My Chinese E-Scooter

Joined
Jan 29, 2016
Messages
903
Location
Shanghai
Hello everyone,

I recently discovered your forum and didn't found any specific category in it to introduce myself, so I guess this one is probably the most appropriate to do so.

I'm a French guy living in China for a while, and I own this scooter for almost two years now. This machine evolved quite a lot since I purchased it, and I'm pretty proud to say that I made each of these modifications by myself :)

The original configuration was:
-battery: 60V, 20Amps, lead/acid (5 batteries)
-1000W no name controller
-1000W hub motor
-Performance: max speed around 45-50 km/h, zero to max speed achieved in about one hour and a half XD
-Autonomy: around 25 km while riding in "race" mode, about 40 km while riding more economically

Things I've changed or optimized:
-Complete strip down of the chassis, rewelding of each and every suspiscious joints. Then sanding and painting.
-Re wiring of the power lines in super thick battery jumping copper cables, to improve reliability, all wires are soldered and schrink tubed for reliability. My power lines are a bit overkill but they will never heat. :D
-Brakes changed: calipers, disks, tubes, etc
-Maxxis tyres
-New front fork and rear shocks
-Lithium battery: 72V 50Ah, LiFe. The battery had to be custom made, so it is splitted into two distinct batteries linked together. The BMS has been specially redesigned for me by the manufacturer to support 150Amps of draw. I unfortunately have no idea about the C rating (the information was not provided by my manufacturer). Total weight is about 35 kilos for the battery, half of it has been installed under the feets, the rest is under the seat. I had to build a custom stainless steel casing to fit all that power safely.
-Sine wave controller: I use the sabvoton 72V 150A sinewave controller. By far my favorite controller of all times among the ones I've already tested, just perfect about everything. Incredibly silent, very powerful, easy to wire, easy to link to the motor and to configure... I use it for a year now and it seems pretty reliable. My favorite feature of this controller is the fact that it is fully progressive and offers the exact same feeling of a gaz motor. It doesn't give you this ON/OFF feeling that you have with other controllers when you turn the throttle, this one is just the same feeling as what a gaz engine would provide. It is also very reactive, you don't have this annoying lag whenever you accelerate or decelerate which you can sometimes have with other controllers.
-cable throttle: I sometimes had problems with the standard throttle during heavy rain: the water would go inside and short circuit the potentiometer. I've switched it to a cable throttle, which allow you to put the potentiometer anywhere you want inside the scooter, so it's effectively protected against any kind of bad weather conditions. It works perfectly and also contribute to get the feeling of driving a gas powered machine.
-2000W Q.S hub motor, 55H magnets, Balanced version (a compromize between high torque and high speed versions).
-Water cooling system: since It can get very hot in China during summer and since my controller is located in a spot where there is basically no air flow, I had to set up a little watercooling to keep it reliable for long distances at high speeds. My watercooling setup is composed by 3 big aluminium heat exchanging plates fitting under the controller, a water pump, a conputer watercooling radiator, some automotive tubes and a little tank that I've 3D printed. It works perferctly no matter how crazy I run the bike even during the hottests days of the year.

-Performance: since the controller is fully adjustable, the performance can vary depending on the settings. The maximum speed I have reached so far was about 96km/h, but I believe I can go a little up to 100km/h with some fine tuning.
The acceleration from nor to 50km/h is less than 3 seconds, and I estimate it takes around 8-9sec to reach full speed. Here again, I think there is still some room to improve it a bit by some fine calibration of the motor and adjustments on some parameters.
-autonomy: Here again, it largely depends on the driving style. I can do about 50 km while driving crazy, 80 if I drive like a "normal, not insane" person, and for sure more than 100km if I drive like a granpa. I never had the patience to test the maximum autonomy at low speed and I actually don't care that much, since I have a tendancy to always run like I'm on a race track :D

This scooter is my daily driver, I have to do about 50 km each day with it to go to work, so I made a lot of efforts to have a very reliable and safe setup, sometimes affecting a bit theoritical performance, but overall the compromize I've made are really satisfiying. For instance, I've chosen LiFe batteries instead of LiPo considering the safety aspect in case of crash or catastrophic failure, despite the fact that they are heavier and somewhat less powerful. same thing about the watercooling, reliability over lightness.

So far I never had any issue with it apart for a faulty ball bearing of my hub motor, which was still under warranty.

