Wireless charging is set to hit the mobile device mainstream this year as big manufacturers and high street retailers step into the frame.
This is the takeaway from the analysts at IHS Technology, who predict shipment of devices capable of being charged wirelessly will more than double to 120 million this year, before reaching 2 billion units by 2024. “2015 looks to be a breakthrough year for wireless power technology,” said David Green, research manager for power supplies and wireless power for IHS.
Activity is heating up. Samsung, Apple, HTC, Nokia are all shipping or about to ship solutions integrating wireless charging, most notably the Apple Watch and Samsung Galaxy S6. On the high street IKEA has launched a range of domestic furniture with built in wireless charging features based on the Qi standard, carmakers are embedding wireless charging in their vehicles and big brands like Starbucks and McDonalds are offering or intend offering wireless charging areas in their high street stores.
What next? In future wireless charging could potentially appear on public transport networks.
how does it work?
When you use a device that supports wireless charging you simply need to place it on a charging pad to charge – no cables required. For mobile device owners such solutions reduce the problems of finding a spare cable or plug. Early examples include the Palm Touchstone, which was released in 2004.
Wireless charging uses two resonant inductive couplings to transmit low-power signals between two devices, one inside the charger the other inside the device. When the coils are close enough they create a magnetic field and the charging process begins.
The tech is only really suitable for smaller mobile devices. The Wireless Power Consortium (developers of Qi) currently only supports 5-Watt transmitters, with transmitters up to 15-Watts “in production” – you can’t effectively charge your laptop, at least, not yet.
Barriers to mainstream deployment of wireless charging solutions have included relatively low power efficiency and competing standards.
Low power efficiency means that only around 80-85% of the power is sent to the device (Qi), with the rest wasted. The WPC is working to improve that percentage this year, along with extending charging power to 15W and charging distance to 45mm.
no unified standard, yet
The lack of a clear standard also inhibits market evolution. Manufacturers hoping to bring solutions to market have four choices:
· Wireless Power Consortium’s (WPC) Qi
· Power Matters Alliance (PMA)
· Alliance for Wireless Power’s (A4WP) Rezence
· Or a self-developed proprietary solution
(This complexity will be reduced now PMA and A4WP have announced plan to merge).
While we wait for a clear standard to emerge it is likely some manufacturers will support multiple standards in their products. IHS anticipates solutions supporting multiple charging standards will account for 30 percent of the market by 2018.
IDC mobile-phone analyst William Stofega believes Apple, like many, will be waiting to see which wireless standard gains critical mass before committing to it. Apple is currently recruiting staff to help bring wireless charging solutions to its “mobile platforms”.
The silicon required for multi-standard support will be available from the usual Asia-Pacific component makers, including MediaTek, RichTek and ENE Technology. Samsung has opted to use both Qi- and PMA- standard tightly coupled inductive charging in its products, while Apple uses its own proprietary solution.
“End users do not care which technology or standard their device uses, they just want it to work well,” IHS's Green says.
Further out and it seems likely we will see wireless charging solutions that charge objects up over a distance. Intel and Toyota are supporting a Rezence-based specification called WiTricity, which will charge devices at much longer distances. If used with repeater hubs you could create offices in which every object was powered wirelessly using this solution. You walk into that office and your smartphone will start charging up wirelessly.
Meanwhile if you use a device that doesn’t support wireless charging you need to invest in peripherals that do, such as the Powermat ring solution (compatible with iPhones and some Android devices). Plug this into your device and you’ll be able to use a Qi-based wireless charging mat in your local Starbucks.