One big obstacle to wireless charging is that it takes significantly longer than traditional wired charging. Now, the Wireless Power Consortium has released the latest version of its Qi wireless charging specification to close the gap.
The new specification is capable of transmitting 15 watts wirelessly, three times the amount of power as current Qi-based products. For now, there aren't any phones that can support 15W wireless charging, but the new standard is backwards-compatible with existing Qi hardware.
The new specification is initially available only to WPC members, but will be released in a public document in the future. It could take as long as two years for manufacturers to design and test 15W wireless charging chips, said John Perzow, WPC's president, in a statement.
This specification provides the same amount of power as several of the fastest wired charging solutions. Qualcomm’s Quick Charge technology, for instance, generates 15W of wired power and is capable of providing over a 50% charge in about 30 minutes to a 3300mAh battery.
The Qi wireless charging standard uses both inductive coupling and magnetic resonance technology to transmit power to devices. The Qi system generally features a charging pad, connected to a power source and containing a transmitter, and a power receiver embedded in the device. The transmitter generates an oscillating magnetic field, which induces an alternating current in the receiver coil, producing a charge in the battery. For the Qi standard, the distance between the two coils is typically 5mm.
The WPC has also approved the tests and tools to verify that fast-charging products comply with the specification. The organization, which has almost 200 members, has also released medium- and high-power specifications for charging personal computers and cars, respectively.
The Wireless Power Consortium is one of three main standard bearers for wireless charging. The two others — the Alliance for Wireless Power (A4WP) and Power Matters Alliance (PMA) — agreed to merge in July and plan to release a combined wireless charging standard.