Without a doubt, the most frustrating thing about owning a smartphone or mobile device in 2015 is how long it lasts on a single charge. While improved power management has led to some advances, these have been counterbalanced by the slow development of new battery technology and the desire for ever-smaller, ever-thinner gadgets.
It’s why wireless charging must rank as the most eagerly-anticipated phone innovation since engineers first combined a PDA and a mobile phone into one device.
Wireless power goes all the way back to Nikola Tesla
Wireless charging technology, which is also referred to as ‘inductive charging’, works by sending energy between two objects using an electromagnetic field. It was first demonstrated by Nikola Tesla in 1891, when the inventor showed that it was possible to light electric lamps without the need for wires.
An early example of the technology being used in earnest was a crystal radio which used the power of the radio signal itself to transmit a charge to accompanying headphones. In 2009, the low-power Qi industry standard was revealed, established by a consortium of interested parties referred to as the Wireless Power Consortium.
To date, some smartphones like the LG G4, Google Nexus 6 and key Nokia Lumia handsets have Qi technology built in and a number of establishments such as McDonald’s and Starbucks have began offering wireless charging facilities to their customers.
However, there are still hurdles to overcome. Wireless charging is more expensive than plugging in a power lead, since it requires extra components that drive up the cost of manufacturing.
It can also be slower than mains charging and, perhaps most damning of all, is the fact that — unlike mains charging — wireless charging actually makes it more difficult to use your device while it is charging. This is because the handset must be kept in contact with a charging pad (or in Qi’s case, within 4cm). The result is a technology that, while extremely promising, has not yet reached mass adoption.
Fortunately that is starting to change. Companies such as Energous, Nikola Labs and Intel are working on technology that will allow users to charge devices over the air.
WattUp converts Wi-Fi and cellular signals into energy
The Energous WattUp technology works thanks to a special antenna, which converts cellular and Wi-Fi radio waves into a packet of low-power energy. This can then be picked up by phones and converted into DC power for charging, say, a smartphone. For the first time, this technology is considered to be safe in a way that it never has been previously.
Nikola Labs takes a similar approach, integrating “radio frequency harvesting technology” into phone cases for the iPhone 6 and Galaxy S6. The cases recycle wasted RF energy (see below) from Wi-Fi, Bluetooth, LTE, 4G and 3G signals to extend a phone’s battery life.
Intel, meanwhile, is working on a wireless charging technology based on the Rezence standard developed by the Alliance for Wireless Power (A4WP). Intel’s next-generation Skylake processors will support this near-field resonant technology, enabling future laptops to charge without being plugged into the mains.
It’s part of Intel’s plan to make laptops completely wire-free.
There is still plenty that needs to be done to get the industry to adopt wireless charging as a standard. But for the first time in history it’s looking like we may finally be on the verge of putting those pesky charging cables away for good.
Without a revolution in battery technology, this could be the solution we’ve been searching for. — Luke Dormehl (@lukedormehl)