BMW has a couple of genuine hits on its hands with the all-electric BMW i3 and the BMW i8 plug-in hybrid (PIH) sports car. Not very far behind will be more plug-in hybrids, as we have seen PIH versions of 3 Series, 7 Series, and X5s in various degrees of testing camouflage. These vehicles need to be charged and so far, the technology to do so requires the vehicles to be tethered to a wall or post charger. Maybe not much longer, though.
Even though BMW has pioneered sophisticated charging stations for home and work use that can be integrated with the power grid, the car, and smartphones, the company is looking beyond these to make the charging experience even better for its customers.
Inductive charging of high-voltage batteries may be the next step and BMW is charging ahead with this concept. According to a recent press release, “The development objective in the medium term is to put reliable, non-wearing and user-friendly solutions for inductive charging into production that have been tailored to both the batteries in the BMW i cars and the high-voltage batteries in future plug-in hybrid models from the BMW Group.”
Inductive charging is better—or at least different—in that a physical cord connection to the charger is not necessary. A primary coil on the floor of the parking space transmits an alternating magnetic field between it and a secondary coil located in the vehicle’s floor. With an efficiency factor of over 90 percent, the car’s batteries can be charged safely and conveniently just by parking and pushing a button.
The goal is to develop enough charging power—say, 3.6 kilowatts—to fully charge a plug-in hybrid vehicle in under three hours. In fact, prototypes have charged the batteries of a BMW i8 in less than two hours. All-electric vehicles like the i3 would require more charging time so part of the development would address a goal of fully charging an i3 overnight, perhaps by increasing the power to up to 7 kilowatts.
As with the current BMW I Wallbox charging station, inductive systems could be activated and monitored from a smartphone.
It’s obvious BMW is serious about this next-generation technology, to the extent that they have signed an agreement with Daimler for the joint development and implementation of a standardized inductive charging system. And we would guess that where BMW and Daimler lead, others will be sure to follow.—Scott Blazey
[Photos courtesy of BMW AG.]