I'll post some more pictures whenever I'll have access to my other computer, but meanwhile, here is what it looks like:


IMG_1843.JPG


IMG_1844.JPG

See you soon on the forum, if you have questions about my setup just let me know!
 
As promized, some pics of the build:

The two lithium batteries:
View attachment 16

A custom box to fit the bottom battery
2.JPG

The chassis almost ready
3.JPG

My first attempt of custom painting on the swingbar... Not so great :D
View attachment 13

The batteries and controller installed
5.JPG

My battery connector...quite massive stuff :D
View attachment 11

Battery power cables before soldering
7.JPG

And after:
8,1.JPG

Power lines installed on my scooter:
8,2.JPG

I've added a voltmeter on my dashboard to better monitor my autonomy:
9.JPG

10.JPG

The first attempt of watercooling:
11.JPG

The little 3D printed water tank:
View attachment 4

It used to leak a bit at the beginning but it works fine now. I don't recommend this method since the plastic can become a bit soft when water gets too hot.
13.JPG

14.JPG

Ready to start :)
15.JPG

My machine together with one of my friend's, which I've built too. His scooter uses lead acid batteries (72V 60AH) and performs quite well, despite its heavy weight. The controller is also a sinewave, from a different manufacturer, rated at about 200A.
16.JPG
 
Ça va? Very cool! That anderson power connector is epic though. Haha. Was in China for the past three years too.
 
SlowCo said:
Nice build photos.
If you get the chance could you make and post a ride video? That would be cool.

Unfortunately I don't own a gopro or any suitable camera...
I can try using my phone If I manage to find a way to attach it properly.
 
Hi guys,

After taking some time to read this forum, I realize that there are really a lot of very skilled people here!
I'm particularly impressed by the Lebowski controller project, which sounds amazing. I'll definitely give it a try whenever I can :)

For the moment, I have a question regarding a little improvement that I would like to make on my machine.
I believe that currently, my limitation could be the total current that my battery is able to deliver. Under big loads, the voltage can drop quite a bit and, while the acceleration is quite strong already, I would wish it to be even a bit more consistent.

I tought of using supercapacitors, to act like a buffer whenever the load needed is big enough. They would be charged back up using the slide recharge, or ebrake.
The problem is that I don't really know how this thing should be put together.
For instance, I don't want the supercaps to be charged by the battery, or maybe they could be but only while pressing a special button, in which case the current should have to be limited, in order for the battery to be able to keep up while not destroying it.
The same problem occurs whenever the regenerative braking switches on, how will the regenerative braking will charge the supercaps instead of the battery? I assume it is easier in this case because the power will simply flow to wherever the resistance is the lowest, ie the supercaps, but I'd like to have a confirmation of this.

Anyway, if someone has information, schematics, suggestions, links or just about anything that could help me to do that, your help would be very much appreciated :)
 
SlowCo said:
Nice build photos.
If you get the chance could you make and post a ride video? That would be cool.

I've recorded a short video of me driving the scooter. It's not great and doesn't really give the impression of speed, mostly because I was single hand driving, had an almost flat rear tyre and it was freezing cold. But anyway, it gives a little idea of how it runs.

[youtube]bhDIf-jayio[/youtube]
 
It is on private.

Dui, I'm building my scooter also, almost finished. I do want to get a new Kelly KLS controller in time. In China are their good websites to purchase wire harnesses, digital dashes and other Ebike parts? I looked in Alibaba but not easy to find!

My scooter here

https://endless-sphere.com/forums/viewtopic.php?f=12&t=59873&start=25
 
SlowCo said:
Unfortunately the video is set as "private" so no-one can see it but you.

It should be all right now, sorry :)

Scottydog said:
It is on private.

Dui, I'm building my scooter also, almost finished. I do want to get a new Kelly KLS controller in time. In China are their good websites to purchase wire harnesses, digital dashes and other Ebike parts? I looked in Alibaba but not easy to find!

My scooter here

https://endless-sphere.com/forums/viewtopic.php?f=12&t=59873&start=25

Hi Scottydog,

Your scooter seems to be nice, good build!
The only problem I see is that the frame seems to be quite heavy, while I prefer to drive light stuffs (better ratio price/performance), but it should be more comfortable and allows you to carry two persons more easily, which is always convenient.

