Automotive

Dethleffs puts a new spin on towing with an electric camping trailer that nearly drives itself

Dethleffs puts a new spin on t...
The E.Home Coco features an 80-kWh lithium battery and roof-mounted solar panels
The E.Home Coco features an 80-kWh lithium battery and roof-mounted solar panels
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Dethleffs presents the world's first electric caravan
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Dethleffs presents the world's first electric caravan
An electrified caravan could help cut the load on small, electric tow vehicles like the BMW i3
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An electrified caravan could help cut the load on small, electric tow vehicles like the BMW i3
The E.Home Coco has a 40-kW electric motor on each end of its axle
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The E.Home Coco has a 40-kW electric motor on each end of its axle
A peek at the motorized E.Home Coco wheel
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A peek at the motorized E.Home Coco wheel
Dethleffs has built the battery into the floor of the caravan, keeping weight low and centralized
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Dethleffs has built the battery into the floor of the caravan, keeping weight low and centralized
Dethleffs reveals the E.Home Coco on the opening day of the 2018 Düsseldorf Caravan Salon
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Dethleffs reveals the E.Home Coco on the opening day of the 2018 Düsseldorf Caravan Salon
The Coco is one of Dethleffs latest trailers, a distinctive compact caravan with lightweight construction
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The Coco is one of Dethleffs latest trailers, a distinctive compact caravan with lightweight construction
Dethleffs reveals the E.Home Coco on the opening day of the 2018 Düsseldorf Caravan Salon
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Dethleffs reveals the E.Home Coco on the opening day of the 2018 Düsseldorf Caravan Salon
The E.Home Coco features an 80-kWh lithium battery and roof-mounted solar panels
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The E.Home Coco features an 80-kWh lithium battery and roof-mounted solar panels
Dethleffs intends to further test the E.Home Coco next year
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Dethleffs intends to further test the E.Home Coco next year

Last year, Dethleffs shook up the motorhome world when it debuted the E.Home concept, an all-electric motorhome covered in solar panels. At that very same Düsseldorf show, it revealed the curvy, lightweight Coco caravan concept. Fast-forward a year, and Dethleffs has smashed those two concepts together to create the E.Home Coco, a small, stylish concept trailer with a floor-mounted lithium battery and a dual-motor axle designed to decrease towing demands, add mobile power capabilities and provide handling advantages on the highway and at camp.

An all-electric motorhome makes immediate sense, even if the battery technology isn't quite there to make it more than a concept just yet. Replacing a loud, emissions-spewing gas engine with a quiet, emissions-free electric powertrain sounds like a much better way to get out and camp in nature. But a caravan doesn't have an engine to begin with, so why would you suddenly add electric motors?

Dethleffs believes that adding electric motive power to the otherwise passive camping trailer makes sense for a number of key reasons, so it's integrated a lithium battery skateboard-style into the E.Home Coco's chassis. At 80-kWh, it's no small auxiliary pack – it has more capacity than the the base-level Tesla Model S. The battery sends power to the electrified axle, which puts a 40-kW motor at each wheel. Solar panels on the caravan's roof help keep the battery charged.

Dethleffs reveals the E.Home Coco on the opening day of the 2018 Düsseldorf Caravan Salon
Dethleffs reveals the E.Home Coco on the opening day of the 2018 Düsseldorf Caravan Salon

The critical advantage of having a caravan spin its own wheels is cutting down the tow load on the vehicle out front. The E.Home Coco's intelligent control electronics manage the electric motors and cut the effective weight on the tow vehicle to a predefined number. So instead of towing, say, 2,000 lb (907 kg) worth of trailer, the tow vehicle is effectively towing a much lower amount of weight, which Dethleffs puts at 220 lb (100 kg) as an example.

Cutting the tow weight means that even a small vehicle with limited towing capacity can pull the E.Home Coco to camp. It also means that an electric car won't experience the devastating range cut that it would otherwise experience when towing a big, heavy trailer.

Each of the E.Home Coco's motors is capable of producing up to 347 lb-ft of torque, and the trailer is equipped with a torque vectoring system that can independently vary the torque delivery at each wheel for improved performance and stability.

The E.Home Coco has a 40-kW electric motor on each end of its axle
The E.Home Coco has a 40-kW electric motor on each end of its axle

The electric powertrain also helps out upon arrival at camp, and the E.Home Coco can maneuver under its own power, rather than requiring the vehicle to tow it into place. Using a smartphone app, the driver can easily park it into the designated camping space.

A large-capacity battery and roof-mounted solar panels could prove quite useful at camp, running standard electrical equipment like LED lighting, optional add-ons like air conditioning and heating, and accessories like tools, coffeemakers, blenders, etc, all without the noise or emissions of a gas generator.

Eventually camping season ends, and the typical trailer begins months upon months of taking up space and collecting dust. Not the E.Home Coco, which is designed to work the entire year. Dethleffs imagines it being hooked up to the home grid, its battery serving as a backup power supply or an active part of a solar system.

