Earth Protect Blog

Plug-free charging — it’s been the holy grail for cell phone, laptop and gadget makers for years. And now it’s fodder for the plug-in vehicle crew. On Tuesday at the Plug-In 2010 conference in San Jose, Calif., a company called Evatran unveiled its “Plugless Power” electric vehicle charger, which will eventually use “proximity charging” technology to charge up electric vehicles.

The Plugless Power unit works via the combination of a parking block installed on a garage floor or parking lot, a connected tower that detects if the car is charging (and also has a cord option), and finally a unit installed underneath the bottom of the car itself. The parking block and the device installed under the car wirelessly connect when the car drives over the block, and the battery starts charging.

It’s not exactly wireless charging, where power is broadcast over the air, but it’s proximity power charging, where the devices need to get close enough to induce a charge through the short air space. Proximity charging most often uses magnetic induction, where two magnetic coils — one inside a charging pad and one inside a device — connect to allow a charge while the device is sitting on the pad (here’s 10 Things to Know About Wireless Charging).

Cell phones, gadgets and laptops have been the focus of much of the innovation behind this technology, but increasingly automakers and plug-in vehicle charging companies have been working on the tech. Last year Nissan told the UK Guardian that it has already worked wireless charging into the design for its all-electric vehicle, with the goal to ultimately make charging quicker and easier than it is with today’s cords and plugs. Evatran says it has had interest from several major automakers.

The lack of efficiency of the power transfer has been the big road block for magnetic induction. As Stacey on GigaOM recently pointed out, efficiency rates commonly range from 50-70 percent using magnetic induction, and can transfer 5 watts of power, according to Menno Treffers, chairman of the Wireless Power Consortium.

An Evatran spokesperson told me that their proximity charging uses an enhanced version of magnetic induction that makes the charging very efficient. Currently the prototypes are getting just under 80 percent efficiency says Evatran, but the company says it will only bring a product to market with 90 percent efficiency.

However, there’s a significant caveat to Evatran’s “launch.” The company will only have charging units with plugs (and not the proximity charging) available for order starting in December 2010. By April 2011 Evatran says that its plug-free chargers will go on sale and anyone who has bought a plug-in charger before that date can upgrade the unit for the plug-free kind. The plug-in units will go on sale for around $3,000 and the proximity upgrade (which is discounted for those that pre-order the cord units) will cost $800. So by April 2011 you can buy one of these systems for $3,800.

Evatran says it hasn’t yet priced how much the plug-free units will cost (without the discounted upgrade) upgrade starting next April. The chargers are Level II, 208/240 VAC, and the plug option is the standard SAE J1772 compliant.

While some people are worried about the effects of electromagnetic radiation flowing through the air, Evatran says the set-up is safe. The PR team invited me to lay on the charging pad, and throw snow on it.

I had actually never heard of Evatran before this launch. According to local Virginia news the Wytheville, Virginia-based Evatran is a spinoff from MTC Transformers a company founded in 1985 that makes specialized electrical transformers for niche markets. Evatran was started in April 2009 and is supposed to spin out of MTC this month.

At the end of the day, the plug-free electric vehicle charging industry could be substantial and wireless charging is already starting to become more mainstream for gadgets. Global shipments of gadgets capable of proximity charging are estimated to jump nearly 70 times by 2014 from the 3.5 million units expected to sell this year, according to research firm iSuppli. More than 234 million such consumer devices with wireless charging are expected to be shipped over the next four years, including cell phones, media players, digital cameras and small computers, with initial adoption coming from cell phones.