A caravan kills the range of every electric car. Unless the caravan has its own electric drive. On a record drive with the caravanning colleagues.
No matter how quickly electric mobility develops in terms of sustainability, range and charging speed: When heavy loads come into play, it gets exhausting. A caravan melts even the range of vehicles with huge batteries faster than a ball of stracciatella in the Italian sun. But that's exactly where our colleagues from the Caravaning magazine wanted to go. From Isny in Allgäu to Lake Garda. With a caravan and an Audi E-tron 55 quattro. It has a battery with usable 83.6 kWh between the wheels and should, according to Audi, cover a maximum of 411 kilometers. The route to Riva del Garda could theoretically be mastered. But definitely not with a caravan in tow. At least not with an off-the-shelf caravan.
Almost 400 kilometers and 4,870 meters in altitude
But the situation is different with the prototype E-Home Coco , which Dethleffs, the Erwin Hymer Group and the joint development partner ZF put on wheels. The world's first e-caravan, i.e. a caravan with its own electric drive. Another prototype, but mature enough to make it across the Alps. With you every kilometer: Ingo Wagner, the editor-in-chief of the trade journal Caravaning (Reportage: The record drive on www.caravaning.de ). The mission: The electric car and trailer must not be recharged on the almost 400-kilometer route, on which 4,870 meters of altitude have to be overcome. Only a non-stop holiday trip with a caravan is an accolade for long-distance electric transport and able to take a little wind out of the sails of skeptics.
Leading instead of pulling
And that worked, apart from a short stopover due to an error message triggered by an inverter. When the record drivers with E-Tron and E-Home arrive at the company premises of ZF's marine department in Arco (it's only five kilometers to Riva del Garda), the screens still show battery levels of 19 and 22 percent. This would mean that the E-car combination would go much further than Lake Garda. The subsequent data analysis shows how well the prototype performed. At no time did the Audi have to pull more than 20 kilograms. So he was driving the trailer rather than pulling it.
2x40 kWh battery under the caravan
This is made possible by a newly developed drive unit with a strain relief module in the trailer hitch. The traction force sensor integrated in it registers whether the towing vehicle is accelerating, decelerating or rolling evenly and passes this information on to the motors. Within a tenth of a second, they provide just enough thrust at speeds of just over 100 km/h so that a certain trailer load is not exceeded. The two synchronous motors (one per wheel) can each release up to 90 kW (122 hp) for short periods. Braking is almost exclusively by recuperation. If you have to take a break, you can charge the caravan (2x 40 kWh) with fresh energy using the fast charger.
Even if it will still take three to four years until it is ready for series production and the technology still has to be significantly slimmed down in favor of costs and weight, the record drive shows that the concept of the e-caravan is actually a way into the electrically mobile travel future can be.