MaryC
Well-known member
Does anyone know if the Leaf will be towable by an RV. Since electric cars are very RV park friendly(lots of 50amp circuits) They might be a good toad.
Flat Tow/Recreational tow
- Thread starter MaryC
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Mary, Nissan's party line on an ICE vehicle is no - they can not be flat towed. Reasoning - the transmission/drivetrain is not getting proper lubrication. Since the LEAF has no conventional transmission, it remains to be seen if they will approve flat towing.
garygid
Well-known member
You can tow it on a suitable trailer, but remember that the LEAF is a bit heavy.
Towing on 4 wheels (or with a front-wheel dolly) is probably not possible because of the (likely) automatic, 4-wheel Parking Brake system.
Can that system be disabled?
Probably only by turning the LEAF fully ON.
But, there could be a "parking-release" to override the system.
Then, towing on a front-wheel dolly is likely to be possible, since the rear wheels "should" turn freely.
The "flat" towing in the post above referred to 4-wheels on-the-ground towing.
Towing on 4 wheels (or with a front-wheel dolly) is probably not possible because of the (likely) automatic, 4-wheel Parking Brake system.
Can that system be disabled?
Probably only by turning the LEAF fully ON.
But, there could be a "parking-release" to override the system.
Then, towing on a front-wheel dolly is likely to be possible, since the rear wheels "should" turn freely.
The "flat" towing in the post above referred to 4-wheels on-the-ground towing.
KeiJidosha
Well-known member
As a toad, it weighs more than a Jeep Wrangler. In addition to the “Parking Brake” issue, there is no “clutch” between the differential and the rotor. That would mean the motor spins with the front tires. Since this is a magnetic armature, you will get inductive drag (and voltage generation in the stator windings). This could be a problem producing not just drag, but back voltage in the inverter, which it’s not able to deal with power off.
TimeHorse
Well-known member
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- May 13, 2010
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Well, as we said in the other thread, turn the car on and leave it in ECO mode. First talk to a dealer if this is safe, but logically if they've designed the regenerative breaking such that it simply uses front tire motion to provide angular velocity and torque to the electric motor turning it into a generator which in turn charges the battery and where as in normal Regenerative Breaking, this is only activated by the break, the ECO mode, AFAICT, is activated by the lack of any pressure on the accelerator. Of course, this is all in theory.
planet4ever
Well-known member
Hey, we were joking in that "other thread". Surely no one would seriously consider dragging a Leaf behind an RV while it was turned on and in Eco mode. Why would you want to push your already terrible RV mileage/gallon down even further just so you can do some inefficient charging from diesel or gas while you are driving? What you want in an RV toad is something you can pull with little resistance and charge by plugging in at the campground.
Well, OK, what you really want is little resistance and low inertia. The Leaf's weight means it fails on inertia, and it may fail on resistance unless the front wheels are off the ground. On the other side of the equation, what you usually need is a runabout for short excursions, rarely more than twenty or thirty miles at a pop, in my experience. The Leaf range is overkill.
P.S. I'm speaking from historical experience only. We gave up our RV lifestyle about five years ago due to ecological concerns.
Well, OK, what you really want is little resistance and low inertia. The Leaf's weight means it fails on inertia, and it may fail on resistance unless the front wheels are off the ground. On the other side of the equation, what you usually need is a runabout for short excursions, rarely more than twenty or thirty miles at a pop, in my experience. The Leaf range is overkill.
P.S. I'm speaking from historical experience only. We gave up our RV lifestyle about five years ago due to ecological concerns.
actually I was wondering JUST that. can you flat tow the leaf and regen charge it long term. ie for say 30 minutes.
might be a cheap way to "boost" a dead battery to a usable power level (couple bucks in gas)
also might be nice if we had a brake controller for rv towing so when on level of climbing me eliminate regen but when going downhill but butt tons of inertia we can enable mild regen to not only slow the rv a little bit but recharge the car at the same time. Free power basically.
would be interesting if that could be made to work.
might be a cheap way to "boost" a dead battery to a usable power level (couple bucks in gas)
also might be nice if we had a brake controller for rv towing so when on level of climbing me eliminate regen but when going downhill but butt tons of inertia we can enable mild regen to not only slow the rv a little bit but recharge the car at the same time. Free power basically.
would be interesting if that could be made to work.
cwerdna
Well-known member
http://green.autoblog.com/2011/05/25/is-the-quickest-way-to-charge-a-nissan-leaf-by-towing/" onclick="window.open(this.href);return false;nerys said:
wow. seems like it worked PERFECTLY. they thought the computer flipped out (no it did not it just correctly reported the range he would get he if coasted with regen that much of course it recalculated once he started USING the battery and it got good data)
Very very cool. maybe not good for long term charging of course but in a pinch I think it would make for impressive results. it can charge at some 30+ kw in regen after all.
