How does fast charging or quick charging work?

Batteries get charged when current is passed through them. Higher current and voltages lead to faster charge. But, a battery can take only so much. Excess current is dangerous and should be controlled by an IC (charge controller). This controller chip controls the overall electricity flow, in and out, of the battery. Generally, the amount of current that the controller draws is dictated by the phone's software.

Most of the devices can be charged using a USB. It follows a robust standard called the USB Power Delivery Specification. However, there are various companies that have fast charging standards who exceed the USB spec's to reduce the charging time — from hours to minutes. Following are some charging standards which are widely used.

Charging standards

	Voltage	Current	Max Power
USB 1.0	5V	0.5A	2.5W
USB 2.0	5V	0.5A	2.5W
USB 3.0	5V	0.5A/0.9A	4.5W
USB BC 1.2	5V	Up to 1.5A	7.5W
Quick Charge 3.0	5V/9V/12V	1.5A/3A	18W
USB 3.1 (USB-C + USB-PD)	5-20V	0.5A/0.9A/1.5A/3A/5A	100W

Apple fast charging

USB-PD, is implemented in Apple iPhone X, iPhone 8 and iPhone 8 Plus. This allows to charge your phone from 0 - 50 percentage in 30 minutes. The same standard is used by the 12-inch MacBook, iPad Pro, Google’s Chromebook Pixel, and Lenovo’s X1 Carbon. However, Apple doesn't provide the USB-PD compatible charger and cables in the box. By default Apple uses USB BC 1.2 standard for most of its iPhones.

Qualcomm Quick Charge

QC is one of the most widely used charging standard in the market. This technology is designed to deliver fast charging in phones featuring Qualcomm's Snapdragon system-on-chips. This feature can be leveraged by using a Qualcomm certified QC charger. Mivi offers chargers which are Qualcomm QC 2.0 and Qaulcomm QC 3.0 certified. These allow you to do more while spending less time for charging.

Mivi's range of fast charging devices include:

5.4A Dual port Quick Charge wall charger