Under normal circumstances, the charging head of 2A supports fast charging.
< br >
The output current of most 18W fast charger is 2A. Meizu's 18W mCharge fast charger is Mediatek's PumpExpress fast charger, which uses 9V charging voltage and 2A charging current. The 18W charging power in the Qualcomm QC4 and USB PD fast charge protocols also uses the 9V\/2A charging output, that is, the 2A charging current.
< br >
？
< br >
Extended information:
< br >
When the mobile phone is charging, the charging head determines the size of the voltage and current, which is equivalent to " Faucet " The same is true for fast charging.
< br >
For example, Huawei SCP super fast charge, supports the output of 4.5V\/5A, charging power up to 22.5W, in addition to the QC3.0 fast charge output of 9V\/2A maximum power 18W, Samsung supports the AFC fast charge output of 12V\/2.1A, 9V\/1.67A, the maximum power of 25W. Apple mobile phone support PD fast charge is also output 9V\/2A maximum power 18W.
< br >
Fast charging technology: VOOC flash charging
< br >
VOOC flash charge 5 minutes for 2 hours of talk, charging 30 minutes can charge the phone's battery from 0% to 75%.
< br >
On February 23, 2016, Barcelona, Spain, OPPO demonstrated its latest black technology at the 2016 Mobile World Congress, which mainly includes the latest achievements in fast charging and image technology - OPPO VOOC super flash charge and SmartSensor image chip anti-shake technology. OPPO VOOC Super Flash Charge fully charges a 2,500mah phone in 15 minutes.
< br >
Fast charging technology: Qualcomm Quick Charge 2.0
< br >
Qualcomm's Quick Charge 2.0 technology is an upgraded version of Quick Charge 1.0 with a new specification. The charging speed is improved by increasing the current and voltage at the same time.
< br >
Fast charging technology: Mediatek Pump Express Plus
< br >
Mediatek's new fast-charging technology, the Pump Express, is built into PMIC's power management integrated circuit. The charger is allowed to determine the initial voltage required for charging according to the current, and the PMIC sends a pulse current command through the USB Vbus to the charger, and the charger adjusts the output voltage according to the command, and the voltage gradually increases to up to 5V to achieve the maximum charging current.
A charger above 5 volts and 2 amps is considered fast
< br >
Fast Charge 2.0 is 5V 2A, Fast charge 3.0 is 5V 3A. Fast charging doesn't hurt the battery, but frequent fast charging does hurt the battery compared to slow charging. 1, accelerate the polarization of the battery cell In general, during the charging process of the lithium-ion battery, the Li migration speed of the internal diffusion of the electrode is very small compared with the electrolyte, and the internal diffusion of the electrode is the control step of the Li diffusion rate. When the continuous charging current is large, the ion concentration at the electrode increases, the polarization is intensified, and the battery terminal voltage cannot be directly proportional to the charge\/energy. 2, may lead to cell crystallization in the charging process, the control of lithium ions is actually very weak. We can only guarantee that lithium ions will migrate to the negative surface, but we cannot guarantee that lithium ions will be evenly distributed on the negative surface.
Generally speaking, most of the power of the ordinary charging head is less than or equal to 10w, that is, 5v2a. So now the common specifications are 18w, 30w, 65w and so on are called fast charge. Around 20w and above are considered fast charge.
< br >
The difference between various fast charging mobile phones: First, popularize two formulas: energy W (can be regarded as battery capacity) = power P× time T; power
< br >
P= voltage U x current I. In the case of a fixed battery capacity, fast charging is to shorten the charging required by increasing the charging power P
< br >
Between. There are three ways to increase the power, which are increasing the voltage, increasing the current and increasing the voltage and current at the same time. These three ideas are produced
< br >
Gave birth to three representative fast charge technology: Qualcomm Quick
< br >
电荷
< br >
3.0\/2.0, Mediatek Pump
< br >
快车
< br >
另外
< br >
As the representative of high voltage fast charge; OPPO
< br >
VOOC flash charge, USB
< br >
3.1
< br >
Low voltage fast charge represented by PD. (Other phone manufacturers are fast
< br >
Most of the schemes come from these three, or are developed on the basis of these three).
According to the definition given by the \"Theil Forum 2017 Fast Charging Technology Standards and Application Seminar\
After the test of the power adapter manufacturer, the iPhone12 uses the original 20W charger to charge, charging about 60% in half an hour, charging 88% in 1 hour, and fully charging takes about 1 hour and 40 minutes. Meet the fast charging conditions, so it is not fast charging, is determined by the input current and the charging speed of the first half hour, and the charging power has little to do with it.
Generally speaking, most of the power of the ordinary charging head is less than or equal to 10w, that is, 5v2a. So now the common specifications are 18w, 30w, 65w and so on are called fast charge. Around 20w and above are considered fast charge.