Evatrans Plugless Power Makes EV Charging as Simple as Parking

The two-part system, based upon the principle of inductive charging, works without any operator involvement. A driver can park his vehicle in a Plugless Power equipped parking space and walk away, as the system automatically begins charging the vehicle.

Evatran, LLC, is a clean technology subsidiary of Virginia-based MTC Transformers, and wad founded by MTCs owner, Tom Hough, to take advantage of that companys expertise in transformers and power-transfer technologies.

Evatran, LLC, is a clean technology subsidiary of Virginia-based MTC Transformers, and wad founded by MTCs owner, Tom Hough, to take advantage of that companys expertise in transformers and power-transfer technologies.

Inductive charging technology employs an electromagnetic field across a short distance, in stead of direct contact between wires, to transfer electricity. This type of close-proximity wireless charging should be familiar to most: if you own a Phillips cordless toothbrush, this is what happens when you place it in its charging base.

Evatran, like the toothbrush, uses two inductive coils: one in the parking base, and one mounted in the bumper of the car (currently an add-on unit). When the coils are close enough to each other, electricity coming out of the tower unit generates a strong, alternating, magnetic field in the parking base coil, and this, in turn induces electrical current in the bumper unit coil, which continues on to charge the battery.

I found it interesting to that Plugless Power, like the other charging systems announced, looks sort of like a really big iPod, with an iPod-colored cement parking block at its feet. There is very good reason for this design. According to Mr. Hough, one of Evatrans marketing strategies is to make their products easy for customers to use and adopt. They do this by employing design elements that customers are familiar with, and designing in usage patterns that are similar to habits that customers already have.

For example, customers already know how to deal with a parking space with this type of object at one end. It practically screams at you pull up close, and make your wheels touch the curb, which is exactly what you need to do to be close enough to charge.

The upright part of the unit, on the other hand, is friendly and familiar, but in a different way. The large, obvious icons light up in various ways, to let you know if the system can engage or not.

Its easy to imagine where this might turn into a back-and forth struggle, having to precisely position the car just right; a special kind of pain that most people normally associate with parallel parking. However, this is not the case. The Plugless Power unit utilizes a small motor and pulley system, built into the base section, that precisely positions the charging transmitter.

Instead of forcing the customer to learn something new, foreign and potentially dangerous (at least in their minds), this type of design removes as many of the concerns as possible, and should help speed up the adoption of Plugless Power, and , perhaps, EVs, as a whole.

One small dark cloud in this mostly sunny outlook is the fact that inductive charging, by its very nature, is less efficient than wired charging. Although Evatrans current prototypes are getting efficiencies in the 80% range, the company does not plan to release a product unless they have achieved 90% efficiency or above.

Evatran will be releasing their products in December, right around the time that Chevy Volts and Nissan LEAFS will start being delivered. However, the product being delivered in December will actually be a charger that has a plug (yes, you read that right), and not the inductive charging component. True Plugless Power plugless charging products without the actual plugs (say that ten times fast) will actually be available in April of 2011.

Early-adopters, who wish to get on board in December, will be able to do so for around $3,000. They will be able to add the inductive charging by purchasing an $800 upgrade in April, when the units become available.
According to a company representative, this $3,800 total price will be a discount over the price of the final proximity units.

While it seems like the Plugless Power concept should be a hit with EV buyers, the loss of efficiency might be a deal breaker for purists.