With wireless charging now becoming ubiquitous with Samsung, Apple and others embracing the tech with various smartphone models, it's interesting to note many major gadget makers have gone with the Qi standard. But it wasn't so long ago that the rival PMA standard, championed by one-time market leader Powermat, was leading the charge. But with Powermat joining the Wireless Power Consortium, we are now moving on from wireless charging's version of VHS vs Beta or Blu-ray vs HD DVD.
Now that Apple has brought their ecosystem over to the Qi side of the fence, it seems that the market has spoken and Qi is THE preferred standard for wireless charging. Even IKEA is integrating it into their furniture.
Although Samsung included both PMA and Qi in the Galaxy S6, that was a short-term solution while the market sorted itself out, much like the movie business includes Blu-ray, DVD and digital versions of movies for many releases as the market settles around a preferred format.
Both Qi and PMA are inductive charging technologies. They differ in the transmission frequencies they employ and in how communications for connecting devices to chargers are executed but, otherwise are quite similar. PMA offers some benefits over Qi, such as the ability to log how long a user spends charging a device.
For now, Qi seems to have won the day although there are further improvements to wireless charging on the horizon.
The Energous WattUp uses radio wave based technology that can charge devices at distances of up to five metres from a charging hub. The extra range is Energous’ big selling point although changing efficiency diminishes as you get further away. It's the kind of tech I can see being used for keeping TV/home theatre remotes topped up in a lounge room rather than for charging smartphones and other communications devices that require a lot more juice.
But, as the tech improves, it might usurp Qi one day.