# Can I use a Nissan Leaf EM47 in a motorcycle?



## remy_martian (Feb 4, 2019)

It's not how big it is, but how you use it.

You've said nothing about performance specs you want out of it. 

You will be weight restricted for battery and that will trade for motor weight -- the Leaf motor is fairly heavy for a bike, but again that all depends on your specs on whether it's too heavy.


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## MoodyDude27 (3 mo ago)

Gotcha, that makes sense. I'd probably want to limit the speed to around 60-70 mph to start out, but it would be nice to have some extra capability once I get more comfortable so I don't have to upgrade it as much in the future. I'm more concerned about range, but that mostly comes down to battery size, right?


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## remy_martian (Feb 4, 2019)

Acceleration and minimum range have to be spec'd, not just top speed.


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## remy_martian (Feb 4, 2019)

Everything interacts, so "upgrade" usually means building another bike, effectively, from the ground up.

A lot cheaper to do it once to what you want, or like @Functional Artist does, build new machines each time.


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## Electric Land Cruiser (Dec 30, 2020)

It will work the EM57 is lightweight and compact. The issue is that you need to give it at least 300 volts, preferably 350+ to get anywhere near the rated power and usable RPM range. I think it would be tricky to build a small but high voltage motorcycle pack at that voltage.


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## remy_martian (Feb 4, 2019)

It's compact and lightweight for a *car*.

For a bike it's massive, especially if it needs to go 60mph and range and handling are important.

58kg vs 16 kg for a rightsized motor is huge weight difference in a motorbike.









Motenergy ME-1306 Brushless DC Permanent Magnet Motor


Motenergy ME-1306 Brushless DC Permanent Magnet Motor




evdrives.com





That motor cost, new, is less than what a clapped out EM57 costs.

That's not counting weight of a "primary" reduction gearbox if needed.

The pack voltage for the EM57 is also awkward in a bike, though not inpossible.

Let's see what @Functional Artist says after he's had his morning coffee.


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## kennybobby (Aug 10, 2012)

If you can build it--they will ride.


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## remy_martian (Feb 4, 2019)

First time I've seen someone stuff an H48 engine into a bike....


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## MoodyDude27 (3 mo ago)

remy_martian said:


> Acceleration and minimum range have to be spec'd, not just top speed.


I want a minimum range of about 75-100 miles, and 0-60 of <15 seconds. Idk how realistic that is for an electric motorcycle, like I said, I don't have much experience. I realize the Leaf is probably overpowered for what I'd like to do with it, but my thought was if I can make it happen it would probably give me better performance once I'm comfortable relaxing the limits more. Especially if I can salvage one from a junkyard for less than what they're selling for on eBay. How would I math out how much power it takes for a given weight and target acceleration? What should I expect the finished bike to weigh?


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## MoodyDude27 (3 mo ago)

I should probably also say what my budget for this project is, huh? I've got about $4000 I can throw at this, and I'm getting the bike for $500. Of course, I'll gladly spend more time if I can save money, so if I have to salvage an electric motor and fix it up I'm not afraid to do that too.


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## MoodyDude27 (3 mo ago)

Just need to figure out what I need to look for...


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## Functional Artist (Aug 8, 2016)

remy_martian said:


> It's compact and lightweight for a *car*.
> 
> For a bike it's massive, especially if it needs to go 60mph and range and handling are important.
> 
> ...


I have to work ...sometimes  

If were talking about a bike like this
Honda CBR 1000F (1990) technical specifications
...have you thought about, where you could mount an EM57 (physically mounting & also, connecting the power train)
...& a batt pack big enough to power it? 
...& also, a batt pack "big enough" to provide a 75–100-mile range? 
...& keep the plastic "body work" too?

IMO, the 12kW motor Remy referenced would be a better (more practical) choice (for a motorcycle)
...& "if" powered by (for example) (2) 48V 50AH Chevy Volt modules, connected, in series for a (~96V 50AH pack) you should easily be able to attain highway speeds (not sure of range) 

Real world info:
I run my ElMoto's 8kW motor at 48V (top speed ~48MPH)
...& when powered by (2) 48V 50AH modules (in parallel to make a 48V 100AH pack) I have a ~50 mile range.

Cost ~$3,000.00
Fun Level -Priceless


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## MoodyDude27 (3 mo ago)

Functional Artist said:


> I have to work ...sometimes
> 
> If were talking about a bike like this
> Honda CBR 1000F (1990) technical specifications
> ...