You can purchase anything in China very easily... as long as you live in China! They have an awesome webstite (www.taobao.com), where you can find absolutely everything you want, the only problem for you being that it is entirely chinese and that most of the time they do not deliver outside of China.
Could you tell me the exact reference of the controller you want so I can search for it?

I've checked quickly for KLS controller on taobao and it seems to be quite a new stuff. There are not that much sellers for it yet and they do not provide much description. Seems to me like a risky purchase, but sometimes risk can pay off... When I've purchased my controller there were just a few sellers and it was almost totally unknown too.

The most powerful version for what you asked I've seen is a 12KW version, 72V (KLS7212D). Given the probable weight of your machine, I suggest you to consider this version as the minimum if you want some good performance.
https://item.taobao.com/item.htm?spm=a230r.1.14.31.0kjooh&id=521849821608&ns=1&abbucket=20#detail

You may try to find more powerful stuff if your budget allows you to do so. :)
 
Dui said:
Hi Scottydog,

Your scooter seems to be nice, good build!
The only problem I see is that the frame seems to be quite heavy, while I prefer to drive light stuffs (better ratio price/performance), but it should be more comfortable and allows you to carry two persons more easily, which is always convenient.

You can purchase anything in China very easily... as long as you live in China! They have an awesome webstite (http://www.taobao.com), where you can find absolutely everything you want, the only problem for you being that it is entirely chinese and that most of the time they do not deliver outside of China.
Could you tell me the exact reference of the controller you want so I can search for it?

I've checked quickly for KLS controller on taobao and it seems to be quite a new stuff. There are not that much sellers for it yet and they do not provide much description. Seems to me like a risky purchase, but sometimes risk can pay off... When I've purchased my controller there were just a few sellers and it was almost totally unknown too.

The most powerful version for what you asked I've seen is a 12KW version, 72V (KLS7212D). Given the probable weight of your machine, I suggest you to consider this version as the minimum if you want some good performance.
https://item.taobao.com/item.htm?spm=a230r.1.14.31.0kjooh&id=521849821608&ns=1&abbucket=20#detail

You may try to find more powerful stuff if your budget allows you to do so. :)


Hi Dui,

Cheers for your thoughts. I did want to build a solid bike, but also one that was sporty with good handling. The beam chassis is very stiff, but quite light being aluminum. I did weigh the complete bike, but not sure what I did with the numbers. The cells I am using weigh 102lbs so much heavier than could be as they are LiFePO4. If I could go with 18650 based batteries would half that weight. In kg's I think the weight of the complete bike is 123kgs based on my memory, which makes it lighter than the 125cc version of the scooter. The 50cc version of the scooter which this came from was maybe 105kg's.

Funny think is I looked at my original sketches and it was in January 2008 when I went with the idea to use this bike. So it has been a long time before I went ahead with it! It is the 12kW controller I want to go with, but might go with the older KEB as it'll plug and play into my current harness. The KLS looks to need me cutting and fitting new connectors into the harness and not sure about the key switch setup.

So far in testing I got 37kms on the older set of 3.6 kWh GBS cells I have which used 2.26 kWH. Only confusing bit is it took 2.99 kWh to charge back up which seems like a big difference.

Either way it's either 60 W per km or 80 W per km. I'm going to charge from a different spot with the killawatt meter to see if the voltage loss through the long distance to workshop is affecting the readings?
 
Scottydog said:
Funny think is I looked at my original sketches and it was in January 2008 when I went with the idea to use this bike. So it has been a long time before I went ahead with it! It is the 12kW controller I want to go with, but might go with the older KEB as it'll plug and play into my current harness. The KLS looks to need me cutting and fitting new connectors into the harness and not sure about the key switch setup.

I don't really recommand you the old versions of Kellys. They usually do not include sinewave control, which is a really great feature that, in my opinion, any controller should have.

Sinewave gives you a very precise throttle feeling, its very different from the ON/OFF sensation you get with standard controllers, especially when riding at low speeds. It actually gives a very similar feeling to driving a gas engine, very smooth and very easy to control.
Actually, the best I've tried so far is the one I currently use, ie the sabvoton. I would totally recommand it to you if your machine was a bit lighter, but I believe it will maybe lack a bit of power for your setup. I really hope they'll issue a more powerful version of their awesome stuff :)
For the new Kelly, I think the new one is a sinewave version due to its packaging, but with the information I have so far I cannot be 100% sure. Also, some sinewave controllers are better than others. I tried already a few different ones, they are usually good but there are some disparities. For instance, on the Lingbo controller I tried, the throttle response had a bit of a lag, which was annoying, the regen also had a delay and was a bit too on/off. It was also much noisier than my sabvoton and felt like it was equally powerful, despite it was supposed to deliver 50 more amps.

