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I am hoping to find a reasonably priced 2016 or later Nissan Leaf SV for salvage with a smashed up body but working guts. (Suggestions beyond Copart for where to look for this?) The Nissan leaf has a motor rated at 107 hp -- the LeSharo has a 100 hp Renault engine. The Nissan Leaf has a GVWR of 4,431 lbs -- the LeSharo has a GVWR of 5,830 lbs (as close as I can tell, though this may not be exact for my model.) The 2016 Leaf SV has a range of 100 mi. I am hoping to achieve a range of 50-70 miles with a top speed of 50 mph.
If you're satisfied with the performance of the LeSharo, I expect that the Leaf powertrain would work for you.

The difference in Gross Vehicle Weight Rating (GVWR) isn't an issue, because GVWR is mostly about structure and suspension, and you wouldn't be using either of those from the Leaf.

A bigger issue would be the Gross Combination Weight Rating (GCWR), and the total loaded weight of the motorhome plus anything it is towing. This indicates how much load the powertrain can haul around. The Leaf's GCWR may not be much higher than its GVWR, and may be overloaded under the sustained heavy load of moving the motorhome.

Between size and shape the LeSharo probably has enough drag to make more of an energy consumption (and thus range) difference than that... but we're all just taking educated guesses.
 

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I am hoping to find a reasonably priced 2016 or later Nissan Leaf SV for salvage with a smashed up body but working guts.
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Does this seem like a good fit for this conversion? Does anyone have any potentially better or entirely different suggestions to consider for how to proceed?

Some questions I am wondering are. . .

Is there a way I can bypass the 3-speed automatic transmission and hook the electric motor straight up to the drive-train? Or would this be ill-advised? Mainly I would like to remove as many clunky and unreliable parts as possible. . .
The LeSharo has a first-generation Renault Trafic powertrain, which is front-wheel-drive, with the engine longitudinally oriented and placed ahead of the front axle line. The Nissan Leaf is an electric version of their common compact cars, and follows the pattern of the engine installation, with a transverse motor placement just ahead of the axle line.

I wouldn't even consider using the Renault transmission. An automatic seems like more trouble to deal with than it is worth. It might be possible to swap in a manual Renault transmission, but it's not like there are a lot Renault anything in North America, especially with that longitudinal layout with the engine overhanging the front. Audi used the same format for many years (and some VW versions of the same cars), so there might be a possibility there. You could even use the transaxle of an air-cooled VW, as long as you use a strong version, and one that can flip to the engine/motor ahead of the axle.

Since both the Trafic/LeSharo and the Leaf are front wheel drive, that suggests the possibility of using the complete Leaf drive unit (inverter, motor, and reduction gearbox with final drive) to replace both the Renault engine and the Renault transaxle. Unfortunately, the Renault is longitudinal (a configuration which was popular for early front-wheel-drive cars, especially from Europe), and the Leaf is transverse (like the vast majority of modern front-wheel-drive cars), so the Leaf unit might not fit well in the engine compartment, and certainly some significant construction of mounting brackets would be required. It can be done, and would be easier than the conversion to a transverse Pontiac engine that I ran across.

Whatever gearing bits are used, the Leaf motor will need a reduction ratio of at least 7:1 from motor speed to axle speed to work properly.
 

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Am I going to run into any brake master cylinder issues, or any other systems that might be tied into the petrol motor?
The LeSharo's brake booster will presumably need vacuum, although there was a diesel version which would have had some other boost source. You can add a vacuum pump, but another solution is to replace the entire brake master cylinder and booster with the equivalent from the Leaf, which is electrically powered.

The air conditioner (if you have one) will be run by the engine. If the RV part has a 120 V AC powered air conditioner, it might make more sense to use an inverter to run that rather than to make the Renault air conditioning work on electricity.
 

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I also intend to put solar panels on the roof of this vehicle. It just seems reasonable to me that there should be solar panels on an electric vehicle with such a large roof. I intend to include a simple and lightweight system for being able to tilt the panels when parked to better catch what sun is available.
Solar panels are good for any RV that camps without a powered campsite. Tilting panels does help, if you can position the motorhome to be able to use the tilt (most only tilt side-to-side, not front-to-back).

