phone charging cabinet and store your phone safely in the cabinet. Quick charging is convenient and fast, and will not cause harm to your phone. Sopower is your expert in quick charging.
