I need acceleration, not range or top speed.

0

0to60

10 µW
Joined
Apr 29, 2022
Messages
5
First post.
I've learnt a lot from this board, I'm trying to find a solution to the following. There's a vast amount of knowledge here, and I'm hoping I can find a solution to the following. I'm building an electric scooter (vespa type), not to ride on public roads, purely to demonstrate the aggresive nature of electric acceleration. My strength is design and fabrication and my weakness is an understanding of volts, amps and watts. I'm at the point where I'm designing battery/controller compartments and I need help. I want this thing to be able to accelarate hard. Top speed isn't that important to me, 70KPH is fine. Range also isn't an issue, 20 minutes of run time is all I really need. Of course my top priority is weight. From a design standpoint, I need a 12" rear hub motor that runs a 130/70/12 tire, I can't really deviate from that. Right now, I'm looking at an 72v 8000w QS260 12" V4 hub, with an 72v 8000w ND72850 controller. My question is what type of battery design would be best to accomplish my goal? Everyone seems to be looking for top speed and range, I'm not. Torquey acceleration is what I need. Batteries get very heavy when range and 120KPH are needed. What I'm looking for may not be possible, but I'll be damned if I give up without giving it my best. Cheers to all who offer any advice.
 
Largest possible motor in smallest possible wheel with the most powerful controller and a light high voltage and high current battery pack built of smaller lipo pouches with max c-rating is the key to get what you want. Lighten your vespa as much as you can off course :thumb:

Rovii gsx-r drag race thread and jonescg battery building and his sport racer are good threads to read up on

I've looked at this motor before:
https://www.alibaba.com/product-detail/yuma-motor-12inch-15kw-dc-hub_1600261173520.html

350Nm in a 12" wheel if you believe the specs
 
For what scooter/motorcycle/moped?


larsb said:
I've looked at this motor before:
https://www.alibaba.com/product-detail/yuma-motor-12inch-15kw-dc-hub_1600261173520.html

350Nm in a 12" wheel if you believe the specs
Click to expand...
 
Your motor controller phase current seems too low to saturate the motors magnetics. If you really only want bursts of extreme acceleration, I would upsize the motor controller.
 
I love my recycled 25Ah EV cells. They just dont quit. Power for days and high charge rates.... they laugh at 10C all day. 500A out, contin, without any damage, long term, ( they last 10 years) is easily possible in a 2p, 50Ah pack. Peaks over 1000A easy.




liveforphysics said:
Your motor controller phase current seems too low to saturate the motors magnetics. If you really only want bursts of extreme acceleration, I would upsize the motor controller.
Click to expand...

850A is not enough? Huh I would have thought that could make for some good accelerations.

A friend of mine ( 14kV stator) just went, installed, and tested the 1800 phase amp modela nd he said it got him under 3 sec, 0 to 60mph.
 
larsb said:
Largest possible motor in smallest possible wheel with the most powerful controller and a light high voltage and high current battery pack built of smaller lipo pouches with max c-rating is the key to get what you want.
Click to expand...

Confirmation of my thoughts! And yes, power to weight vs strength to weight is my top priority.
 
liveforphysics said:
If you really only want bursts of extreme acceleration, I would upsize the motor controller.
Click to expand...

Got it... maybe not? for short shots of power, overpower the controller to the motor.
 
DogDipstick said:
I love my recycled 25Ah EV cells. They just dont quit. Power for days and high charge rates.... they laugh at 10C all day. 500A out, contin, without any damage, long term, ( they last 10 years) is easily possible in a 2p, 50Ah pack. Peaks over 1000A easy.
liveforphysics said:
Your motor controller phase current seems too low to saturate the motors magnetics. If you really only want bursts of extreme acceleration, I would upsize the motor controller.
Click to expand...

850A is not enough? Huh I would have thought that could make for some good accelerations.

A friend of mine ( 14kV stator) just went, installed, and tested the 1800 phase amp modela nd he said it got him under 3 sec, 0 to 60mph.
Click to expand...

Another thing to explore, cheers
 
I've ordered a Qs260 12" V4 10kw hub motor, plus an ND721200 controller. I'll need to source a fairly large amount of pouches to achieve my goals, but we're on the way. Frame strengthening is being addressed, and the front (Yamaha) and rear (misc amazon etc) suspension are coming along. Will be on Metzeler Roadtecs 130/70/12 rear and12/90/10 front. With the right battery config, should be fun.
 