The solar system will extend how long you can camp without needing to move or to run a generator. It won't collect enough to make a meaningful difference to driving the vehicle.
 

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I'll have to explore and decide if I want to stick with the LeSharo brake system of switch out to the Leaf. If I use the Leaf system. . . would I have to do this for both front and backs? Seems like it might be more simple to keep the existing brakes and add the vacuum pump. . . ?
I think the Leaf parts are only a solution for the master cylinder, not for the disks, calipers, & pads (front) and drums, wheel cylinder, & shoes (rear).

Adding a vacuum pump probably is simpler. I don't know how much noise it would make or how much power it would use.
 

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... I was having some trouble finding the GCWR for both the Leaf and the LeSharo. I couldn't even find the curb weight for the LeSharo. I'm noticing that while the GVWR of the Leaf is 4,430 lbs, the curb wight is only 3,340 lbs, which is not terribly encouraging.
GCWR is often hard to find for vehicles which are not expected to tow very much, and especially for those for which towing is not recommended at all.

But I did find this article:
http://www.mynissanleaf.com/viewtopic.php?t=19293
Which leads me to believe that the Leaf should be quite comfortable towing up to 2,500 lbs beyond it's own weight.
It's good that the performance was acceptable, and the stability and structural questions won't matter to the LeSharo, but I would be a little cautious about the long-term reliability under substantial load. Presumably the motor and electronics would be protected by power reduction triggered by excessively high temperature, but the battery doesn't have active thermal management.

I'm hoping that after stripping down the LeSharo as much as I can, it wouldn't be too bad for the Leaf drive train.
All the stuff in an RV costs the manufacturer something to put there, so there usually isn't much of anything extra. Rather than just removing anything, there are sometimes lighter (and more expensive, which is why the RV manufacturer didn't use them) alternatives. Go for lighter weight, but keep your expectations low.
 

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Lots of good suggestions here for how to proceed with the gear-box, and I also appreciate the tip about the 7:1 ratio for the leaf motor. A lot of these sound viable, but I agree with you using the whole drive-train from the leaf sounds like the most attractive option. I would be slightly more concerned with the constant overweighting of the gear-box than the electric motor. . . but with the trend towards over-engineering these days. . . I think it might be OK?
It is reasonable to be concerned about the gearbox being used in a heavier vehicle than what it was designed for. On the other hand, those Leaf gears look substantial.
 

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This transverse vs longitudinal issue is one I had not considered! I'm having trouble finding information on the internet about specs/dimensions on the EM61 motor in the Leaf, which makes it hard to determine if it will fit in it's original orientation.
You might want to check out CanadaLT28's VW LT doka with Nissan leaf, and perhaps to ask him about the Leaf drive unit dimensions... which he is using intact.
 

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This video was one of the main inspirations for me on this project:

https://www.youtube.com/watch?v=fGZ1zbqAGA0


He says he's getting about a 50 mile range just off of a full-day charge on the solar panels on his VW bus.
Without really watching the video (although I did later fast-forward through it), if 50 miles requires 15 kWh of energy stored in the battery, that suggests a 2000 watt (peak) solar array, and full sun exposure. That's 20 square metres (or square yards) or so of panels, or at least far more than what fits on a VW van. So, what were his power and energy numbers?

In the video he describes how he's loosing probably 10% of this solar energy to heat build-up in his voltage boosters. . . He's only having to boost up to 144V, and I'd have to boost all the way up to 360V. . . so I will need to research more.

Do you think it might make sense for me, maybe even be more cost effective, to find a lower voltage motor, and build batteries from scratch?
It seems unlikely to me that there would be a great benefit to a lower system voltage, just due to more efficient voltage conversion, but this is not my area of expertise.

There are certainly lower voltage motors, but you can still use Leaf (or Chev Volt, or whatever) modules for the lower voltage - just use fewer modules in series.
 

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I'm a little confused about working with these 24v Tesla modules. . .
They're not really 24 volt. People seem to want battery systems to run at some multiple of 12 volts, but it doesn't work that way. Tesla Model S/X modules have 6 cell groups in series... which is 22.5 volts for the module at 3.75 V/cell (nominal).

