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Qi Wireless Charging

Forrest Stroud
Last Updated May 24, 2021 7:53 am

Qi is a wireless charging technology used to wirelessly power electronic devices such as smartphones, tablets and wearable computing products. Qi, which is pronounced like “chee” and is taken from the Chinese word for “natural energy,” was created by the Wireless Power Consortium in 2009.

The consortium itself formed in 2008 as electronics and mobile device manufacturers like Sony, Samsung, LG, Motorola and HTC partnered to create a standard that would utilize electromagnetic induction principles to power devices without the need for wires.

Qi’s Competition in the Wireless Charging Market

The Wireless Power Consortium’s resulting Qi standard has emerged as the frontrunner in the battle for wireless charging market share against competing technologies such as the Power Matters Alliance’s PowerMat and the Alliance for Wireless Power’s (A4WP) Rezence.

The Power Matters Alliance and the A4WP have since allied as of February 2014 in an agreement to share their specifications in an effort to better compete against the Qi standard.

How Qi Wireless Charging Works

The Qi wireless charging standard enables inductive electrical power transfer over a maximum distance of up to 1.6 inches. A Qi Receiver, which is a mobile device compatible with the Qi standard, is placed on a Qi Sender charging station, which transmits power to the receiving device.

Mobile smartphones and tablets in a Qi wireless system are charged via resonant inductive coupling, or loosely coupled charging, in which multiple devices can be charged at once without the need to place the device(s) in a specific spot and position. This is in contrast to tightly coupled charging, wherein a device needs to be precisely positioned on a wireless charging pad before it can be charged.