E-Scooter project build. 50 kw peak (video online page 4)

ok probably not 50kw but i try!

hello crew,

i will start to build my first elektric scooter tomorrow and like to let you guys be part of this story.


some ideas in my mind...
- Brushless hub motor 72V
- Kelly controller 550A peak
- custom fan cooled 21s BMS 600A peak, 3x cellog extern monitoring, 250A charging option (if i find a source can handle that )
- self build charger 88V / 50-60A (i think its a good compromise to charge fast enough but dont abuse the cells too much)
- custom lipo pack 88,2V fully charged with 70Ah or maybe 105Ah

status until now: FINISHED
frame without motor, controller and battery is on the way to me and should arrive tomorrow.

parts ordered and shipped soon:
motor
controller
battery
300mm brakes
suspension
white LED gauges für controller, battery and motor temperature



if you guys interested i will keep posting the full build here with photos and some videos of my progress

UPDATE: scooter is done and used over 15000km. running perfect and it kicks asses!

sounds badass! I'd love to see how this project progresses.

niiiiiiiiiice work 8)

What controller are you going to get?
EDIT: Just saw it says Kelly

Guessing by the boxes in the background you are located in the mainland

hell year i am in wonderland here! living in shenzhen china.
but the photos with boxes in background are not from me. just use what the factory gave me.
battery factories and hub motors everywhere. just walk out my door and visit all company. later i will test these parts and make a request to these companies for you guys. i specially want to have a close eye on the NEC battery cells.
the bike will arrive in 2 hours and i will make some photos.

Cheers°

THE ARRIVAL











already start taking it apart. battery box seems pretty big. we will see wether i can fit that 70Ah battery inside.
now all the fun can start

Do you have a weight for the crate you got? I'm curious about the scooter weight without the battery or motor wheel. You'll want to include a 3rd temp gauge, the most important one if you're running high power into a hubbie. That's motor temp.

It sounds like you have distribution plans if things work out well, so I'd suggest toning it down on the numbers until you have some. Kelly controllers are rated in terms of phase current, which never peaks at full duty cycle due to current limiting, so that times voltage isn't your Kw's. You need battery current, and you also need the voltage under load. That still only power input, not power out like motors are rated, but at least get a real number.

Send extra on the controller, because the hubbies capable of handling the highest currents generally have very low inductance, and which tends to pop controllers like popcorn.

It sounds like you've got a pretty extreme BMS. Out of curiosity, why does the primary current flow through the BMS? That makes them far more expensive than necessary, and puts it under such stress that it's temperature needs to be monitored. A BMS needs only to monitor voltage of each series group and trigger actions for the controller based on the cell level info. I see no need to pass main current through it. Sure it's done that way for low power ebike BMS's, but that's easy and the currents are low enough for cheap parts. At the power level you're talking about, the BMS actually adds stress to the system due to the added resistance and inductance between the battery and the controller.

Even though I believe you're unrealistic with the 50Kw, I hope you end up getting there, which will really prove out your battery and motor choices. Any ideas yet on which way you're going to go regarding a motor. I'm green with envy about you being right there where the action is, and if I was 20 years younger I'd already be there with you.

John

Wow...that is one aerodynamic scooter. It has a seriously steep angle on the nose.

Love it!

high john,
thanks for all these helpful infos!
yeah... i know i wont get 50kW on the wheel but it would be great if we are getting in that direction.

the point with BMS is true. now when i think about it i will send the message to my battery supplier and stop him from building that BMS because its really expensive. if i already monitor every cell i can set alarm and just stop before the pack is fully discharged.

weight of the scooter empty now should be around 50-60kg. i will check it later with my weight.
battery with 70Ah is 36kg.
hub motor not sure but around 16kg.
then we have the controller and some other electric features i want to build in later. but also change parts like suspension and brakes to higher quality and lighter...difficult to guess yet.
now i am still figuring out where this adventure take me. i start to build it. use a 120-200A controller first for tests and see how everything work together before i add some more serious power.

thirt temp sensor. in the motor we have already build in sensor but i still try to find out what display i can use to get temperatur out to my handle bar. the kelly already use it to reduce power but i still love to see some numbers on my handle bar too. maybe you guys have any idea to make it possible?

