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Lutz

Caravan with electrically powered axle

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At the recent Caravan Show in Düsseldorf, Dethleffs presented a study of a joint venture with ZF to demonstrate the possibility of having an electrically driven axle on a caravan. The idea behind the project is primarily to provide a future basis for electrically powered cars which would otherwise suffer serious reductions in range when towing a caravan. The principle on which it works is to constantly monitor and provide support by adjusting the towload electronically so that it never exceeds 100kg. This would enable electric vehicles to tow caravans of substantial MTPLM although they may only be approved with miserably low towing limits.

The electric motors double up as a motor mover and an ESP feature can also be incorporated in the system which would be superior to ATC and thus make ATC unnecessary.

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15 minutes ago, Lutz said:

The idea behind the project is primarily to provide a future basis for electrically powered cars which would otherwise suffer serious reductions in range when towing a caravan.

 

How will it avoid the range reduction when towing? The energy has to come from somewhere, either from the car battery pack via a heavy-duty cable or batteries added to the caravan.

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Anything to do with ZF and it won't be cheap.

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Apparently there is an integrated lithium battery (skateboard-style) in the chassis. At 80-kWh it has more capacity than the the base-level Tesla Model S. The battery sends power to the electric axle that has a 40-kW motor at each wheel. Solar panels on the caravan's roof help keep the battery charged.

See information here.

As I understand it the forward motion of the trailer would be from the trailer's battery while the "towing" vehicle would simply provide directional control.

It is an interesting concept and with battery technology improving all the time, something that may well progress beyond a concept in the near future.

See also here

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8 minutes ago, Gordon said:

Apparently there is an integrated lithium battery (skateboard-style) in the chassis. At 80-kWh it has more capacity than the the base-level Tesla Model S. The battery sends power to the electric axle that has a 40-kW motor at each wheel. Solar panels on the caravan's roof help keep the battery charged.

See information here.

As I understand it the forward motion of the trailer would be from the trailer's battery while the "towing" vehicle would simply provide directional control.

It is an interesting concept and with battery technology improving all the time, something that may well progress beyond a concept in the near future.

See also here

 

The Tesla battery weighs 4-500 kg, just the extra weight caravanners don't need!

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Solar power for the internal services of this motorhome.

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5 minutes ago, Gordon said:

 

Solar power for the internal services of this motorhome.

 

 

Yes, that was Dethleffs contribution to the Caravan Show last year. Dethleffs are always good for technical innovations.

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I suggested this ages ago, theyve nicked my idea LOL

 

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50 minutes ago, Black Grouse said:

 

The Tesla battery weighs 4-500 kg, just the extra weight caravanners don't need!

But if the caravan is self-powered, the weight becomes irrelevant from a towing perspective.

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55 minutes ago, Black Grouse said:

 

The Tesla battery weighs 4-500 kg, just the extra weight caravanners don't need!

That depends on your viewpoint! It could be argued that adding 500kg evenly  in the centre section of floor would actually yield a substantial improvement in stability which, combined with the motors, enable it to be towed by a smaller, lighter car!

Not to mention the stability improvement on steep downhill roads that could be achieved by regenerative braking of the caravan.

I wonder if we will ever see the caravan parking bays at motorway services having two fast charge points, one for the car and one for the van!

It triggers an interesting thought, what about an active stability control by actually steering the caravan wheels as well? Which could also be used when manoeuvring, such as through gateways! 

 

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18 minutes ago, Flying Grandad said:

But if the caravan is self-powered, the weight becomes irrelevant from a towing perspective.

 

Not from a stabilty perspective it doesn't!

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1 minute ago, Black Grouse said:

 

Not from a stabilty perspective it doesn't!

That depends on the assumption you make!

Many people argue that caravans behave differently to other trailers because of the high centre of gravity. Adding 500kg in the floor would substantially lower the CoG.

If they continue with this idea Dethleffs will have to do some serious testing, I hope they make the findings public!

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30 minutes ago, Flying Grandad said:

But if the caravan is self-powered, the weight becomes irrelevant from a towing perspective.

However the car is still restricted by its maximum gross train weight.

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12 minutes ago, Durbanite said:

However the car is still restricted by its maximum gross train weight.

Under current legislation, yes.

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28 minutes ago, Stevan said:

Under current legislation, yes.

 

no pun intended :D

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Now to design a "A" frame seat and a jockey steering wheel, where's me goggles :mellow:

 

Which reminds me of the first time I saw a motor-mover at Hawes, she was sat on the seat in the caravan driving it towards the car.