Alright, so there have been some great points made in this thread so far, and I really appreciate all of your help. To summarize, if I understand correctly, the Leaf EM57 is too big and heavy to get significant benefits out of it in a motorcycle application, once the battery pack is factored in as well. (As I've been doing more research, the battery pack seems to be the more limiting factor in terms of power and especially cost.) For this project, and especially since I'm a beginner, I should be looking for something smaller and easier to work with.

I've inquired at a couple places here in the Spokane area that stock electric motors (Spokane Forklifts and BL Best Electricals), and will be visiting them to take a look at what they have probably on Thursday or Friday. BL Best told me they might have some motors that they can sell me for a couple hundred (just needs some TLC), so we'll see. Spokane Forklifts hasn't gotten back to me yet, but they did say most likely they won't have anything rated higher than 48v. I'll try to look for something in the 12-20kW range, but size seems to matter as well, so I'll have to balance that. I haven't seen the bike in person yet, I'll be taking a look at that on Wednesday.

I'm one of those people that can tend to bite off more than they can chew in the name of pinching pennies, so I appreciate having people who know what's up giving me solid advice! My plan for this project is to turn the bike into a cafe racer, so I probably won't keep all the plastic body panels.

Battery building seems like a whole 'nother can of worms, but at least I'm making progress here...


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## kennybobby (Aug 10, 2012)

Do a search and read Ripperton's electric motorcycle threads, he is a master builder of electric road bikes, dirt bikes, racing carts, etc. Also search for posts by Major.


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## Functional Artist (Aug 8, 2016)

remy_martian said:


> Everything interacts, so "upgrade" usually means building another bike, effectively, from the ground up.
> 
> A lot cheaper to do it once to what you want, or like @Functional Artist does, build new machines each time.


Um...I'd disagree (on both claims)

I started off running my ElMoto at 36V using (4) 12V 35AH SLA batteries
...(1) to power the 12V system (headlight & turn signals)
...& the other (3) to power the motor
(Top speed ~25 MPH & didn't keep track of the range)




1st upgrade (36V to 48V)
I installed a 48V to 12V voltage converter (to power the 12V system) 
...so then, I could use all (4) battery modules to power the motor at 48V
(Top speed increased to ~40 MPH & ~9 miles range)




2nd upgrade (Lead battery pack to Lithium)
I installed a 48V 50AH Lithium battery module (from a Chevy Volt)
...SLA pack ~140Lbs. to the Lithium module ~50 Lbs.
(Top speed still ~40 MPH but, the range increased to ~25miles)




3rd upgrade (48V 50AH battery module to a 48V 100AH battery pack)
I installed a (2nd) 48V 50AH module "in parallel" to make a 48V 100AH pack
(Top speed still ~40 MPH the range increased to ~50 miles)




4th upgrade (gear ratio adjustment)
I switched the 10 tooth drive sprocket, on the motor with the 13 tooth idler sprocket
...to change the gear ratio from 5:1 down to a 3.85:1
(Top speed increased to ~48 MPH but, the range seemed to decrease a bit to ~45 miles)





& 

All of my machines or "creations" are quite different 
...not just "upgrades"


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## MoodyDude27 (3 mo ago)

Ok, so the forklift place didn't have anything rated higher than 36V, and he said they don't like to run on anything less than 1000Ah. Looks like they're build solid, just not high-performance. I'll probably end up going with something from Thunderstruck in the end, unless QS motor offers me a pretty good deal, but with shipping it'll probably end up being more expensive anyway. It would be nice to go with a hub motor just because it seems easier to work with and would give me more space for the battery, but I also like the idea of being able to change the gearing when I need to. Any final suggestions?


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## remy_martian (Feb 4, 2019)

Front and rear sprocket are your ratio changes. 

If you've driven an modern EV, you come to realize that gear changes are a silly ICE thing.


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## MoodyDude27 (3 mo ago)

remy_martian said:


> Front and rear sprocket are your ratio changes. If you've driven an modern EV, you come to realize that gear changes are a silly ICE thing.


 Yeah, that's what I should have said, sorry


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## Electric Land Cruiser (Dec 30, 2020)

Hub motors are great for the reasons you mention but also greatly increase unsprung weight.


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## remy_martian (Feb 4, 2019)

There's an argument that a motorcycle hub motor is not much heavier than a shaft drive's ring and pinion, but yes tye added mass is a problem for handling and for potholes.