I would need 15 or 16 of them in series to get to the 380 volts that the Leaf operates at. . . crazy expensive!
Lower-capacity Tesla Model S/X batteries had 14 modules in series; larger (100 kWh and I think 85 kWh) batteries have 16 modules in series. Yes, since (like all modern EVs) all modules are connected to each other in series, large battery capacity means that you can't use the stock modules to build a low-capacity high-voltage battery. As Kevin mentioned, some companies do modify the Model S/X modules to 12s, cutting the number of modules for a given voltage in half.
 

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. . . if I reduced the 1:7 gear ratio standard on the Leaf even further, thus lowering the top-speed, might this potentially be a better fit for a heavier vehicle like this?
Yes. :)

I'm even considering putting two Leaf gear-boxes in series, thus rendering the top speed of the vehicle to 45 mph. . . but would this also help to relieve some strain from each gear-box, and possibly also reduce the torque required by the motor? Or reduce the wear and tear on the motor? We're not trying to get anywhere fast ;)
Aside from the gearing math (which you have since figured out), it doesn't relieve the strain on the final gearing. Think of the gears in a train like links in a chain - each of them transmits the same power (everything coming out of the motor), although they are running at different speeds and therefore different torques (or loads on each tooth). If the additional reduction is after the stock Leaf gearing then the Leaf gearing would transmitting lower load at higher speed, which would be easier on the gearing.

A challenge is that there isn't any easy way to insert another stage of gearing between the existing gears and the differential. That leaves adding a gearbox on each output from the differential, either at each side of the transaxle (which would be a lot of work), or as geared hubs.

... I now understand the concept you are describing~ if I wanted to go from a 1:7 ratio to a 1:14, I would only need to add a 1:2 ratio gear. So . . . is the rest of my theory sound? If I have a heavier vehicle, and I don't mind if the top speed is slower, would it make less strain on the motor to gear it down a little further?
It would shift the motor speed and load conditions. The motor is most efficient at mid-range speed and relatively heavy load. If the change in gearing moves it from lower speeds up to a better point, and avoids maximum load (and thus maximum current for the speed), it should improve efficiency and reduce motor temperature.

It will also multiply the available torque at the wheels, by whatever reduction gearing ratio you add.
 

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Where are you finding a whole 380V 24kWh pack for $1000??? Pricing it out on eBay, I usually see a single cell (7.6V, 64AH) for about $100, which comes out to your $10k for 2 complete Leaf batteries for my project.
That's a module, containing a 2s2p combination of four cells (each cell 32 Ah @ 3.8 V), not just a single cell. There are 48 modules in a Leaf pack, so yes, two packs or 96 modules would be about $10K at $100 per module.

If the individual module price is high this may reflect the labour of disassembly and/or selection of only good modules.
 

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Err, I don't know why I said series.

What I meant was, head-to-tail. So they're both turning the same shaft.
That's in series, mechanically. :) If you want an electrical analogy, the torque of the motors add (like voltages of cells in series) and the rotational speed is the same (like the current through cells in series).

The electrical power supply to the motors would presumably be in parallel.

You could describe the mechanical configuration as "in tandem" if you want.
 

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This brings up another point I've been wondering about. The Leaf Motor (EM61) operates at 380V. What happens if I power this motor with a lower voltage battery? Say I used 12s Tesla packs and ended up with about 270 Volts? What if I got really crazy and went to 150V?

The Motor would have less power?
The Motor would get hotter?
The stock wiring would not be capable of handling the current?
The available battery voltage limits the voltage which can be supplied to the motor. At low speed the motor is current-limited, so up to some point the lower battery voltage is not a limitation. As speed rises more voltage is needed to push the current, and most production EV motors are limited to a constant power (so as voltage rises with speed, current drops in inverse proportion to the voltage), until the limit of available voltage is reached. Reducing the available voltage should just cut off the top speed end of the operating curve.

So yes, the peak power available would be less, but when operating within the available voltage and power and stock gearing there should be no change in efficiency (or heat generation, or current). You can't trade off between current and voltage by just using a lower-voltage battery.

