The first step to mastering a smartphone is how to complete charging quickly. The charging speed varies depending on the battery / USB-AC adapter and USB cable used, but it is better to know whether it is "rapid charging" or not.
Some Android devices display a status such as "rapid charging" when charging. However, this language is not always accurate.
This is because there is an Android terminal that determines that the battery is charging quickly if it finds that the charging cable is connected. The dedicated charging cable used here is a DCP (Dedicated Charging Port) specification with two signal lines, “ D + '' and “ D- '', used for USB data transmission, short-circuited, and supports a maximum of 1.5A. You.
There are cases where it is correct (rapid current of 1A or more), but it is not always possible to charge quickly because it is a dedicated cable for charging. In fact, USB ports of home appliances such as TVs-many of which have a maximum of 5 V / 0.5 A that adheres to the USB 2.0 standard-are connected with a dedicated charging cable, but despite being displayed as fast charging It will be charged at less than 5V / 0.5A.
The actual speed of charging can be measured by inserting a USB current checker between the USB port and the USB cable, or by using an app that measures current. You may want to try it if you feel that charging is slow despite the message "Charging is fast."