BMW has been working on wireless charging since 2014. Now, it says it will begin offering it on production cars, starting with the 530e iPerformance beginning in July according to Car. Wireless charging will be available on that model in California later this year as part of a one-year pilot program, according to AutoBlog. While BMW says the system is compatible with most of its plug-in hybrid offerings, it is unknown at this time what other BMW models will offer the wireless charging option or when.
Wireless charging involves a base pad that can be mounted in a garage or outdoors and a secondary coil mounted to the underside of the vehicle, usually at the front. “An alternating magnetic field is generated between the two coils, through which electricity is transmitted without cables or contacts at a charge rate of up to 3.2kW.” according to a BMW press release. “This form of power supply to the high voltage battery is extremely convenient for customers and involves a charging time of around 3.5 hours.” Normal charging using Level 2 equipment takes about 3 hours.
BMW incorporates a graphic display built into the infotainment screen to guide drivers to the “sweet spot” where maximum charging can take place. Once the car enters a green circle, the equipment is properly aligned. As soon as the car is turned off, charging begins. The system is internet-enabled, so the owner can be check on the charging progress at any time.
A built-in proximity sensor interrupts the flow of current if any cute furry things get lodged between the two components and the owner will get a notification that charging has been interrupted via a smartphone app. BMW says the level of electromagnetic radiation is less than from a normal kitchen hot plate, a device many in the UK use to warm up their steak and kidney pie in the evening.
The purpose of wireless charging is convenience. With it, a driver can start every day with a full battery without having to plug in a charging cable. It’s like having someone slip into your garage overnight and fill your tank with gasoline. If your PHEV has enough range to meet your daily driving needs, you may never need to visit a gas station again.
Wireless charging is not for rapidly replenishing a battery while on a cross country trip. It is for making driving an electric car more user friendly. Drive it. Park it. Start the next day with a full battery. Doesn’t get much more convenient than that.
Honda and Hyundai are both working with WiTricity on wireless charging systems with double the charging power of the BMW system. People are willing to pay more for convenience, but at this moment there are no firm figures on how much wireless charging adds to the price of a vehicle or how much more expensive wireless charging units are than convention wall chargers.