The E.Home Coco is part of Dethleffs ongoing research into more sustainable RVing. The company plans to test its effectiveness at cutting strain on the tow vehicle in the first half of 2019.

Dethleffs intends to further test the E.Home Coco next year
Dethleffs intends to further test the E.Home Coco next year

A pretty stylish, little trailer in its own right, the (non-electric) production Coco is on show right next to the E.Home Coco in Düsseldorf. We'll be taking a closer look at it in a forthcoming article.

Source: Dethleffs

12 comments
Malatrope
They have to be very, very careful with the control software, or this system will be dangerously unstable at highway speed. I am an engineer, and I had this idea in 1992. After studying it for awhile, I came to the conclusion the liabilities would not be worth it. The problem is uncontrollable secondary feedback. If anyone remembers, Mercedes attempted some years ago to produce a self-leveling industrial tractor-trailer ("semi") for use on sloped European roads. After some testing and realworld miles, drivers refused to use it because the entire trailer would start oscillating uncontrollably. Nice idea, but I doubt the algorithms are sufficient for this application. It does merit study and development however, since it would be a great idea if it could be made to work safely.
VincentWolf
Eventually all Semi truck trailer combo's will be electric as the additional power plus storage plus safety issues will surmount any other types of locomotion (e.g., diesel with stupid 8 wheel drive). computers are so fast today that the tandem electric semi and electric trailer will make jack knifing a thing of the past as they can instantly vector torque to each wheel independently and apply either power or braking to make sure the tractor trailer stays in a straight line. I completely disagree with Malatrope and I too am an engineer--mechanical engineering degree (actually 4 degrees--chemistry, ME, Wood Science & Engineering and Math).
andy42
I agree with VincentWolf, the progress of computer control since Malatrope's 1992 attempt is staggering.Who would in the 1990's have believed the science fiction that predicted today's reality? I worked with hydraulic activated robots built in the 70's with circuit board cabinets the size of wardrobes. Now a million more information is held in chips too small to see without a magnifying glass and speeds only geeks thought possible.
toyhouse
Many random thoughts here; handling issues aside, how will this trailer/vehicle be viewed by the government for purposes of taxation and registration? What exactly is it? I'm sure, politicians will figure it out, lol. Secondly, the idea of reducing towing resistance seems almost intoxicating for those who know the feeling of dragging a heavy trailer over a mountain pass, but just wondering about the capacity. Some mountain passes are really long. If the battery charge is depleted long before the uphill segment is completed, the tow vertical is now hauling a lot of additional dead-weight over the pass and having to break for it going back down. If the intent was to enable smaller tow vehicles -- that's not good at all! But it does raise the option of additional braking using a regen mode - that wasn't mentioned on this particular product unless I missed it. It also adds options maybe never before possible - anti jackknife perhaps? Anyway, using this tech to lower the tow vehicle size or rating, sounds like playing with fire. However, using it on very low settings, to reduce fuel burn in certain operating parameters, sounds interesting.
jasonhc73
I can't wait for the drive package to be made available for every other trailer. This seams like the way to make trucking go hybrid. Making a big truck hybrid just isn't catching on. Technology and sensors are finally catching up with the performance needed for this to work.
vastman
This is awesome... I'd luv one for my model 3...it IS the future and how they can make it work... Also like the idea of a pop-up style battery extender trailer... To extend range when needed for getting away from it all... And this also could bluff into the home micro grid and add to the Tesla power wall concept! Poly battery use dramatically increases the value of these products... Awesome forward thinking
aleadroid
This might work well with a hybrid power train, particularly one with “electric only” traction. (Something like the Chevy Volt) Alternatively, if it were equipped it with its own engine driven generator, one might be able to tow it using a purely electric car, with the trailer engine being used to charge both. It’s not zero emissions, of course, but would be much less intrusive than the giant pickups and such often used to tow RV trailers these days. It’s true, though, that in any case, the control system for the axles would need to be very, very carefully developed.
Bob Stuart
I have always wanted a bicycle trailer that follows without resistance. This virtual weight reduction sounds good, but what about the wind resistance and tire drag? [You might want to check out the powered Ridekick bicycle trailer, which actually pushes cyclists along: https://newatlas.com/ridekick-motorized-bicycle-trailer/20953/ - Ed.]
jerryd
For a lot less money they could have just made it lighter and aero to achieve the same goal. KISS And I hope the battery weight is concentrated close to the axle.
ProfessorWhat
This is actually brilliant but it's far from an original idea at all, this is pretty much just the reverse (inverse?) version of Slugs: https://en.m.wikipedia.org/wiki/Slug_(railroad) If they made some kind of universal hookup, then it could work the same way with a hybrid car with it effectively being the same as a diesel freight train... or in this case an Amtrak train.