I wonder if anything gets hot doing this? the motor can sustain 30kw with no problem so I don't think it would over heat.
the battery can take a 30 minute DCQC charge so it should be ok with a short 10 minute tow charge too.
Very very cool. maybe not good for long term charging of course but in a pinch I think it would make for impressive results. it can charge at some 30+ kw in regen after all.
I wonder if anything gets hot doing this? the motor can sustain 30kw with no problem so I don't think it would over heat.
the battery can take a 30 minute DCQC charge so it should be ok with a short 10 minute tow charge too.
essaunders
Well-known member
Wufnu said:
How is it a waste of gas? Assuming you'll tow some vehicle, it might be a wash. Once the LEAF is fully charged it'll stop trying to regen. the only 'waste' I'd see is the LEAF baseline load (couple of hundred watts).
Off course, i can't possibly see Nissan saying this is OK...
TomT
Well-known member
Yes, it does, just as it registers them coasting down a hill in neutral...
nerys said:
Because charging your vehicle by towing it is a big waste of energy due to regeneration inefficiency and inefficiency in towing. Better off to use a generator. I would only tow-charge if I absolutely had to. It's not free energy; it's like towing a car with the brakes lightly on. Fuel isn't cheap. If it's an emergency one time deal, no problem, but towing it behind and RV? No bueno.
Yes it's really in neutral and yes it's really adding miles to your odometer. The added miles will cause it to depreciate like a brick. If you're going to own it forever, who cares, no big deal. Most people won't. It doesn't have a real neutral so the motor will be spinning. This causes more problems in towing.
Tow dollies are cheap and easy to use. Buy used. Get a tow dolly to drag your Leaf behind your RV and enjoy all the benefits with none of the downsides. If someone can afford a $50,000 - $100,000 RV, the fuel it guzzles, and is looking to tow a $30,000 car then I think the least they can do is spring a few hundred bucks to protect both of their expensive properties.
Yes it's really in neutral and yes it's really adding miles to your odometer. The added miles will cause it to depreciate like a brick. If you're going to own it forever, who cares, no big deal. Most people won't. It doesn't have a real neutral so the motor will be spinning. This causes more problems in towing.
Tow dollies are cheap and easy to use. Buy used. Get a tow dolly to drag your Leaf behind your RV and enjoy all the benefits with none of the downsides. If someone can afford a $50,000 - $100,000 RV, the fuel it guzzles, and is looking to tow a $30,000 car then I think the least they can do is spring a few hundred bucks to protect both of their expensive properties.
Well my rv is a little 4cyl jobby 
and cost me $900.
It is free energy. Well recovery of otherwise wasted energy. When you go downhill in an rv there is no "coasting" your mass will quickly put you over the psl
So you "will" have to apply the brakes which is quite literally burning up energy as pure heat and w&t on the brakes.
Txing some of that into regen captures some of thst energy and puts it to use instead of throwing it away into the brake pads.
All I was trying to point out. Nothing more. My gassers do not add miles when I put them in neutral because the transmission is not engaged and the transmission has to spin in order to spin the speedo gear. Then again my gassers are dirt cheap simply old sticks (geo metro geo tracker) flat towing is common because it is easy fast low maintenance and less complicated. By a lot. Drive up behind the rv attach power and tow bar and drive away. Try that with a tow dolly.
Also an emergency tow charge would be about trading money (gas) for time. 30kw will recharge the battery pretty damned fast
I also have a feeling its not nearly as inefficient as you might think. Regen is 30% right? That is a hell of a lot more efficie t than your ice is.
and cost me $900.It is free energy. Well recovery of otherwise wasted energy. When you go downhill in an rv there is no "coasting" your mass will quickly put you over the psl
So you "will" have to apply the brakes which is quite literally burning up energy as pure heat and w&t on the brakes.
