Players tell

With the gradual acceptance of electric vehicles by more people, it also seamlessly connects the job responsibilities of fuel vehicles in family life.

Especially for those European and American users who have the habit of touring cars, electric vehicles naturally undertake the work of tractors.

But for the electric vehicle as a tractor, the embarrassing problem that the owner may encounter is to stop and charge in the middle. If they go to some sparsely populated places, they may not find one and a half charging piles.

In order to avoid this kind of trouble, even those car owners who plan to tow their RV to the suburbs only once or twice a year must buy an electric car with the largest battery capacity.

This means that in the next year, they will drive on urban roads with heavier batteries, which are not needed in daily commuting or traveling without trailers.

E. prototype of electric trailer for family RV

Semi-trailer has its own power.

Dethleffs, a German travel trailer and RV manufacturer, believes that building an electric trailer and adapting it to the connection of various tractors may make itself a game changer, especially for some customers who just want to rent a trailer for fun.

With the help of ErwinHymer, a travel planning company, and ZF, an auto parts supplier, the company designed and developed a prototype trailer called E.HomeCaravan

The total length of the test line is 386 kilometers.

In order to prove that their electric trailer can really meet the needs of long-distance travel, Dethleffs took a route across the Alps last month, with a total mileage of 386 kilometers, which is also a very popular route among European RV owners.

During the trip, they chose an Audi E-TronSportback with a cruising range of 350 kilometers and equipped with EPA as a tractor, and used it to drag a large travel trailer across the entire planned route without charging at all.

This route starts from the company's factory in Isny, Germany, passes through Brenner Pass, and finally reaches the northern bank of Garda Lake in Italy.

The acceleration provided by the electric trailer system is equivalent to that provided by E-Tron alone, and is calibrated to enhance stability.

It should be pointed out that due to the slow speed of mountain roads, it took them more than six hours to run the 386 kilometers.

On some journeys, E-Tron and the trailer drove against strong headwinds. Because the 82kWh battery pack of E-Tron and the 74kWh battery pack of the trailer provided sufficient power, they finally reached their destination safely.

There are two battery packs on the front and back of the trailer axle.

E.HomeCaravan's prototype itself is equipped with two battery packs, each with a power of about 40kWh, which are placed at the front and rear of the axle respectively.

In addition to providing the necessary power, these two batteries can also provide electricity for other camping needs or support solar cells on the roof.

In terms of charging, the AC charging power of the trailer is 7.2kW, and the DC fast charging power can reach 50kW.

The rear of the car is provided with a safety collision protection structure.

The battery pack of the trailer is placed in the inner frame, while the outer frame contains the inverter, the charging unit and the control unit.

In view of the collision safety of the battery pack, Dethleffs also specially set up a honeycomb collision protection structure at the rear of the vehicle.

The company said that the structure has completed various simulation tests of stability and reliability.

The production version of the electric trailer will further reduce the weight.

The battery and drive system add up to about 600 kilograms of trailer weight. Although Dethleffs does not clearly indicate the total weight of the electric trailer, it should be within the rated traction weight of Audi E-Tron 18 14kg.

Dethleffs thinks that the weight of the trailer still has room for optimization, and says that the future production version of the electric trailer will be reduced to about 400kg, which is much lighter than the battery pack of its tractor E-TronSUV, which weighs 765,438+04kg.

The drive unit of electric trailer is developed by ZF, and has two offset motors. The continuous power of each motor is 30kW, the maximum power is 90kW and the maximum torque is 89Nm.

Just like the electric car we are driving now, when the vehicle slows down, the motor of the trailer will also perform gentle regenerative braking and store the generated energy in the battery pack.

The main function of the trailer system is to keep

Constant traction load on the traction rod

Future solutions

The most complicated part of the electric trailer system may be the active traction load function of its mobile control unit, which is only responsible for providing enough thrust for the trailer to maintain a constant traction load on the traction rod.

The original intention of the design is to let the tractor tow the trailer with relatively low power, recover the regenerative braking energy when the trailer goes downhill, and be responsible for detecting and compensating the crosswind or turning.

Dethleffs thinks that E.HomeCaravan is a meaningful "future solution", which is not only useful for electric vehicles, but also useful for fuel vehicles, because it can make fuel vehicles with less power pull more loads.

The trailer is equipped with an intelligent parking application.

Another advantage of this electric trailer is that its parking system based on smartphone APP can accurately guide the trailer to its parking space, which is easier than backing up with a trailer.

Unfortunately, as a prototype, E.HomeCaravan is not legal in Europe. However, with the support of the German Federal Ministry of Transport and RV Company, it will receive more tests one after another.

Perhaps in the near future, the production version of electric trailers optimized by Dethleffs will appear on various rural roads in Europe. Of course, if it wants to enter the American market, it will also face similar certification challenges.

Electric travel trailer developed by airflow

Finally, Dethleffs is not the only company involved in electric trailers.

In February of this year, Airstream, a trailer company in Ohio, said that it was developing electric travel trailers.

Last year, electric car startup LordstownMotors announced a partnership with RV travel service company CampingWorld. It plans to produce electric trailers as early as 2022, and then produce electric RVs.

In short, just as electric cars replace fuel cars, electric trailers may soon replace traditional trailers.