What I mean is that I m not sure wether or not this new Kelly controller is good. You may want to check for actual reviews from the forum members who already own one, if there is any. The controller is really the key part which will largely define your scooter performance, driving feeling, reliability and personality so you want to make a wise choice here, even if sometimes the cost could seem high.
 
Thanks for sharing.

Those rear gas shocks are nice. Had a Tiger (Taiwan) scooter with similar shocks -- needed a Japanese motorcycle mechanic to set it up properly for my weight, after which the ride was awesome.
 
4LivesPerGallon said:
Thanks for sharing.

Those rear gas shocks are nice. Had a Tiger (Taiwan) scooter with similar shocks -- needed a Japanese motorcycle mechanic to set it up properly for my weight, after which the ride was awesome.

Well... They just look nice actually. They are complete crap in reality.
I didn't knew it when I purchased them but the gas cartridge is fake, purely decorative.

The price was a good indication of its quality anyway, just cost me about 20 USD for a pair so I wasn't expecting too much from them :D
Actually, the fake catridge has been grinded by the plastic part that protects the wheel. You would think that the plastic part would be in bad shape, but no, it's the aluminum of the fake cartridge that has been grinded very deeply by the plastic (about 2 centimeters wide, 4 long and half a centimeter deep). That is a good indicator of how poor the material quality is :D

But they still do the job so I'll probably change them when they will break. It's apparently quite difficult to find those in red, most good quality shocks were anodized orange, and I didn't want to end up with a rainbow colored scooter. :roll:
 
Dui, ni shuo de dui

Nice Scooter, I have a very similar specced scooters. I have just got my Emax 110s upgraded to 60ah large format Calb lifepo4. I was going to use a Sabvoton controller like yours and ES user:Flexy and a few others on here. (there is a spreadsheet somewhere on here for the configuration settings vs motor used).

Instead I am going to finish building my fechter 4.4 bms and then hopefully build a 2.60 lebowski controller. It's great to hear your range values as my commute is 23 miles i.e. 37km. Initially my range will be better but only because I will be limited to 30mph by the original proud eagle controller. I liked how you custom made the mounting box for the batteries, excellent work. Fortunately the emax battery bay is pretty large and so didn't need any mods, Love the water cooling too, very well executed. Have you thought about the ferrofluid from Ebikes.ca for your hub? That will be something I do when I upgrade the controller and use 95v @~26s.

currently I have a two battery system where 10s charge 16s so that I can fit all the 5kw on the bike but still use the old controller. I really need to start a thread for it but so little time to actually finish it. Received all the connectors (db15) and wire I need today to finish the BMS so might have that done this evening.
 
whereswally606 said:
Dui, ni shuo de dui

Nice Scooter, I have a very similar specced scooters. I have just got my Emax 110s upgraded to 60ah large format Calb lifepo4. I was going to use a Sabvoton controller like yours and ES user:Flexy and a few others on here. (there is a spreadsheet somewhere on here for the configuration settings vs motor used).

Instead I am going to finish building my fechter 4.4 bms and then hopefully build a 2.60 lebowski controller. It's great to hear your range values as my commute is 23 miles i.e. 37km. Initially my range will be better but only because I will be limited to 30mph by the original proud eagle controller. I liked how you custom made the mounting box for the batteries, excellent work. Fortunately the emax battery bay is pretty large and so didn't need any mods, Love the water cooling too, very well executed. Have you thought about the ferrofluid from Ebikes.ca for your hub? That will be something I do when I upgrade the controller and use 95v @~26s.

currently I have a two battery system where 10s charge 16s so that I can fit all the 5kw on the bike but still use the old controller. I really need to start a thread for it but so little time to actually finish it. Received all the connectors (db15) and wire I need today to finish the BMS so might have that done this evening.

Hello whereswally606,

Thanks for your nice post !

