[Sulliadm]

Edit: I am aware that I will be making multiple builds, this will not by my last build. I currently needing help with this build specifically.

Hello all, I am wanting to build an electric motorcycle completely from scratch that competes with newer major brands in terms of performance. However, I realize that is a major hurdle for a first build. I have decided my first build should be a moped conversion so I can figure out how this will go. Here's what I have so far:

- 2007 Aprilia Scarabeo 100 which I believe the motor is shot in it but if I can get it working, I'd like to sell (2007 Aprilia Scarabeo 50/100)

- A battery pack from what I believe is a 2011-2015 era Hyundai Sonata (Hyundai Sonata Hybrid battery pack teardown)

After looking around, I found this hub motor that I'm pretty sold on for a first motor. QS Motor 17x1.6inch 2000W 260 35H V1.12 In-Wheel Hub Motor for E-Motorcycle

My thought process was I take the banks out of this battery, make sure they're working correctly and wire them up in 2s4p to get 60V and 21Ah total with a bank left over in case there's a bad bank.

I need some recommendations for a motor controller that supports regenerative breaking and BMS for this build. I also would like some advice on how to make this thing street legal (turn signals, headlights, brake lights, etc). Would I need a 2nd battery for that system or is there a way to wire that into the existing battery system?

 

[remy_martian]

1200Wh is too small for a motorcycle, imo, unless you're good with just taking it around the block between charges.

 

[Sulliadm]

1200Wh is too small for a motorcycle, imo, unless you're good with just taking it around the block between charges.

Yeah, the plan is to put a 2KW motor on a moped just to get the fundamentals figured out. Then we can scale up.

 

[remy_martian]

Nothing "scales up" - you can build skills, but it's a totally new build

 

[Jordan325ic]

On an typical build your 4 main components, battery, battery management system, motor and motor controller will be sized to each other, so upgrading one component won't provide much, if any benefit. Also the majority of the cost in shipping heavy components from China is the freight cost, not the cost of the item itself, and the difference in price between a '2000W' motor a '5000W' motor is fairly small. So you may as well just choose the power level you want instead of buying twice. To match the power of a 100cc engine you probably want 5kw motor. However buying a '5kw' motor doesn't mean you're going to get 5kw, the controller, BMS and battery all have to be able to provide that power.

Regarding which motor controller, the motor company you listed (QS) offers all of their motors with a matching controller, so that's the obvious choice. They also offer 'kits', which include a few other accessories but personally I don't think add much value. The motor/controller combo is what you want. Those are great motors though.

What you really need to do when starting a build is decide what your desired goals are, and build backwards from there. What kind of cruising speed are you looking for? What range?

 

[Sulliadm]

On an typical build your 4 main components, battery, battery management system, motor and motor controller will be sized to each other, so upgrading one component won't provide much, if any benefit. Also the majority of the cost in shipping heavy components from China is the freight cost, not the cost of the item itself, and the difference in price between a '2000W' motor a '5000W' motor is fairly small. So you may as well just choose the power level you want instead of buying twice. To match the power of a 100cc engine you probably want 5kw motor. However buying a '5kw' motor doesn't mean you're going to get 5kw, the controller, BMS and battery all have to be able to provide that power.

Regarding which motor controller, the motor company you listed (QS) offers all of their motors with a matching controller, so that's the obvious choice. They also offer 'kits', which include a few other accessories but personally I don't think add much value. The motor/controller combo is what you want. Those are great motors though.

What you really need to do when starting a build is decide what your desired goals are, and build backwards from there. What kind of cruising speed are you looking for? What range?

Speed: 35 mph
Range: 125 miles

 

[remy_martian]

1.2kWh pack, presumably 1200W motor power @35mph is....35miles of range.

Where is the magic happening, or is this a 125 mile long hill?

 

[Sulliadm]

1.2kWh pack, presumably 1200W motor power @35mph is....35miles of range.

Where is the magic happening, or is this a 125 mile long hill?

I'm going to have to add a lot more battery capacity, I know. The motor I'm looking at is a 2KW motor that has a maximum speed of 35mph. So I'm looking at what... 6-8KW of battery capacity? Or in this case, in this 72V configuration, I'll need 83-111AH?

 

[Jordan325ic]

On my similarly sized electric motorcycle I use roughly 2kw to maintain 35mph. So you're right you would need 7kwh of battery for that kind of range. That's going to be a difficult fit, and in general 'adding capacity' is not as simple as bolting on more batteries. Batteries need to be very closely matched, so it's a good policy to buy used batteries all out of the same pack, not buy one module now and another module in 6 months. And generally your entire BMS / battery enclosure system will need to be re-designed generally.

Why 125 miles? Do you really have a 100 mile commute? Range is by far the biggest challenge on an electric motorcycle for packaging/aerodynamic reasons, better to be a bit more realistic. I have a 40 mile highway commute (one way) and I designed my system to do 50 miles, that was the biggest buffer I could manage. I spent a bit more on a 'fast' charging solution and I can do 100 miles if need be. 100+ miles on a charge would be great, but...

 

[Sulliadm]

Basically some co-workers and I are working on converting mopeds as a "class project" (basically we're all apprentices for Amazon's robotics program and our supervisor wants us to put all of the skills together from school as an unofficial 'final project'). The goal is to make it competitive to modern products commercially available. None of us think we'll be able to match it in terms of speed or efficiency so we're going to beat them at range. Hence the lovely pickle we're in.

