RV trailer with 80kWh battery and motors

[ecarfan]

Couldn't you already make it between Superchargers pulling an unpowered trailer this size in most cases? The fact that you often have to do it at 55 mph is an issue for some people, though. Perhaps what the powered trailer does is just allow enough range boost between SCs to allow slightly faster speeds, yet still make the gap. Use 20-25% of the trailer battery between Supercharger stops just to boost speed consistently up to 65 or so. That would be on flat segments -- you'd want to have the power to use on hills, which would be this thing's forte, I would think.

The currently available Supercharger network is sometimes sufficient for point-to-point travel when towing at 55mph (the legal limit in California when towing) but sometimes not, even under optimal conditions. Suboptimal conditions; headwinds, rain, etc., greatly reduce range even when towing at 55mph. More importantly, I want to go places with my trailer where there are no Superchargers and no electricity available for any charging at all. Even relatively Supercharger-dense California is full of such places.

When not towing, my X 100D can go just about anywhere I want to go, including the mountains and deserts of California and beyond. If this Dethleffs Coco trailer battery could provide most or all of the kWh necessary to propel the trailer such that the car would use energy at the about the same level it does when not towing, that would be wonderful.

 

[ecarfan]

I suspect the target audience here is not 100D Model X owners.

Some of the articles about this trailer imply that Dethleffs had EV owners in mind when designing the trailer, but certainly they are also thinking of people with smaller, less powerful cars who would like to tow a trailer and don’t want to buy a new vehicle.

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

Of course ICE vehicles also incur a large increase in energy usage when towing, but they can generally refuel more readily than an EV can.

 

[BerTX]

Some of the articles about this trailer imply that Dethleffs had EV owners in mind when designing the trailer, but certainly they are also thinking of people with smaller, less powerful cars who would like to tow a trailer and don’t want to buy a new vehicle.

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

Of course ICE vehicles also incur a large increase in energy usage when towing, but they can generally refuel more readily than an EV can.

I don't think the goal of getting smaller cars tow larger trailers is valid. First, the legal aspect -- the weight of the trailer is what it is, whether powered or not. If you knowingly exceed the towing capacity of the vehicle and have an accident, you are likely in big trouble. Also, when the trailer is out of juice, you would have to leave it where it dies. And what about tongue weight? Smaller cars don't just have less towing capacity, but a lower tongue weight capacity. I'm not sure how all the guidelines for weight of trailer and tongue weight ratio are affected.

 

[mspohr]

and then there's these guys who need to downsize their bolt on tractor trailer system to an axle replacement system for travel trailers.

Hyliion: Class 8 Tractor Trailer Electrification.

This looks like adding a hybrid drive train to the tractor. I guess this could be adapted to a trailer.

 

[ohmman]

I don't think the goal of getting smaller cars tow larger trailers is valid. First, the legal aspect -- the weight of the trailer is what it is, whether powered or not. If you knowingly exceed the towing capacity of the vehicle and have an accident, you are likely in big trouble. Also, when the trailer is out of juice, you would have to leave it where it dies. And what about tongue weight? Smaller cars don't just have less towing capacity, but a lower tongue weight capacity. I'm not sure how all the guidelines for weight of trailer and tongue weight ratio are affected.

These are good points. With an undersized vehicle, it could introduce a new flavor of range anxiety.

All that said, Can-Am RV is known for modifying sedans to pull Airstreams, among other trailers. They have a long history of doing so, and if they can get a traditional sedan to pull those, I'm guessing it's possible to safely tow this trailer when properly set up. But it won't be plug and play.

 

[NoBeard]

This looks like adding a hybrid drive train to the tractor. I guess this could be adapted to a trailer.

They make both a tractor solution and a trailer solution.
This is what I was specifically referring to...
Trailer Solution | Hyliion

 

[ecarfan]

I don't think the goal of getting smaller cars tow larger trailers is valid. First, the legal aspect -- the weight of the trailer is what it is, whether powered or not. If you knowingly exceed the towing capacity of the vehicle and have an accident, you are likely in big trouble. Also, when the trailer is out of juice, you would have to leave it where it dies. And what about tongue weight? Smaller cars don't just have less towing capacity, but a lower tongue weight capacity. I'm not sure how all the guidelines for weight of trailer and tongue weight ratio are affected.

Safari Condo in Quebec specifically targeted their Alto series lightweight (1600 - 1700 lbs, so modest tongue weights) trailers at people with smaller vehicles. Many Alto owners tow with Subaru Foresters, Honda Ridgelines, even mini vans; cars that do not have powerful high torque engines.

The Dethleffs Coco trailer is a similar size to an Alto. And the e.Coco with an integrated battery would put even less stress on the tow vehicle powertrain.

 

[BerTX]

Safari Condo in Quebec specifically targeted their Alto series lightweight (1600 - 1700 lbs, so modest tongue weights) trailers at people with smaller vehicles. Many Alto owners tow with Subaru Foresters, Honda Ridgelines, even mini vans; cars that do not have powerful high torque engines.

The Dethleffs Coco trailer is a similar size to an Alto. And the e.Coco with an integrated battery would put even less stress on the tow vehicle powertrain.

I don't deny that it could work, only that if a car with a 2000 pound towing weight limit is pulling a 3000 pound trailer and is involved in a collision the other guy's lawyer will have a field day. And if there is an injury or death...