About the ferrofluid, I've read somewhere on this very forum that someone had issues with this eating the glue of his motors magnets, although, I don't quite wish to use this technique because it both add weight on the rear wheel and internal friction. Moreover, I don't need to ride on very long distances everyday anymore since I've moved to another place closest to my workplace :)

About your controller, if you plan to use your electric scooter as a daily driver, I would really recommend you to find a sabvoton controller, it's a real no brainer, very reliable, smooth and powerful. You can do the Lebowski controller later, this way you can ride your bike first and then decide how to improve it with the Lebowski, which will probably not be easy to do, requiring a lot of time to fine tune and to get reliable. Once it will work you can still sell your Sabvoton or keep is as a spare. Just a thought.

Post some pics of your scooter or, even better, start a topic on what you are doing, I would be interested to follow it :)
If you could explain how to choose a BMS and how it should be installed, it would be awesome !
 
Dui said:
About the ferrofluid, I've read somewhere on this very forum that someone had issues with this eating the glue of his motors magnets, although, I don't quite wish to use this technique because it both add weight on the rear wheel and internal friction. Moreover, I don't need to ride on very long distances everyday anymore since I've moved to another place closest to my workplace :)
I didn't know that about the ferrofluid attacking the glue, but I do have a spare motor as a backup and I think I would still like to try as the tests done by others show real world improvements on heat dissipation. I might also try what ES user, kingfish did in spraying the internals of the hub with rust protecting paint spray.

Dui said:
About your controller, if you plan to use your electric scooter as a daily driver, I would really recommend you to find a sabvoton controller, it's a real no brainer, very reliable, smooth and powerful. You can do the Lebowski controller later, this way you can ride your bike first and then decide how to improve it with the Lebowski, which will probably not be easy to do, requiring a lot of time to fine tune and to get reliable. Once it will work you can still sell your Sabvoton or keep is as a spare. Just a thought.
I have thought about the Sabvoton quite seriously, its not quite plug and play for me since a) I will only be able to realistically use 24s for conservative safety margins and the mcb (master control board) needs modification to run straight off a 12v source as it normally steps the 48v down itself (and that has all the ancillary bits like lights and indicators on it). Its all been done by others before on here so I'm not on virgin territory with it). Flexy & Jonesy have great threads regarding Emax scooters. It would be easier though but not as exciting. my plan is FOC at 100v and just keeping within the 11kw that makes it akin to a 125cc. I will have to go through the MSVA cert here once I upgrade to keep it legal and if I go any higher than 11kw I need a full bike license too which I haven't got yet.

Dui said:
Post some pics of your scooter or, even better, start a topic on what you are doing, I would be interested to follow it :)
If you could explain how to choose a BMS and how it should be installed, it would be awesome !
Will do once I have more stuff to post. I choose the fechter bms as I could buy it local from Zenid in Nottingham UK. It allows expandability and it can do either lipo or lifepo4 depending on which resistors and lvc monitor chips you use. Its all a work in progress but at least its on the road at the moment.
 
Salut Nicolas!! Bon post
 
Just came across your escooter here.. I remember you asking about ultracapacitors...
Looking at the size of your battery and the speed of your take off on that youtube video I couldn't help but form a gutshot view that I don't think even a large ultracapcitor bank could help much, possibly no noticeable gain at all..
As for the 50km/h to 96km/h taking another 5 seconds or so to reach I would say that's due to the design/wind of the electric motor.
 
Better forget about supercaps for now, as they are not commercially available.

I think the Idea is good though. Even regular capacitors store enough energy for a small power burst. Chinese city buses have been running on supercaps for at least 5 years now without known issue. We can say that the technology is mature.

Ultracaps have a potential of storing as much energy as a battery, and charge and discharge 100 time faster. We will definitely see more of that in the future.
The question is will it take a few years or a couple centuries... There was fast electric cars and hybrid cars 100 years ago, but still it is seen as a novelty even nowadays...

I think it is likely that this technology will continue to be suppressed for a while.
 
What diameter is your hub motor on your scooter/moped? Mine is 8” on 10” wheel. I can only run 7kw for 15 minutes before the phase wires are heat to 60 celcius. Im thinking of some 0w oil in there or maybe glue on some ugly heat sinks as a last resort. I can achieve 80kph @67v with flux weakening. Im thinking of trying 80+v and less amps. The acceleration will suffer probably, but maybe I can generate less heat and more top speed? Do you know any chinese controller with variable regen? All I know is the ASI Bac controller line designed in Canada and (from what i’ve heard) made in China and sold for $1600 with control of tune and $1000 with a fixed tune setting. I think the controllers in China for 15kw are $500? Correct me if i am wrong.
 
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