 

[Functional Artist]

This maybe helpful to your project
...or maybe not

 

[Functional Artist]

Here is part II

Yes, there's more

* In the video I incorrectly state that the 24V 50AH 6S3P module has 36 cells.
It does not, it actually has 18 cells. (3 x 6 = 18)

It's big brother the 48V 50AH 12S3P modules has 36 cells (3 x 12 = 36)

 

[Functional Artist]

Ummm...why don't I have an edit button?
Everyone else seems to be able to edit their posts (at least for a short time)

 

[Jordan325ic]

Basically some co-workers and I are working on converting mopeds as a "class project" (basically we're all apprentices for Amazon's robotics program and our supervisor wants us to put all of the skills together from school as an unofficial 'final project'). The goal is to make it competitive to modern products commercially available. None of us think we'll be able to match it in terms of speed or efficiency so we're going to beat them at range. Hence the lovely pickle we're in.

Cool! But I disagree. Look at commercial offerings, they are extremely fast (acceleration that is), and efficiency? Measured how? Electric propulsion is 85-95% energy efficient. ICE maybe 25%? Where electric motorcycles suffer is range, by nature of the design. You could build a wheelie machine more easily than a long-range bike. Batteries just don’t have the energy density to match gasoline.

 

[Sulliadm]

Cool! But I disagree. Look at commercial offerings, they are extremely fast (acceleration that is), and efficiency? Measured how? Electric propulsion is 85-95% energy efficient. ICE maybe 25%? Where electric motorcycles suffer is range, by nature of the design. You could build a wheelie machine more easily than a long-range bike. Batteries just don’t have the energy density to match gasoline.

That's what I mean. We're using off the shelf/salvaged parts so being a brand new electric scooter that's already 90+% effecient isn't possible. So we were hoping beating the range would be. The idea was to salvage a couple of those batteries I mentioned before (72 cell pack from an old sonata hybrid), and keep the cells together into matching batteries (20s1P) so we wind up with 3 72v 5A batteries. Then wire them in parallel to one another as needed. If we need more batteries, find another lithium ion battery system from a car, and do the same, making sure they don't ever cross packs. Also each 20S1P battery will have its own BMS connecting to the cells and the other batteries so by seperating them out that way, we're hoping.

 

[MattsAwesomeStuff]

Ummm...why don't I have an edit button?

Shortly after you post, there's a grace period where you can edit almost every post if you wanted to.

Beyond that, you're allowed 10 edits per week.

There is no way to know how many edits you're at.

There is no way to know how soon you'll be able to edit again.

The goal of this is to prevent the common spam technique of buying or hacking someone's account, then going through 1000 of their old posts and editing them to include SEO stuff. Especially on old threads that aren't posted to, since editing doesn't trigger a recentcy event, chances are no one would ever notice, and they'd still reap the SEO benefits of that behavior.

Rather than flag this intelligently, they've Vertical Scoped it as usual. They've chosen a methodology that is irritating to legitimate users, and, not really any drawback to an automated system (that can just do 10 a week per account, automatically, with an extra click of a button on setup).

I've asked for it to be changed to something more useful, but, as usual, hello and welcome to our brick wall.

 

[remy_martian]

A 150-180mpg gas scooter (or Honda Cub) has the worst CO2 benefit for electrification and this form of mobility is typically owned by the working class living in places where there's nowhere to plug in -- that means a factory worker carrying the bike battery up 4 or 5 flights of stairs to a rented room after a 12 hour shift. That, alone, limits your pack to 10kg or so, as does the affordability of the scooter, since range is a major cost adder. Most of these scooter operators need to run a few dozen km a day, unless they are a motorcycle taxi.

You will never compete with a gas scooter carrying an extra gallon of gas in a can - futile. Probably is why your supervisor works at Amazon and not Zero Motorcycles.

Sounds to me like you might be doing a sidejob for him/her to take to SE Asia for motorcycle taxi or food/Amazon delivery use.

 

[Functional Artist]

Shortly after you post, there's a grace period where you can edit almost every post if you wanted to.

Beyond that, you're allowed 10 edits per week.

There is no way to know how many edits you're at.

There is no way to know how soon you'll be able to edit again.

The goal of this is to prevent the common spam technique of buying or hacking someone's account, then going through 1000 of their old posts and editing them to include SEO stuff. Especially on old threads that aren't posted to, since editing doesn't trigger a recentcy event, chances are no one would ever notice, and they'd still reap the SEO benefits of that behavior.

Rather than flag this intelligently, they've Vertical Scoped it as usual. They've chosen a methodology that is irritating to legitimate users, and, not really any drawback to an automated system (that can just do 10 a week per account, automatically, with an extra click of a button on setup).

I've asked for it to be changed to something more useful, but, as usual, hello and welcome to our brick wall.

Hey Matt,
I actually don't have an edit button (at all)
...& haven't had one for a few years.

I don't think I've had one since I got banned from ElMoto (electric motorcycle forum) years ago
...& my account on this forum, got "froze" too (same owners)

 

[remy_martian]

It's in the three dots in the upper right corner of your posting's white text area.

 

[Functional Artist]

That's what I mean. We're using off the shelf/salvaged parts so being a brand new electric scooter that's already 90+% effecient isn't possible. So we were hoping beating the range would be. The idea was to salvage a couple of those batteries I mentioned before (72 cell pack from an old sonata hybrid), and keep the cells together into matching batteries (20s1P) so we wind up with 3 72v 5A batteries. Then wire them in parallel to one another as needed. If we need more batteries, find another lithium ion battery system from a car, and do the same, making sure they don't ever cross packs. Also each 20S1P battery will have its own BMS connecting to the cells and the other batteries so by seperating them out that way, we're hoping.

Where do you plan on mounting the battery pack on your moped?

&

(3) 72V 5A(H?) battery (modules) connected "in parallel" create a 72V 15AH battery pack
...& 15AH isn't going to get you anywhere near 100 miles of range (even on a small scooter)

That's why I posted the Freedom Scooter videos (Food for Thought)

So, here is part III

&

Part IV