If you listen to the ad executives trying to sell the 2011 Chevrolet Volt there’s one big problem with electric cars: they don’t go as far on a charge as a gas car can on a tank of fuel. 

While it’s true that electric cars like the 2011 Nissan Leaf and 2011 Coda Sedan may provide more than enough range per charge for the majority of users we do get asked time and time again what happens when you need to go further?

We’ve covered fast charging here, along with a car which can go a massive 375 miles on a single charge. Continued use of fast charging can reduce battery pack life, and large battery packs mean less efficiency and more cost to the end user. 

But for those who need an occasional solution a firm in Indiana claim to have a solution that offers a third option - a range-extending trailer.

Tow-Along Solution

Enter the unimaginatively named Electric Motors and Vehicles Company (EMAV) with its two-along Power Regeneration Unit (PRU). 

Looking a little like a shrunken camping trailer, the PRU holds a 70 kilowatt-hour battery pack along with a small gasoline-powered generator. Theoretically, this could extend the range of cars like the 2011 Nissan Leaf by several hundred miles. But just like the 2011 Chevy Volt, as soon as the battery is depleted power is generated by gasoline - a solution many EV owners will not want to use. 

Generator/Pusher Trailers Aren’t New

Believe it or not, the concept of a generator trailer behind a battery-powered electric car isn’t new. do-it-yourself converters of electric cars have often looked towards trailers as a way of carrying around extra batteries and/or a gasoline-powered generator. 

Some enterprising individuals have even gone further, finding a donor front-wheel drive car like an early 1990s VW Rabbit with a sound engine and automatic transmission to convert into a pusher trailer - a trailer with powered wheels that can push an EV along from behind when the batteries are flat.

Hardly Efficient

Cars like the 2011 Nissan Leaf have been carefully designed to produce as little drag as possible when moving through the air. Carefully designed headlamps, aerodynamic radio antennae and even smooth door handles reduce the energy needed to push the car along. 

Towing a trailer, however well designed, consumes extra energy. Expect an EV towing a trailer to use its on-board battery pack far quicker than it would without a trailer. 

Void Your Warranty

We’re not sure how EMAV plan to offer this solution on cars which normally don’t have a  hitch as standard.  

While laws vary from state to state and country to country, fitting a hitch  to a car which isn’t designed to have one can void warranties and invalidate your insurance.  Installing a hitch and making use of a solution like this could leave you with a bill for thousands of dollars in case of accident or breakdown. 

Only A Prototype

While EMAV has previously built a successful trail-rated camping trailer which is sold as an off-road accessory in Chrysler Jeep retailers nationwide, this is the first time the company has worked with electric vehicles. 

Screenshot of EMAV's website.

Screenshot of EMAV's website.


EMAV says it offers a range of rugged electric vehicles, but we can’t find any details of them.  

There’s little we can find out on the PRU either, other than it having several patents pending on it. 

EMAV’s website is no more helpful. When we visited it earlier today we found the homepage to be an image of what the site may perhaps look like rather than an interactive website, indicating a website in the very early days of development - and far from a finished corporate website. 

For now our only conclusion is that the EMAV PRU is a long ways from commercialization, despite the promise to bring it to market by early 2011. 

Is it vaporware?There's no price, no release date and no technical information. We're supicious at present. But our honest solution for anyone needing extra range out of their electric car is to hire a plug-in hybrid or fuel efficient car for the days when 100 miles really isn’t enough. It’s likely to cost far less than this cumbersome tow-along.