The idea is ingenious, evidently inspired by what is done today with smartphones that have limited electrical autonomy, but that can be extended thanks to the power banks, i.e., the external battery packs. EP Tender, a French startup, has transferred this solution to electric cars.
The company is developing a mobile charging trailer that can tow any electric vehicle and keeps your on-board battery topped-up on the go. The EP Tender is named after small boats on yachts that effectively serve the passengers of large boats. The company wants to set up rental battery shops for those who want to make long trips in their electric vehicle.
Drivers of electric vehicles will have nothing more to do than “connect” the trailer-battery to the back of their car and then take advantage of the 60KWh provided by the complex trailer. Once used, the charging-trailer is left at the points designated by Ep Tender, where it can be charged and always ready for use with their batteries charged.
The trailers have a special design so that they do not cause aerodynamic resistances and have small wheels to reduce their friction on the asphalt.
The cost of the rental – evidently corresponding to the use of the charge – should be a maximum of €34 ($37). At the moment, many electric cars are not approved for towing, but EP Tender estimates that this will change by 2022. It will cost €600 (about $650) to install this special towbar and connection.
The target price for each trailer set by the company is €10,000 (about $11,000), and its business plan provides profitability by 2024, with the rental of 4,150 trailers to 60,000 customers.
The French startup has already developed another variant of the ‘power bank’ trailer, in this case, destined to transform 100% electric cars into hybrids. In the same towed vehicle, instead of the 60 kWh battery, a 22 kW (30 HP) thermal unit powered by a 35-liter tank, which guarantees an additional electric range corresponding to 80 kWh, therefore with a consumption of 0.5 liters per 100 km.
The project has prospects as it greatly increases the autonomy of electric cars with low rental costs, and of course, the charging of the batteries is done by an original trailer-power bank.