Wireless charging mat - Nissan Leaf
If you're thinking about making the transition to an electric car, one of the more daunting aspects about ownership might be the idea of plugging in. Although stepping out in the rain to hook up a public charger is arguably a lot safer than the gasoline you might have dripped on your fingertips, it might still be hard to sway some.
To that end—and to make charging even more convenient—Nissan is working on an inductive (wireless) charging mat for the Leaf that should make charging a matter of simply backing into a parking spot, and hitting a screen prompt to verify that you'd like to charge. Just as in the charging mats that are currently so popular for smartphones (or electric shavers or toothbrushes), the mat system uses magnetic induction charging technology. The only change to the Leaf itself is a small receiver added to the underside of the Leaf—roughly below the back of the battery and between the rear wheels.
Interface for Nissan Leaf wireless charging mat
As fast as typical plug-in charging units
The system, which is completely sealed, waterproof, and weatherproof, will charge the Leaf's battery to full in about eight hours—about the same time as has between 80 and 90 percent efficiency—so comparable to 240-volt home and commercial systems. The indirect magnetic induction mat has an “optimized coil and circuit design,” and would be affixed to a garage floor, also requiring a permanently installed charging station alongside.
How much will the unit cost? Nissan officials wouldn't say; although they agree that cost is still prohibitive, they anticipate that with volume it could be in the same order of magnitude as home-charger installation—so, to speculate, likely well under $10,000, or perhaps less than $5,000.
Want to buy one? Be prepared to wait three years or more
If you're excited at the possibility, you'll have a potentially long wait to get one in your garage. The inductive charging mat is “still at the early stages of development,” engineers said, with two to three years until its fleet-test stage.
Even once the unit is ready for prime time, Nissan officials admit that legality will be an issue. In Japan, inductive charging at this level isn't yet permitted; and in order to approve it, studies may yet have to be done to verify that there are no issues with medical equipment or communications interference. In the U.S., the process might be easier, as there were hundreds of now-obsolete paddle-based inductive chargers installed in California in the 1990s. Bringing the device down to ground level could create new regulatory issues.
Nissan plans to limit testing to a fleet that's pressed into home use first, then test the units in more frequent, varied public use. Ultimately, the automaker would like to see them installed in a number of bays in parking buildings.