If you change gearing to operate at a different motor speed for a given road speed, you shift to a different point in the operating curve, which may be more or less efficient. Certainly if you use taller (less reduction) gearing so the motor runs more slowly it will need to be producing more torque (for a given road speed and power output), and so will be using more current (at a lower voltage). That only means hotter if it doesn't cool as well at lower rotational speed or is less efficient at the new operating point.

This makes me wonder more crazy things. What if I used a lower power EV motor, (or wired the EM61 at a lower voltage?) and included a voltage ramper to give shorter bursts of higher power. I know there are a lot of circuits/products available out there to change voltage up or down pretty easily. I know these components get hot. Would it be possible to use one of these to provide a temporary "boost" by ramping up battery voltage for a short time?
While not a common technique, Toyota has used a voltage doubler incorporated into the inverter of some of their hybrids to run the motor at up to twice the battery voltage.
 

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Drive configurations

I got all excited imagining a set-up with 4 small DC motors, one on each wheel . . . . then I realized it would be a steering and suspension nightmare :D.
Agreed - for road vehicles, hub-mounted motors are undesirable.

Might it be remotely sane to consider having two forklift motors as you have mentioned, one in place of the old petrol motor, driving the front wheels, and the second driving the back axle. Imagining differential issues in the rear wheels might prevent this from being practical for most road driving? Maybe one motor in the front and two in the back, one for each wheel?
A differential - or separate motors per wheel - is required for any axle unless it is always on a loose surface, so front and rear are the same in this respect. At the front the LeSharo's Renault chassis comes with a transaxle containing a differential; you would need to provide a differential at the rear if using a single motor for the rear axle.

The LeSharo was designed for a front-wheel-drive chassis. Is the room to change out the rear suspension and fit in a motor (or motors) and a driven axle?
 

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Regenerative braking

I'm sure this is a common question but. . . is it easy enough to implement regenerative breaking with a forklift motor?
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Does it just depend on how I configure my speed controller, as Mr. Damien Maguire would have me build from near scratch? :p
No. "Forklift" motors have the field winding in series with the rotor winding, so the current is the same through both windings. For rational regenerative braking in a brushed DC motor you want separate control of the field current (or "excitation"), so a shunt-wound (or separately excited, a.k.a. "SepEx") motor configuration would be more suitable. Of course SepEx controllers are twice as complex (with separate rotor and field winding control), and uncommon.

I really like the idea of having the car handle like the Tesla's do . . . where as soon as you let off the accelerator, it starts heavily regen-breaking.
Why do people think that Tesla is the only builder of electric cars? Every production EV does regenerative braking when the brake pedal is pushed; likely all of them (including Tesla, but also Nissan, GM, etc) do some regenerative braking when the accelerator pedal is fully released. Tesla does less of this than others, perhaps because the base versions of their cars are rear-wheel-drive, and strong rear-only braking is unstable.
 

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As I have mentioned, we have a habit of off-roading with our RV, and I have oft-wondered about turning it into a 4WD. This video was inspiring to me:
https://www.youtube.com/watch?v=3ZHCrXu3vus

He's proposing that wiring DC motors in electrical series might be an effective solution for a sort-of built-in traction control in a 4WD application. He states P = V * R^2. If one wheel suddenly lost traction, it's resistance would drop dramatically, and then the other wheels would take-up all that extra ampereage/power. Any thoughts on if this principle might work?
I didn't listen to the audio to go with the fuzzy video, but I'm pretty certain that you should just ignore this guy.

No, power is not the product of voltage and resistance squared. It is the product of voltage squared divided by resistance (because P=VI and I=V/R, so P=V^2/R)... and even then, only for a resistor. A motor is mostly an inductor, not a resistor.

It is not obvious to me that a DC motor under less mechanical load would have lower electrical resistance. Thinking of this another way: torque depends on current, so with series wiring forcing both motors to flow the same current (one can't "take up extra amperage" from the other), they will produce the same torque; if one is freely spinning wouldn't it speed up, taking more of the voltage and taking over the available power?
 

