Electric Scooter restoration, and build.

[evigh]

Hi guys. I am currently restoring an electric scooter from scraps. I bought it cheap and I will build and fix all the components myself.

It's a Electric EU scooter moped. It was bought from gobyel.se here in Sweden.
It was build by Cemoto, a Chinese company that sells electric scooters. During my research I have found that almost all electric scooters, and gas scooter that come from China, uses the same frame. Slightly different between gas and electric. But most electric scooters look the same underneath.

It was originally a 3000W 48v scooter with 60Ah battery. Disc brakes and everything. What I got was the frame, the old battery ( half dead). And the motor.
I am fixing the rust, repainting the frame. And building my own battery on LiFePo4 cells. Its gonna be 76 volts 60Ah.

Controller will be a sabvoton 100 Amp controller. Programmable.

I have a build blog that I update weekly. So if anyone is interested head over to www.eternal-power.se

Do you think I should post build info and pictures here to?

 

[jonescg]

Always worth posting here I have my build log across three forums, but spend most of my time on ES.

 

[John in CR]

If that 100A controller is the phase amp rating, then it's not nearly enough controller. If the rating is a continuous battery current rating, then it should be up to the task.

 

[evigh]

If that 100A controller is the phase amp rating, then it's not nearly enough controller. If the rating is a continuous battery current rating, then it should be up to the task.

The controller is rated at 100 Amps current, and 260 phase amps. I guess I can tweak it to around 300 phase amps.. It's a sabvoton 72100 controller.

Do any of you know how to unlock it, or change the firmware to get more amps through it?

 

[evigh]

I will post the build blog so far, and later Ill write on the blog and also here.

The build so far.

After much searching I finally got hold of a frame of an electric moped (Scooter). That was also registered as an electric EU moped class 1. (45 km/h).

I found a company that sells electric mopeds (scooters)

http://www.gobyel.se. I contacted them and asked if they had any used, broken or frame laying around. Fortunately they had.
It appears that the owner of the company bought this moped as a first test to learn on. It was in traffic for a while down in Gothenburg.
But as this is a Chinese build, they sometimes forget to build it for harsh environments.
Like the salty Sea-air on the West Coast.



Electric moped first view
View attachment 3


Despite the first picture I got on the moped, and friends advising me against taking on such a huge project, I still bought it.

What I got was the following:

A rust-eaten chrome peeling, blackish frame. Without any plastic, except for the front wheel cover. With brakes and some cables.



I half dead 48V battery.
A 10″ 3000 Watt 48V hub motor with tire.
A 48V Li-Po charger.

As soon as I got it, the first thing I did was examine the state of the battery.
It was a 48V 60Ah Li-Po/Li-Ion pouches of unknown quality. 13 groups of 8 cells each á 7400 mAh.
1 group was completely dead and leaking. 2 group had some cells that was leaking and dead. The rest looked OK.

I cut open the battery package and rewired and soldered 8 of the groups to a 4S2P battery, 14.4V 120Ah battery to use with my solar panels. It seems to charge and hold its charge good enough to power my garden lights. Later I will use it to charge my Scooter through a 72v MPPS.





Next step is to strip the frame completely, fix the rust and paint it.

 

[evigh]

Part Two. Stripping it down.

The moped is in my garage, now its time to strip it down and fix the rust.


It looks naked without the wires, well it didn´t have much clothes to begin with.
As I have to remove all rust, it has to be completely stripped. One thing I have learned over the years is to store and label all parts as you remove them. So all parts was put into separate bags and all wires was labeled as they where removed.


Next steps was to sand and brush all the lose rust away, and paint it with rust eater.
After that was done and had dried for 24 hours, it was time to start painting.
I went with Hammerite Metal Paint on a spray can. As I noticed later, using a spray can with a silicone based paint, is not a good idea in a small room without ventilation. It sticks to everything and everything is sticky. And it smells paint in the entire house.
And I also noticed that I had paint everywhere, including my nostrils.


But the result was pretty ok.I only painted the subframe, and stands with spray. Next step is to paint the rest of the frame, with a paintbrush.

 

[evigh]

Battery Build

Time for a battery post.
I though long and hard on what type of battery I should use for this setup. In the first version of my electric moped I used 18650 li-ion cells. I even bought a battery spot-welder.


At first I used 80 Samsung 26F 18650 cells in a 20S4P configuration. Later I added another row, total 100 cells. This was only to extend the range enough so I wouldn’t have to push it the last 800 meters if I forgot to charge at work.





I didn’t chose li-ion cells this time. As they can be somewhat unstable, and I want to pull a lot of current from them. Just image google li-ion fire and you’ll understand. I don’t want a possible fireworks show between my legs.

So I bought 48 of these.
30Ah LiFePo4 Prismatic cells. They are rated at 3C continuous output and 9C peak. And as I will use them in a 24S2P configuration, I can pull 180 Amps continuous and 540 Amps peak.
View attachment 1

My controller that I will start with is rated at 100Amps continuous, but I probably want to upgrade later. The motor is only a 48v 3000w hub motor, time will tell if I have to oil cool this one too.

I will use a BMS, but only for charging and cell balancing. Because it is way to expensive to buy a BMS that has over 300 Amps throughput. But I still want monitoring on each cell, so I will use 3 of these.


They will monitor each cell and if one cell drops to low it has an alarm function. I will also install a 74V battery indicator, that will show the state of the charge.

The only question now is, how will I fit these into the frame.

 

[evigh]

I have learned a lot in the last few days. Mostly how NOT to build a battery pack.

These are the tools you should not use to build a battery.

View attachment 2
A hole-punch for paper is not a good idea. It worked for one of the tabs, but if I wanted to punch holes in more than one at a time, and get them aligned, it was not good. It’s for paper..

Same goes for the leather hole-punch.

Drilling works pretty good, but the holes get all messed up, and the risk for puncture and other damages is high. And the metal filings from drilling is sharp, and could get into where it should not be.

Using a riveting gun and rivets to connect the tabs works OK, but if I want to disconnect it I have to drill the rivet out. Risking damages to the battery.

So what do work?

This is my new best friend.
It’s a hole-punch for metal work. With adjustable hole depth. With this I can punch right trough all 4 tabs at once. And it leaves a perfectly round beautifully edged 5mm hole.

Perfect for a M5 bolt, washers and a lock nut. Also adding a balancing wire for the BMS and Battery voltage meters.


This is my first 10S2P battery, 32 Volts and 60Ah. I have to build one more like this and one 4S2P cell. Then I have to build a custom battery box. Maybe then I can use my riveting gun..

 

[evigh]

Just ordered a batch of ferrofluid from grin tech. That I'll try, and of course post my findings.

Currently I am running my daily driver, 300W scooter, tuned to 1800W continuous, with ATF oil cooling. And there is a dramatic difference in cooling.

 

[evigh]

Updated build.. Been a while since writing and building. Have been in the garage the last 2 nights and fixing the electronics. Replacing wires, measuring what they do and where they go. Soldering, crimping and isolation.

I have fitted a 72v to 12v DC to DC converter. A new Led light bar, 40 Watt as main light. My old car horn from my Volvo V70. Also a custom speedo, with hall sensor for speed, battery monitor, etc.

Pictures will come in next update. Tonight I will take it for its first spin in several years.

Question, those of you that have a sabvoton controller, what settings are you using for Ebrake, variable regen, and throttle control.