Battery powered Caravan demoed

[Tobes]

So Airstream have a proof of concept of a caravan with an 80kWh battery and motors built in to help with range when towing with an EV. Looks interesting!

Airstream reveals eStream electric caravan concept | Electrifying

Twin motor 80kWh assistance drive makes towing an Airstream less of a drag. Read more on Electrifying.com

www.electrifying.com

 

[Buckman]

So Airstream have a proof of concept of a caravan with an 80kWh battery and motors built in to help with range when towing with an EV. Looks interesting!

Airstream reveals eStream electric caravan concept | Electrifying

Twin motor 80kWh assistance drive makes towing an Airstream less of a drag. Read more on Electrifying.com

www.electrifying.com

Good for them however I doubt very much if the majority of caravanners in the UK would ever be able to afford the Airstream or even similar from a UK manufacturer. I would think that weight would be an issue even for an EV?

 

[otherclive]

Good for them however I doubt very much if the majority of caravanners would ever be able to afford one Airstream or not. I would think that weight would be an issue even for an EV?

A Rivian can handle an airstream electric or conventional, and Ford and GM vehicles will too. But they are focused on the North American market.

 

[Tobes]

Good for them however I doubt very much if the majority of caravanners in the UK would ever be able to afford the Airstream or even similar from a UK manufacturer.

I think it’s the proof of concept that is important. ALKO have shared the idea of a powered chassis before, so hopefully (if useful) it could be adopted by other manufacturers.

I would think that weight would be an issue even for an EV?

That is definitely an issue, but one that is perhaps not insoluble. It seems to me that this would become a new class of trailer with a new class of towing homolgation. Today we have two for unbraked weight and braked weight. Perhaps the answer is to have an additional for self powered trailer? It would require a number of additional capabilities to be built into the trailer, but none of which are foreign. Namely, active breaks that can stop the trailer without leveraging over-run, hitch head stabiliser and active yaw control to control snaking and reduce the chance of jackknife,
This might allow for any new car to safely tow loads much heavier than possible today. Admittedly it’s a long way off, but a possibility for keeping long range towing an option.

 

[Raywood]

Given the weight of the batteries some thought would have to be given as to what you can tow as we would need to know what weight the caravan would move and presumably deduct this from the towed weight. Life is complicated enough on weights, but this might add more problems.

 

[Tobes]

Given the weight of the batteries some thought would have to be given as to what you can tow as we would need to know what weight the caravan would move and presumably deduct this from the towed weight. Life is complicated enough on weights, but this might add more problems.

Given that the caravan would be just "assisting" the car, I am not sure that is a problem. The example showed the caravan having 240ps. That is considerably more than my XC90 had (185ps) to move the car AND the caravan combined. High power output is needed for acceleration and to overcome drag. At legal motorway speeds, 240ps is a hefty dollop of punch, especially if you tow car is an EV too, and likely to have 150ps or more on its own.

Based on todays weight model, it's not straightforward. But who says today's model will persist? EVs are throwing all sorts of previously accepted truths out of the window (like you have to fill at a fuel station, or you have to wait with your car while it's fuelled, or _perhaps_ tax will be collected on miles you drive and not on fuel you buy).

 

[Buckman]

Given that the caravan would be just "assisting" the car, I am not sure that is a problem. The example showed the caravan having 240ps. That is considerably more than my XC90 had (185ps) to move the car AND the caravan combined. High power output is needed for acceleration and to overcome drag. At legal motorway speeds, 240ps is a hefty dollop of punch, especially if you tow car is an EV too, and likely to have 150ps or more on its own.

Based on todays weight model, it's not straightforward. But who says today's model will persist? EVs are throwing all sorts of previously accepted truths out of the window (like you have to fill at a fuel station, or you have to wait with your car while it's fuelled, or _perhaps_ tax will be collected on miles you drive and not on fuel you buy).