Any updates on this? Curious how many phase amps you are running and what rpm/volt or kv the motor is.
 
Will be really interested in the battery solution for your set up.

I was looking at a similar strategy, acceleration over range.
I have a QS260 10KW 96V 12 inch V4 hub motor sitting on a Pirelli Rosso 130/70/12 high performance tyre.
Working with a FARdriver 961200.
Still trying to figure the battery strategy out which currently would be 50kg unless I shrink the P..
I was at 26S21P using P42's. A whopper battery..
My motor states 350Nm of torque which is mental and will need some tuning to get that power down and not flip the bike easily.
You also really need to consider the chassis with such forces.

0to60 said:
First post.
I've learnt a lot from this board, I'm trying to find a solution to the following. There's a vast amount of knowledge here, and I'm hoping I can find a solution to the following. I'm building an electric scooter (vespa type), not to ride on public roads, purely to demonstrate the aggresive nature of electric acceleration. My strength is design and fabrication and my weakness is an understanding of volts, amps and watts. I'm at the point where I'm designing battery/controller compartments and I need help. I want this thing to be able to accelarate hard. Top speed isn't that important to me, 70KPH is fine. Range also isn't an issue, 20 minutes of run time is all I really need. Of course my top priority is weight. From a design standpoint, I need a 12" rear hub motor that runs a 130/70/12 tire, I can't really deviate from that. Right now, I'm looking at an 72v 8000w QS260 12" V4 hub, with an 72v 8000w ND72850 controller. My question is what type of battery design would be best to accomplish my goal? Everyone seems to be looking for top speed and range, I'm not. Torquey acceleration is what I need. Batteries get very heavy when range and 120KPH are needed. What I'm looking for may not be possible, but I'll be damned if I give up without giving it my best. Cheers to all who offer any advice.
Click to expand...
 
If you really don't care about range, check out Headway LiFePO4 batteries from batteryhookup.com. I was going to use them in my build, but decided I wanted range. Theyre supposed to be rated for 200A continuous discharge, and they're cylindrical so they don't need compression.
 
larsb said:
Are headways still around? I’ve seen quite a few puffed and busted over the years.
Click to expand...

I haven't used them personally, so I can't vouch, I just got drawn in by the 200A rating. But even if it's an accurate rating, I would never use them at that rate on a regular basis. Perhaps I would use 2p and draw 300A, for example.
 
This is just for one version of their cells, but you can find specs or discharge curves for all of them around the web. This one shows that at 10C (100A) this 10A cell sags to nearly 2.5v.
http://www.litrade.de/pub/HeadWay%20LiFePO4%2038120__%20Specifications1.pdf
Even at only 1C (10A) it sags more than a couple tenths of a volt, and 30A half a volt.

So, let's randomly say you needed a 30s pack for about 100v "full", and you need 100A from it to get 10kw of power (100v x 100A). Well, at that rate, with a 1p pack, it would sag down to only 75v and only give you 7.5kw of power. A 2p pack would still sag 30 * 0.5 = 15v, down to 85v and only give 8.5kw.

So if you need acceleration power, and not range, so the smallest lightest pack you can fit would be best to not have to accelerate as much mass. That means one that doesn't sag in voltage much, so you get the most watts for the mass.
 
I'm curious, can the biggest possible hub motor that fits the perfect rim for the tire/frame out perform the most powerful conventional type motor that will fit the same frame? I know that for handling, a mid drive will beat a hub everytime.

What I'm thinking is that more copper might be able to be stuffed in a regular motor than in a hub motor seeing as how said hub motor needs to be in the smallest sized wheel that will still allow a big enough tire 'footprint'? I would think that it would be possible to cram more copper in the mid drive, because there is more room for the motor in the frame than in the wheel.

More copper = more acceleration :idea:
 
You must log in or register to reply here.

Similar threads

P
Questions about emotorcycle battery and motor
Replies
12
Views
526
Dui ni shuo de dui
Dui ni shuo de dui
T
CA v3 limiting power even when I raise the limits.
Replies
3
Views
398
amberwolf
amberwolf
H
    • Like
1989 Kawasaki EX500 (Ninja) - Second build, slow and steady
2 3 4 5
Replies
111
Views
4,744
harrisonpatm
H
C
  • Solved
VESC Tuning Advice, Poor Acceleration compared to other controllers
Replies
6
Views
2,571
shaggy_rogers
S
M
Problems with Votol Em200sp and low acceleration.
Replies
2
Views
801
stan.distortion
stan.distortion
Back
Top