Anyone who used to pack battery-operated devices such as the portable cassette player would be happy to take a set of spare batteries with them. It would also be practical for an electric car. The spare battery is a bit large to put in your pocket. But moving on is possible: That French company EP Tender has developed a battery hanger for electric cars.
A battery with a capacity of 60 kilowatt hours is installed in the trailer. It is intended for the Renault Zoe, whose own battery has a capacity of 52 kilowatt hours. The car can travel about 390 kilometers. The range would more than double with the trailer – it acts like the tender of a steam locomotive.
The idea is not entirely new: in 2011, the Swiss car refiner Rinspeed introduced an additional battery for the electric smart. Dock & Go was intended as a rolling battery pack that was to be attached to the back of the car. The US company Electro Motors and Vehicles had built a trailer with a combustion engine as a range extender a year earlier.
EP Tender started a few years ago with a combustion engine in its trailer. The company has also built and delivered around 20 units to customers who drive a Renault Zoe or an electric Renault Kangoo. In the meantime, the prices for the batteries have dropped so much that EP Tender focuses on battery trailers.
"We solve the problem of making electric cars that are affordable comfortable over long distances". said EP tender boss Jean-Baptiste Segard of the US automotive magazine Automotive News, However, the company does not want to sell the trailers, but rather rents them out: If the electric vehicle starts a longer journey, he books a trailer using the app, picks it up at a parking space, hangs it on his car and drives off.
At the destination, he puts it back in a parking space where it is loaded. If the trailer is not required, it can be used as a network storage. EP Tender is aiming for a rental price of just under 35 euros. The problem is that most electric cars currently do not have a trailer. However, EP Tender says it is negotiating with Renault and the Groupe Peugeot Société Anonyme (PSA), which includes the Citroën and Peugeot brands, to equip their electric cars with a trailer hitch and a plug. The necessary approval should be granted in 2022.