I think the issue may arise with the EV car's maximum permitted train weight. I am not sure of the maximum towing weights of EVs in comparison to their MIRO or kerbweight, but including a driver i.e. vehicle weighs 2000kg but can only tow a maximum of 1600kg or vehicles weighs 1600kg but cna tow up to 2000kg. It could be interesting reading. I suppose with the EC being powered it will also have an effect on range of the EV towing it.

 

[Tobes]

I think the issue may arise with the EV car's maximum permitted train weight. I am not sure of the maximum towing weights of EVs in comparison to their MIRO or kerbweight, but including a driver i.e. vehicle weighs 2000kg but can only tow a maximum of 1600kg or vehicles weighs 1600kg but cna tow up to 2000kg. It could be interesting reading.

That's why I suggested a new class of homologation may be needed. To specifically allow for heavier trailers that are powered and capable of train stability management.

I suppose with the EC being powered it will also have an effect on range of the EV towing it.

Yes - that would be the major benefit. It would all but eliminate the drop in range caused by the drag of the towed trailer, and would allow an EV like mine with a solo 250 mile range at 56mph to tow for 250 miles at 56mph.

 

[RogerL]

The all-electric caravan is more likely to succeed outside Europe/UK as towing weights here are very conservative - in Australia and North America they think nothing of towing caravans and travel trailers up to double the weight of ours but using similar SUVs to us.

So an Airstream weighing 3,500 kg because of big batteries isn't going to worry them over there.

 

[Raywood]

My point would be that the car is not towing the weight of the caravan but something less. At the moment I am not sure how you would deal with this.

 

[Tobes]

My point would be that the car is not towing the weight of the caravan but something less. At the moment I am not sure how you would deal with this.

Exactly this. Of course is does beg the question, “what if the batteries are flat?” Can you only tow it legally if it’s fully charged? Lots of questions, but it presents possible future options.

 

[ProfJohnL]

The Airstream concept it is certainly an interesting suggestion and it would certainly help to address the problems of reducing EV's driving range when towing.

However as things stand in the UK (and I think the EU) at present the Airstream concept could not be used, as Tobes correctly points out there is no vehicle category for driven trailers for towing behind small vehicles.

I have previously toyed with idea of having a trailer with a large battery, and using it to supplement the Battery in an EV. But I didn't have the funds to explore it further.

The question of towed weight has been raised. and it seems unlikely that a standard UK caravan could have a substantial battery ( and motor) without it becoming impractically heavy, and beyond the the weight capacity of most cars.

But as Raywood suggests, if the caravan were self powered, and it were controlled in such a way that it accelerated and braked in unison with the tow vehicle, the actual towing loads on the hitch would be minimal, and thus the tow vehicle would not see/feel it as a heavy trailer. This could be achieved by having a smart hitch with load sensors, and electrical control signals from the tow vehicle.

Of course the other major issue will be the cost of such a caravan, and it would almost certainly need to be registered and insured like a car.

 

[Buckman]

Another question is that if the caravan is in storage for a couple of months and the batteries go flat, isn't there a possibility that with the batteries drawing power from the towing vehicle to recharge it will substantially reduce the towing range?
Also if on an electric hookup surely with batteries recharging they will draw a lot more electric to charge up therefore making the case of installing metering per pitch very valid?
On CAMC sites numerous bollards have four connections so to instal metering may require for the whole bollard to be changed. On many CLs many bollards have at least 2 connections so for owner to install metering it may be an expensive exercise and simply cheaper to shut down the CL? Also the issue of unscrupulous people swapping connections when the other user is out and about. We have had this happen to us on at least 2 occasions, once of a CL and another time on a commercial site while we were out although the pitches were not metered.

 

[Tobes]

Another question is that if the caravan is in storage for a couple of months and the batteries go flat, isn't there a possibility that with the batteries drawing power from the towing vehicle to recharge it will substantially reduce the towing range?