 

[ecarfan]

I don't deny that it could work, only that if a car with a 2000 pound towing weight limit is pulling a 3000 pound trailer and is involved in a collision the other guy's lawyer will have a field day. And if there is an injury or death...

But the Dethleffs Coco trailer is far less than 3000 lbs. As I noted in my post that you replied to.

 

[BerTX]

But the Dethleffs Coco trailer is far less than 3000 lbs. As I noted in my post that you replied to.

The electric version of the Coco will not be much less than 3000 pounds, and the Subaru Forester has a towing capacity of 1500 pounds.

 

[mspohr]

The electric version of the Coco will not be much less than 3000 pounds, and the Subaru Forester has a towing capacity of 1500 pounds.

But it behaves like a 100 kg trailer.

 

[ohmman]

But it behaves like a 100 kg trailer.

I think the idea is that of the batteries are dead, it doesn’t. So even if you can tow with a Forester, it may introduce some legal issues especially if the batteries are dead.

None of that should matter with an X, though.

 

[HyperionMark]

The electric version of the Coco will not be much less than 3000 pounds, and the Subaru Forester has a towing capacity of 1500 pounds.

Keep in mind that towing capacities in the US are rather arbitrary and artificially low due to high rates of litigation in this country. The exact same vehicles will often be given a higher capacity in other countries. Does the safety risk go up with every higher pound towed? Yes, but does that mean we should keep them off the road? By that methodology we should be keeping every semi-truck off the road due to its ridiculous long stopping time. I concede, however, that this logical thinking won't stop litigation. So....tow at your own risk?

 

[ecarfan]

The electric version of the Coco will not be much less than 3000 pounds, and the Subaru Forester has a towing capacity of 1500 pounds.

Yes, 1500 lbs towing capacity for a “dumb” trailer. According to Dethleffs the Coco trailer has a “ZEM module” that allows the owner to adjust the “defined towing weight” on the hitch such that, for example, the force on the car can be 100kg. The trailer motors provide enough propulsive force to greatly reduce the force perceived by the hitch (hence the need for a large battery in the trailer). From the point of view of the car it’s towing a very small lightweight trailer. Almost any car could tow it.

It’s a radical concept in trailer towing. Now Dethleffs has to demonstrate that they can actually do that.

 

[BerTX]

Yes, 1500 lbs towing capacity for a “dumb” trailer. According to Dethleffs the Coco trailer has a “ZEM module” that allows the owner to adjust the “defined towing weight” on the hitch such that, for example, the force on the car can be 100kg. The trailer motors provide enough propulsive force to greatly reduce the force perceived by the hitch (hence the need for a large battery in the trailer). From the point of view of the car it’s towing a very small lightweight trailer. Almost any car could tow it.

It’s a radical concept in trailer towing. Now Dethleffs has to demonstrate that they can actually do that.

As I said before, I'm not questioning whether this system will work. All I'm saying is a trailer weighing more than the towing capacity of the tow vehicle is a liability issue. The technology is irrelevant. You keep trying to force logic into a legal issue, which is a mistake.

 

[HyperionMark]

As I said before, I'm not questioning whether this system will work. All I'm saying is a trailer weighing more than the towing capacity of the tow vehicle is a liability issue. The technology is irrelevant. You keep trying to force logic into a legal issue, which is a mistake.

Haha, so true, love that last sentence.

 

[ecarfan]

As I said before, I'm not questioning whether this system will work. All I'm saying is a trailer weighing more than the towing capacity of the tow vehicle is a liability issue. The technology is irrelevant. You keep trying to force logic into a legal issue, which is a mistake.

Good point!

 

[ecarfan]

The Dethleffs electrically powered trailer is getting closer to reality, see Towing with an EV: Are electric trailers the future?

They have changed the name and appear to be actively working to bring it to market, starting in Germany.

Quotes from article:
———————————
The E.Home Caravan prototype has two battery modules, each with about 40 kwh, with one in front of the axle and the other behind it. The trailer can also provide power out for other camping needs, or support solar cells on the roof. It can be charged at up to 7.2 kw on AC, and it’s compatible with 50-kw DC fast-charging..

The drive unit for the trailer, developed by ZF, has two offset electric motors making 30 kw of continuous power (40 hp) each, or a max of 90 kw (121 hp) each. Each motor also makes a maximum 66 lb-ft of torque, but with the 16:1 reduction ratio it amounts to 1,062 lb-ft at the wheels. When the vehicle is slowing, the motors provide gentle regenerative braking and feed energy back into the battery pack. Disc brakes are hydraulically actuated and blended.

The most complex piece of kit in the setup might well be the active towing load feature for the Trailer Mobility Control unit, which adds only enough thrust from the trailer to maintain a constant towing load on the tow bar. It’s designed to be towed with a relatively low amount of power from the tow vehicle—adding more regen down hills to maintain that—and it detects and compensates for crosswinds or corners.
——————————-

I like the concept. It’s about the same size as my Alto F1743, though the most recent information I have is that unfortunately it does not offer an inside shower, just a toilet and sink with an outside shower hose.

Edit; just found the page on the Dethleffs website about their demonstration tow with the Audi e-tron, see E.HOME Alps Challenge