While electric vehicle charging networks continue to evolve and expand, there is another approach to reducing range anxiety: taking the charger with you. The EP Tender range-extender system is designed to give an extra lease of life to EV batteries with the addition of a trailer mounted generator system.
Applying the same principle that we've seen in the ebuggy and Rinspeed Dock+Go concepts, the EP Tender portable charging system is essentially a mobile commercial generator that's been pared down for consumer use. The 200 kg (440 lb) system utilizes a trailer mounted 600 cc engine that resides in standby mode until a low charge signal is received from the vehicle. While the vehicle is being driven, the tethered trailer activates the generator, which in turn recharges the EV battery. The idea is that this charge on the go system could negate the need for lengthy charging stops.
Currently under development in France, the system can generate up to 22 kW of power during a cycle at speeds up to 130 km/h (80 mph). The company is also working on developing a 35 kW system using a 900 cc engine. Depending on the vehicle EP Tender reports a range of 600 km (360 miles) could be achieved using the charge to go system. But there is a hitch. As Autobloggreen points out, main stream EVs aren't necessarily designed to be charged while in motion, which adds an extra level of complexity to the equation.
EP Tender's portable charging system is still in its early testing stages, with similar systems for electric motorcycles and hybrids reported to be in the works.
Source: EP Tender