Scaled-up electric toothbrush technology could wirelessly charge electric cars, says Volvo
The Volvo C30 plug-in takes 2.5 hours to chargeAn electric car is already more convenient to 'refuel' than gasoline and diesel vehicles: You simply plug it in overnight, and the battery is always full when you leave in the morning. You don't have to stop somewhere to charge up unless taking a long road-trip. But things might get even more convenient, at least for those who park their EVs or plug-in hybrids in the same spot most of the time. Volvo has been studying the application of inductive charging technology, which is used in electric toothbrushes, for example, with an electric version of its C30.
“With inductive charging, you simply position the car over a charging device and charging starts automatically. We believe that this is one of the factors that can increase the customer’s acceptance of electrified vehicles,” says Vice President, Electric Propulsion System at Volvo.
Of course, inductive charging won't beat the efficiency and capacity of simply plugging in cord, but the extra convenience might be a selling point for places like private garages where time is not of the essence. If you stop at a fast-charging station in the middle of a road-trip, speed matters. But if you park your car somewhere overnight, it doesn't matter as much if it takes many hours to fully charge.
Inductive charging uses an electromagnetic field instead of a cord to transfer energy between two objects. An induction coil creates an alternating electromagnetic field from a charging base station. A second induction coil in the portable device picks up power from the electromagnetic field and converts it back into an electrical energy that charges the battery. This technology is common in electrical home appliances such as electrical toothbrushes but is not yet commercially available to charge electric cars. (source)
This research begun a few years ago, as we then reported.