Original URL: http://www.theregister.co.uk/2012/10/08/qi_in_car/
Guidelines issued for Qi wireless gadget charging in cars
Worries over drivers stunned by flying plugless mobes
The Wireless Power Consortium has published its recommendations for plugless in-car charging, primarily aimed at ensuring key fobs don't warm up and that phones don't become projectiles.
Guidelines (pdf , as dull as one would imagine) from the custodian of the Qi wireless-charging standard require physical restraints on the thing being charged, and charging coils at lest 15cm from a pocket or purse, distancing the standard from the power-grazing model of its competitor for the sake of expediency in getting onto vehicle dashboards.
The Wireless Power Consortium's guidelines cover installations conforming to the standard, which uses coils embedded in device and charger to induce a charging current. The rules for cars mainly involve ensuring the charging device is clipped into place, but interference with immobilisers and AM radio is also a concern.
"Mechanical means should be provided to hold a device being charged from becoming a projectile under normal vehicle operation. Examples could be retention clips, charging area device cover or a recessed cavity" says the recommendation in borderline English.
More interesting is the concern about what Qi might do to a key fob:
"The transmitter should be installed at minimum 15 cm away from any possible layoff of the key fob, handbag or driver pockets", which removes the possibility of an in-door charger for in-pocket charging as espoused by the Alliance for Wireless Power.
The Consortium has always been about throwing one's phone in the desk/bedside/dashboard and having it charge, while the Alliance (perhaps just for the sake of differentiation) promotes the idea of in-situ charging so one never thinks about power (wired or wireless) ever again. But that model requires greater range, and obviously needs to reach into one's pocket.
But the Alliance hasn't even got a standard written yet, while the Consortium is tidying up details of in-car voltages and dashboard placement, important for all those Lumia-wielding executives even if they will have to clip their phones into place. ®