after all this is a fun project and can never compare to some real awesome builds i see here before.
i pay my respect to all of you guys building motorbikes or bikes from scratch!
but i still think it is maybe interesting for some of you so i want post everything about this build 8)

EDIT: it may look so steep because there is no rear wheel on now? actually i think its not so aerodynamic
but it looks really beautiful! i love it.
@john: motor will be quanshun 72V 8000W 100-130km/h stator. (lower torque/higher RPM)

every helpful advice is welcome!
thanks again john

yesterday i took everything apart until late night. battery box seems really much bigger than i expect before. now figuring out wether i can change the 70Ah 21s2p pack to 21s3p and get 105Ah for some nice range.

stay tuned!

I didn't mean no BMS, but it's relatively simple to use a low current BMS. Then have it cut off the controller when a cell hits the single cell LVC instead of cutting mains power to the controller.

If you have a 10k thermistor installed as your temperature sensor, which is simple to do after the fact as long as the factory wires the motor for a sensor, then you can use some nice features of the Cycle Analyst 3. You'll have a temp display on the CA3 itself, and do cool things like dial power back when the motor temp reaches a certain threshold, and cut power completely if the temp continues to rise to the cutoff threshold.

For sensor installation I suggest not following the ES crowd who mistakenly try to stuff their temperature sensors in the copper. That results in false overheating notifications, because copper temps are much more volatile than stator temps, but a short spike doesn't mean the motor is overheating, because the stator steel could be relatively cool and quickly sink away heat from the copper. Sensors on the stator steel 5-10mm away from the copper is pretty standard for how the motor factors install their thermal sensors.

Those Adelin brakes look pretty sweet. Any idea how the perform? Nice build

steam25 said:

..turn on the light and horn goes off.

Click to expand...

This isn't a fault, it's a "feature" for busy Chinese roads

where did you get your headlight?

directly from the chinese factory around here.
they are waterproofed and really good.
terrible bright. mine is 7500lumen and far more bright as normal car lights with high beams on.
you can choose from flood to beam. or mix them like you prefer.
running from 9-30 volts and drain only 1,9A out my bike battery.

from 2 up to 40 crees in row or double row.
start at 10$ each. mine with 80W cree cost around 45 $ ?

that's excellent. I was thinking of getting these:
http://www.ebay.co.uk/itm/2000-lumen-5-Modes-Dual-Head-Bicycle-light-Headlamp-With-2-Cree-XM-L-U2-LEDs-EA-/350918470286?pt=UK_SportGoods_CyclAcces_RL&hash=item51b45eea8e

XM-L U2 are the latest led light for sale.

But maybe I can get one of your from china? How can I buy that?

i often send LED lights and other cool stuff to play to friends.
lights you see in ebay never have 2000 lumen. i would go for 1000-1200 max because small reflectors. these are pretty bad fakes too. i have original here in my room and use them on my bikes. dual and TRI configuration with battery indicator. if you want light for your ebike you can get one. if you want something for a FAST bike. lets say 50km/h+ they are not good enough.
where you wanna strap these on? i can give you good suggestions about LED lights because its part of my job to test newest generation of LEDs. 8)
maybe you can send me PN. i try help you.

btw:
BACK TO TOPIC
i took my rear light apart and solder some red color LED stripes inside the empty silver part. now i am getting some nice wide red lines beside the main brake light.

Temperature gauges cant fit in cockpit because i want my volt display or cycle analyst at this place.
i found that the old gasoline refill cap is a perfect spot to install both temp displays.
then i also dont need to enlarge the wires cause they are little short. now they can fit in my battery and BMS or CONTROLLER.

what should i monitor? BMS or Controller??? please help me out guys

hey guys and silent reader.
can somebody give me some suggestions how to make the temp gauges waterproof?
any ideas?

Perhaps attach/glue a piece of thin polycarbonate over them with some sort of trim ring?

steam25 said:

Now they can fit in my battery and BMS or CONTROLLER.
what should i monitor? BMS or Controller??? please help me out guys

Click to expand...

Hello, I would go to monitor the controller or the motor temp. Do you think it will be readable with day light or sun ?