Txing some of that into regen captures some of thst energy and puts it to use instead of throwing it away into the brake pads.
All I was trying to point out. Nothing more. My gassers do not add miles when I put them in neutral because the transmission is not engaged and the transmission has to spin in order to spin the speedo gear. Then again my gassers are dirt cheap simply old sticks (geo metro geo tracker) flat towing is common because it is easy fast low maintenance and less complicated. By a lot. Drive up behind the rv attach power and tow bar and drive away. Try that with a tow dolly.
Also an emergency tow charge would be about trading money (gas) for time. 30kw will recharge the battery pretty damned fast
I also have a feeling its not nearly as inefficient as you might think. Regen is 30% right? That is a hell of a lot more efficie t than your ice is.
If you only travel downhill, sure it's free.
I regenerative braking efficiency is more than 30%, not sure how much, but that's efficiency of converting work your RV engine produced to begin with. So, for example, if your RV had to produce an extra 10kW to account for the extra force applied by regenerative braking on a flat towed Leaf, your leaf would only get 3kW (or whatever it would be based on real efficiency). When you have to use an ICE to pull it, no it's not more efficient than an ICE. The efficiencies multiply: %ICE*%RB*%EV = a lot less.
Yah, flat towing makes a lot of sense on a typical manual car. Unfortunately (or fortunately, depending on how you look at it), the Leaf is not typical and it doesn't have a manual transmission. Because of the differences, there are a lot of unknowns. For example, the regenerative braking feature is meant to be used intermittently or for relatively short periods of time. It may or may not be capable of running constantly for an hour. Same goes for back EMF. Components are easy to understand but the way components interact not so much. Really, the only way to know is to try. Nissan isn't going to give instructions on it and it would probably be very difficult to get all of the details from them.
I say go for it! Tell us what happens. I'm very open when it comes to experimenting with other people's property :lol:
I regenerative braking efficiency is more than 30%, not sure how much, but that's efficiency of converting work your RV engine produced to begin with. So, for example, if your RV had to produce an extra 10kW to account for the extra force applied by regenerative braking on a flat towed Leaf, your leaf would only get 3kW (or whatever it would be based on real efficiency). When you have to use an ICE to pull it, no it's not more efficient than an ICE. The efficiencies multiply: %ICE*%RB*%EV = a lot less.
Yah, flat towing makes a lot of sense on a typical manual car. Unfortunately (or fortunately, depending on how you look at it), the Leaf is not typical and it doesn't have a manual transmission. Because of the differences, there are a lot of unknowns. For example, the regenerative braking feature is meant to be used intermittently or for relatively short periods of time. It may or may not be capable of running constantly for an hour. Same goes for back EMF. Components are easy to understand but the way components interact not so much. Really, the only way to know is to try. Nissan isn't going to give instructions on it and it would probably be very difficult to get all of the details from them.
I say go for it! Tell us what happens. I'm very open when it comes to experimenting with other people's property :lol:
I think you missed my original idea. Some sort of remote switch to only turn it on "while" going down hill only. Ie regen for a couple minutes now and then when going downhill.
Tow regen on flat ground makes no sense except in desperate times.
Alas if the leaf does not truly go into neutral ie transmission still spinning is not really neutral as I am using the word. Then its probably not wise to flat tow it at all.
Tow regen on flat ground makes no sense except in desperate times.
Alas if the leaf does not truly go into neutral ie transmission still spinning is not really neutral as I am using the word. Then its probably not wise to flat tow it at all.
garsh
Well-known member
That would be a great setup. It could be simple like the trailer brakes on a boat trailer - when there's pressure on the back side of the ball joint, you activate the braking.nerys said:
The Leaf doesn't technically have a transmission at all - just some reduction gearing. There's no clutch, so if the wheels are moving, then the motor is moving with it. As has been said, the downside is that your odometer keeps spinning, and you'll end up with a "high-mileage" vehicle. But otherwise, I don't see the spinning motor as being a problem. It's not likely to develop a problem like a spinning gasoline engine or transmission would.