It has 900w of solar on the roof. That would trickle charge the batteries over a few weeks, rather than drain them.

Also if on an electric hookup surely with batteries recharging they will draw a lot more electric to charge up therefore making the case of installing metering per pitch very valid?

Definitely. But I would measure my electricity usage for the car and pay for that separately today anyway. Doing the same to trickle charge the trailer would make sense. Going by the costs on other sites 80kWh would cost between £13 and £24. Given that that amount would equate to perhaps 100 miles of towing, that seems like good value.

On CAMC sites numerous bollards have four connections so to instal metering may require for the whole bollard to be changed. On many CLs many bollards have at least 2 connections so for owner to install metering it may be an expensive exercise and simply cheaper to shut down the CL? Also the issue of unscrupulous people swapping connections when the other user is out and about. We have had this happen to us on at least 2 occasions, once of a CL and another time on a commercial site while we were out although the pitches were not metered.

A valid concern. With the adoptance of EVs as tow cars, the mechanism for charging for electricity on a pitch may well have to change anyway. Dependent on the bollard, there may be a whole bunch of ways to solve this. For example, a din rail mounted meter, https://www.cef.co.uk/catalogue/pro...U_JGpcX95hsP7B4ufowaAnisEALw_wcB&gclsrc=aw.ds

 

[Buckman]

Tobes, once again thanks for the interesting information. I would guess that with 900w solar panels plus the batteries the caravan must weight a lot more than most SUVs could tow.
However I was thinking more that if UK manufactuers adopted the idea we may have a similar scenario with UK caravans and weight.

 

[otherclive]

Tobes, once again thanks for the interesting information. I would guess that with 900w solar panels plus the batteries the caravan must weight a lot more than most SUVs could tow.
However I was thinking more that if UK manufactuers adopted the idea we may have a similar scenario with UK caravans and weight.

North American vehicles such as the F150, Rivian and Ram etc have much larger towing capability than European vehicles. Airstream have always been designed for the North American market, any official entries over here didn’t do well, but you do see a few around. Like this one parked up next to us homeward bound from Santander. Chatting with the owner the Bentley did tend to overheat on some Spanish passes but nothing that a quick stop wouldn’t fix

 

[ProfJohnL]

Another question is that if the caravan is in storage for a couple of months and the batteries go flat, isn't there a possibility that with the batteries drawing power from the towing vehicle to recharge it will substantially reduce the towing range?

Firstly if an 80kWh was drained by an alarm or similar items in just a few months, there is something seriously wrong either the appliances or the battery. Also I doubt the battery for the driven wheels in the caravan would be recharged by the car so that should not be a problem for the car.

Also if on an electric hookup surely with batteries recharging they will draw a lot more electric to charge up therefore making the case of installing metering per pitch very valid?

On CAMC sites numerous bollards have four connections so to instal metering may require for the whole bollard to be changed. On many CLs many bollards have at least 2 connections so for owner to install metering it may be an expensive exercise and simply cheaper to shut down the CL? Also the issue of unscrupulous people swapping connections when the other user is out and about. We have had this happen to us on at least 2 occasions, once of a CL and another time on a commercial site while we were out although the pitches were not metered.

I think the issue of caravan pitch outlets is likely to arise with or without the Airstream type of caravan as drivers move over to EV's. If CL's or any other site owner is concerned about the issues you have described, they are going to have to come to some sort of arrangement anyway to cater for EV's in the near future.

Perhaps site outlets will need to be locked in some way that prevents the unauthorised removal of a plug connector. It could be a mechanical interlock that cuts the power if the plug is removed, and it needs the site operator to reset it each time.

Metering is certainly possible, and yes it will involve a cost to the site owner, but that's no differnt to the cost of adding or modifying any type of service, and must be covered in their business plans. But metering isn't going to solve the theft of electricity as you describe.

Its almost certain that adapting sites for EV's or high demand caravans, is going to require some investment, adn that will lead to increased pitch fees.