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## MoodyDude27 (3 mo ago)

Electric Land Cruiser said:


> Hub motors are great for the reasons you mention but also greatly increase unsprung weight.


How does unsprung weight affect the performance of the motorcycle?


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## remy_martian (Feb 4, 2019)

It affects the handling performance - the ability of the wheel to follow the road surface. If the roads are paved and not potholed, and you're not blasting through turns, it doesn't matter a whole lot.


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## MoodyDude27 (3 mo ago)

remy_martian said:


> It affects the handling performance - the ability of the wheel to follow the road surface. If the roads are paved and not potholed, and you're not blasting through turns, it doesn't matter a whole lot.


Ok, that makes sense. For turns, do you mean the rear wheel would be more prone to losing traction?

Are there any other disadvantages to hub motors I should consider? I've heard they're less efficient at higher speeds since you're running them so close to their max capabilities. Is this true, or would that be the case with either motor type? I'd think you could just change the sprocket ratio for a mid drive to help with this issue.


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## remy_martian (Feb 4, 2019)

You need to look at the motor curves to see where the losses are. 

Back-EMF at higher rotational speeds is not a loss, which some "experts" seem to think is an "inefficient" place to operate the motor as they equate it to an increase in resistance ("cuz current goes down") - which it is not.

I'm not getting cornered (pun sorta intended) legally (anything on this forum is worth what you paid for it and requires due diligence to verify and appropriately assess risks) on your curves question. I stated where I believe they operate best. e-Bikes use hub motors without many horror stories that I've heard of....many without suspensions whatsoever. 

Arguably, a Harley hardtail has half its mass as unsprung weight 😂


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## MoodyDude27 (3 mo ago)

Cool, thanks! That definitely helps clear things up. I'll probably think it over for a while before I make my final decision, but once I purchase the motor, that's pretty much the end of the planning phase. 

I already spoke with a local company called Max Amps in Spokane that does custom batteries. They offer engineering services to help me design a battery pack to fit my frame and energy needs, and they're getting some new LiFePO4 cells in soon. If I need to do any modifications to the frame, I can ask my housemates that have already started maintenance training at our college. Looks like I'm all set, friends! Thanks for all your help!


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## remy_martian (Feb 4, 2019)

If you're going to build a bike, I'd stay away from high-mass, low energy density, tech.


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## MoodyDude27 (3 mo ago)

My reasoning for using LiFePO4 is because I have absolutely no desire to be sitting on a potential firebomb. I've seen way too many Li-Ion and Li-Po batteries explode to consider using those.


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## remy_martian (Feb 4, 2019)

You have not seen any explode, because they don't.

Maybe you should build a pickup truck?


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## MoodyDude27 (3 mo ago)

remy_martian said:


> You have not seen any explode, because they don't.
> 
> Maybe you should build a pickup truck?


I absolutely have seen Li-Ion and Li-Po explode, and personally as I use them in RCs. Also, remember the Galaxy phones a few years ago blowing up in people's pockets? Yeah, sure they don't explode...


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## remy_martian (Feb 4, 2019)

Your toys' batteries, their method of packaging into the toys, their thermal conditions, the way they are charged, etc, are not applicable to electric vehicles.

EV batteries do not "explode". That is a Facebook myth, and now I understand what communities it came from, as I've been scratching my head about the source of such nonsense after reading luddites' claims that EV's explode.


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## MoodyDude27 (3 mo ago)

Maybe true, maybe not. Fact remains, I'm not comfortable taking the risk. The chemistry doesn't change simply because the size increases. LFP are inherently more stable than NCA or NMC. Yes, they're less energy dense, but that also makes them less volatile. They can also last years longer than other chemistries, be charged higher and discharged lower, and can undergo vastly more charge cycles before experiencing degradation. If my range and performance suffers, so be it. I can wait until battery tech improves, but until then I'm not going to use something I don't fully trust. I would get LTO if I could find it, but I haven't seen much around.


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## thethaothientruong (3 mo ago)

MoodyDude27 said:


> I should probably also say what my budget for this project is, huh? I've got about $4000 I can throw at this, and I'm getting the bike for $500. Of course, I'll gladly spend more time if I can save money, so if I have to salvage an electric motor and fix it up I'm not afraid to do that too.


What is motivating you to invest $4,000 and only get $500?


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## MoodyDude27 (3 mo ago)

thethaothientruong said:


> What is motivating you to invest $4,000 and only get $500?


I'm purchasing the bike for $500, I have a total budget for the project of $4000


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