Caravan with EV battery on board
Discussion
Just musing.
To offset the range reduction seen when towing, would it be beneficial to equip caravans / car trailers / tip run trailers etc. with an on board EV battery. When charged, that would provide additional electricity storage to offset the reduced range seen by the towing vehicle.
Does the weight of the battery mean that there is minimal benefit? Is the cost prohibitive for occasional use? The towed weight would increase significantly, but a heavy EV should be able to tow a heavier trailer.
Looked at from the other direction, having a battery in the caravan means that to achieve a certain towing range, the car can have a smaller battery to carry around for the rest of its journeys.
Thoughts?
To offset the range reduction seen when towing, would it be beneficial to equip caravans / car trailers / tip run trailers etc. with an on board EV battery. When charged, that would provide additional electricity storage to offset the reduced range seen by the towing vehicle.
Does the weight of the battery mean that there is minimal benefit? Is the cost prohibitive for occasional use? The towed weight would increase significantly, but a heavy EV should be able to tow a heavier trailer.
Looked at from the other direction, having a battery in the caravan means that to achieve a certain towing range, the car can have a smaller battery to carry around for the rest of its journeys.
Thoughts?
Weight isn't really a major determinant of EV range. Aerodynamics are usually much more significant. So if you're towing something that knackers your aerodynamics, then it'll knacker your range. I don't know how much drag a caravan generates, but given it's sitting in the spoiled air coming off the back of the car, I would guess it wouldn't add too much extra drag.
Could you add a big battery to a caravan? Yes and it might be rather good to be able to have a load of power available for the caravan itself. But you'd need the car's electrics to be able to accept power from this additional battery and you'd either need to be able to charge it via the car's battery management system or the caravan would have to have its own and then you'd need to plug that in to charge independently of the car. And the interoperability with the car is going to require a load of aftermarket mods in the absence of a standard way of plugging more batteries into a car. At the moment that all translates to "could be done but would cost a fortune". It would be nice if a standards arose for more modular battery designs.
Could you add a big battery to a caravan? Yes and it might be rather good to be able to have a load of power available for the caravan itself. But you'd need the car's electrics to be able to accept power from this additional battery and you'd either need to be able to charge it via the car's battery management system or the caravan would have to have its own and then you'd need to plug that in to charge independently of the car. And the interoperability with the car is going to require a load of aftermarket mods in the absence of a standard way of plugging more batteries into a car. At the moment that all translates to "could be done but would cost a fortune". It would be nice if a standards arose for more modular battery designs.
Such things do exist. Unsurprisingly they’re not cheap, but an interesting concept nonetheless. Particularly as far as eco camping goes, which is popular in the US.
https://pebblelife.com/
https://pebblelife.com/
Reading some of the EV towing threads, a battery in the towed caravan sounds sensible as adding towed weight isn't as bad as the brick aero. But is it worth it? A battery of any decent size is going to cost a certain amount because of limited market and "noobness". And then you have to figure a way of wiring it into an EV, so lets say £3-6k. That gets you a lot of charging even at high priced motorway services.
In some respects it does sound like a good idea as you could cook/heat/light/power purely from the larger caravan battery.
In some respects it does sound like a good idea as you could cook/heat/light/power purely from the larger caravan battery.
Drag is what destroys the efficiency.
I typically get 32mpg towing my 1250kg caravan with my Yeti which can usually get high 50's mpg on the same run without.
I haven't looked at the towing ability of EV's but Toyota and Lexus hybrids are rubbish, although I think that's mainly due to the strange CVT gearboxes they use.
There has been talk in the caravan club mag about the difficulties of changing and it usually means uncoupling to get access to a bay, not practical really.
Also I would imagine the connection between the two batteries would need to be quite substantial and would require some form of split charge/ discharge circuitry adding to the cost.
I typically get 32mpg towing my 1250kg caravan with my Yeti which can usually get high 50's mpg on the same run without.
I haven't looked at the towing ability of EV's but Toyota and Lexus hybrids are rubbish, although I think that's mainly due to the strange CVT gearboxes they use.
There has been talk in the caravan club mag about the difficulties of changing and it usually means uncoupling to get access to a bay, not practical really.
Also I would imagine the connection between the two batteries would need to be quite substantial and would require some form of split charge/ discharge circuitry adding to the cost.
JQ said:
POIDH said:
I'm intrigued how you would charge a caravan and car on public chargers.
With a drive-thru charger - quite common in Europe and now being rolled out in the UK. However, I've not seen any yet which I assume means the majority of the 120,000 EV chargers in the UK are 'end on' parking bays. And many in existing car parks with not as much space as I would like to tow a caravan around, reverse etc.
Unless of course you are either planning a holiday only around drive through charger locations or expecting the we are about to rebuild many of those 120,000 charging locations?
POIDH said:
JQ said:
POIDH said:
I'm intrigued how you would charge a caravan and car on public chargers.
With a drive-thru charger - quite common in Europe and now being rolled out in the UK. However, I've not seen any yet which I assume means the majority of the 120,000 EV chargers in the UK are 'end on' parking bays. And many in existing car parks with not as much space as I would like to tow a caravan around, reverse etc.
Unless of course you are either planning a holiday only around drive through charger locations or expecting the we are about to rebuild many of those 120,000 charging locations?
Europe seems a bit more advanced than the UK and I’ve used plenty of drive-thru chargers over there. But as said they are now being rolled out here so availability will improve.
To be honest it seems crazy. Caravans get used 3 months of the years, so for 9 months the battery would sit there unused. Should the battery drain below the minimum voltage its basically bricked. I would think your better sucking it up with crappy UK charging points. You can get camping batteries with solar panels if you want to saving draining your car battery when your onsite.
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