It allows compatible devices, such as smartphones, to receive power when placed on a Qi charger, which can be effective over distances up to 4 cm (1.6 in).

[3] As of December 2023[update], there are 351 manufacturers working with the standard including Apple, Asus, Google, Huawei, LG Electronics, Samsung, Xiaomi, and Sony.

The magnetic field induces an alternating current in the receiving coil by Faraday's law of induction.

In the first concept – called guided positioning – a user must place the Mobile Device on a certain location of the Base Station's surface.

The second concept – referred to as free positioning – does not require the user to place the Mobile Device in direct alignment with the transmitting coil.

The diagram shows the transmitting coil (array) generating the magnetic field as part of the power conversion unit.

This series resonant circuit is then driven by an H-bridge switching arrangement from the DC source; at full power, the voltage in the capacitor can reach 50 volts.

These designs allow frequency-agile operation at frequencies from 105 to 205 kHz and with maximum resonant circuit voltages as high as 200 volts.

In backscatter modulation, the power-receiver coil is loaded, changing the current draw at the power transmitter.

[16] Other phone companies that use proprietary standards for fast wireless charging include Apple, Huawei and Google.

[citation needed] With Qi version 2.0, WPC introduced Magnetic Power Profile (MPP), an optional part of the specification based on Apple's MagSafe for iPhone.

[21] In 2012, The Coffee Bean and Tea Leaf, a major US coffee chain, announced plans to install inductive charging stations at selected major metropolitan cities,[22] as did Virgin Atlantic, for United Kingdom's London Heathrow Airport,[23] and New York City's John F. Kennedy International Airport.

[25] Furniture retailer IKEA introduced lamps and tables with integrated wireless chargers for sale in 2015,[26] and the Lexus NX gained an optional Qi charging pad in the center console.

[27] An estimated 120 million wirelessly charging phones were sold that year,[25] notably the Samsung Galaxy S6, which supported both Qi and the competing Power Matters Alliance standards.

[30] Apple also announced plans to expand the standard with a new protocol called AirPower which would have added the ability to charge multiple devices at once; however, this was canceled on March 29, 2019.

[34] On September 9, 2024, alongside the announcement of the iPhone 16 models and iPhone 16 Pro models, Apple launched the new fast 25W MagSafe charger to feature the woven braided cable design, available in 1m and 2m length options and maintaining the compatibility with the fast 15W Qi2-certified wireless charging.