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Laws would need changing and unless there is a commercial version that is unlikely to happen. Do you remember the bendy bus?  This bent the law for trailers, the Steelworks in Shotton Deeside use to have trailer buses to take workers around the works, the idea was simple, the artic units on shift change were used to take workers from and to railway station, then for rest of shift same units pulled normal trailers, however these were not permitted on public roads as there is a ban from riding in or on a trailer.

 

So the bendy bus had the engine in the trailer, which pushed the front bit, so it was no longer considered as a trailer, so the same would apply to a caravan with power, it is no longer a trailer but part of the vehicle, so it would need to comply with all vehicle regulations, all windows would have to be toughened glass for example,  it would need to be MOT'ed and you would need some method of the driver applying brakes without the vehicle moving.

 

If commercially there is a need for the same technology then this may happen, the idea of a trailer with batteries which are charged while it is being unloaded with an artic unit which has small batteries to get it light from A to B but uses the trailer batteries to transport any load maybe the way forward, once this is adopted then maybe it will move across to cars and caravans.

 

However can't see anyone funding the development costs the other way around. There have been loads of good ideas which have failed because the law and government has restricted there development, the whole reason the industrial revolution was in the UK and not France was down to French government rules. The small articulated vehicle (Class 4) failed as people did not hold Class 4 licences so finding van drivers was hard.  

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Similarly in the 1960s bubble cars had to have three wheels (not four) and I believe reverse gear disabled, to be driven on a motorbike licence in the UK but the much safer four wheel versions were permitted in other countries.

Don't you just love the law makers . . . 

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Bendy buses are to be found in regular service all over the Continent. They are obviously considered as one unit because it is impossible to separate the two halves as the engine is in the back. Things would be different with powered caravans and I agree that maybe some legislation would have to be revised in order to make them legal.

Such caravans wouldn't have to be fitted with toughened glass windows as you say, though, because plastic glazing is acceptable and compliant with existing regulations, even for cars (windscreens excepted).

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As with all things new the rules may have to change. We may well lag behind the rest of europe now in approving things like this. It seems like a good idea to me if it can be seen through to a working unit. We may see them being pulled around europe long before our manufacturers catch on.

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3 hours ago, Black Grouse said:

 

Not from a stabilty perspective it doesn't!

 

On 13/09/2018 at 12:54, Lutz said:

and an ESP feature can also be incorporated in the system which would be superior to ATC

With ESP, and a (presumably) lower CofG, if correctly loaded, stability should not be a issue

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Ericmark, the reason the industrial revolution took of in the Uk was because of the raw materials, canon making, and beer making, and most importantly we as a nation were allowed to think for ourselves  and not cut off from the rest of the world as was China and Japan, if you can, read a book called "When the world took off", slight thread drift, sorry.

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I view this as more of a concept showing off innovation rather than a pre-production sample.   Sure, viewing it as a "new caravan" poses lots of thought-provoking questions and doubts, but viewing it as a pure concept could see some of the ideas developed further and maybe end up some place completely different.

 

Imagine how comical the idea of the internet or a smart phone would have appeared to the general public if discussed in the 1960's?

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On 14/09/2018 at 11:48, ericmark said:

Laws would need changing and unless there is a commercial version that is unlikely to happen. Do you remember the bendy bus?  This bent the law for trailers, the Steelworks in Shotton Deeside use to have trailer buses to take workers around the works, the idea was simple, the artic units on shift change were used to take workers from and to railway station, then for rest of shift same units pulled normal trailers, however these were not permitted on public roads as there is a ban from riding in or on a trailer.

 

So the bendy bus had the engine in the trailer, which pushed the front bit, so it was no longer considered as a trailer, so the same would apply to a caravan with power, it is no longer a trailer but part of the vehicle, so it would need to comply with all vehicle regulations, all windows would have to be toughened glass for example,  it would need to be MOT'ed and you would need some method of the driver applying brakes without the vehicle moving.

 

If commercially there is a need for the same technology then this may happen, the idea of a trailer with batteries which are charged while it is being unloaded with an artic unit which has small batteries to get it light from A to B but uses the trailer batteries to transport any load maybe the way forward, once this is adopted then maybe it will move across to cars and caravans.

 

However can't see anyone funding the development costs the other way around. There have been loads of good ideas which have failed because the law and government has restricted there development, the whole reason the industrial revolution was in the UK and not France was down to French government rules. The small articulated vehicle (Class 4) failed as people did not hold Class 4 licences so finding van drivers was hard.  

 

Passenger-carrying artic trailers were normal at airports before the modern type of terminal - but that's airside so not subject to RTA regulations.

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