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One unrelated thing I wanted to ask you all~

My friend/business-partner sent this to me:
https://docs.google.com/document/d/1xuMcEpAeLvgCBqVl7vX0HQwVXvbwWAGQO2-GqKbrauY/edit?usp=sharing

Looks like a perpetual motion machine to me? They say "no friction" but there are chains and gears in there. . . lol! Anyone who knows more about generators/alternators etc want to help me eat this thing apart? :D
Please move this perpetual motion crap to the thread dedicated to this stuff: Alternators, Free Energy, Perpetual Motion, Over Unity and all that.... I only skimmed it quickly, but it has the typical elements of a perpetual motion scam, with both flywheels and "magnet power" for bonus points, complete with what appears to be an associated pyramid scheme of fraud. As usual, there is valid technical content (in the description of energy sources) to make it look legitimate, before it proceeds into complete bullshit.

I would question whether anyone who is really your friend would try to get you to buy into this fraud. It is possible that he has been genuinely fooled, but it's pretty blatant perpetual motion crap.

Your explanation might also help slightly as I wonder about the feasibility of using a DC motor back emf to work a regen-breaking situation. . . ?
Since the whole thing is a fraud, I don't think there is any point in trying to learn about legitimate motor control techniques from it. Any idea introduced in this document is more likely to be misleading than to be a good starting point for technical education.
 

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On a semi-related note (maybe someone can help me with a better thread for this type of thing?) I took a ride on a vintage diesel electric train yesterday. A vehicle weighing over 700k lbs, with steel friction to boot, was being driven by 2 150hp electric motors. Giant diesel generators pump out 600V, at (I assume, since the conductor only knew the horsepower) about 224kW. They said they use about 10 gallons of diesel fuel for their 45 minute round trip. I rough calculated that it would require about 15 30kWh battery packs to do the same mission without the generator. :p It had me wondering though . . . would 3 of my Nissan Leaf's really be able to pull that whole train?!??. . . you know, 10mph on flat ground, like the little diesel electric yard engine was doing *the wonder of electric motor torque
If I have my math right burning 10 gallons of diesel can deliver about 400 kWh of heat energy, but if the diesel engines and generators are 30% efficient that's only 120 kWh of electrical energy. Maybe only five 30 kWh battery packs?

If you're willing to accelerate gradually - and train acceleration is very gradual - you don't need much power. A sports car, a light pickup with the optional engine, a typical heavy pickup, a medium-duty truck, and a older highway transport truck - all will have about 400 horsepower engines, each getting the job done but at very different rates of acceleration. Of course the larger vehicles use heavier engines, because those engines must work hard for longer, not just in short spurts.

The trick is having a transmission which can run at the required speed ratio, and a heavier load makes it more important to get close so more ratios are needed. A generator and motor set is a continuously variable transmission with an infinitely low lowest gear. The only special thing about electric motor torque is that it is available down to zero speed... just like a hydraulic motor.

Three of the motors from typical modern EVs could certainly move a lot of train; the challenge is to ensure that they can work hard continuously, which is largely a matter of cooling. Nissan rates their motor relatively conservatively (80 kW isn't a stretch for that size of motor) so three of them driving a train isn't unreasonable if geared appropriately. On the other hand, if you think single small Tesla motor can do it (because it is rated for two or three hundred horsepower), you'll probably find that you're mistaken about one minute into the trial.
 

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I had another talk with my welder, and I am leaning further and further in the direction of doing a full Leaf-Sharo cutaway ~ essentially cutting off the back half of my 2013 Nissan Leaf, and marrying the front half, including drive-train and drivers compartment intact, onto the back-half/living compartment of my LeSharo. Here is a really terrible mock-up of what this might look like, including a 12" lift on the back leaf-spring suspension of the LeSharo (which will also make extra room for mounting batteries underneath)
You wouldn't really keep the Renault part of the LeSharo (the cab), would you? Without the cab (just keeping the living part of the LeSharo as you said), and with only the front seat area of the Leaf retained, even just the Leaf battery would extend way under the living area... I hope you've realized that.

But really, a foot of lift? At this point, you could use any travel trailer body that you like, and mount it on a custom frame... it would avoid chopping up a LeSharo, and not be any more work.
 
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