Yamaha YZ250F

[Maico4]

Hello j bjork
I have been sitting around today reading a lot of Blogs, mostly yours. ( I got my second Covid shot yesterday) I read thru your KTM build and now thru your new Yamaha build. Great work. I have done both. My first build was a 2008 KTM. I started it in 2011, and I still have it. EValbum #3817 I am rebuilding it and upping the power by 25%. My controller is a Kelly 72V 500A. I have only been running it at 48V 400A. My battery pack can supply 675A
It has a ME1004 motor and the Kelly Controller, with 48V 45AH Headway LiPo4 cells.
I used a chain and a 19mm jackshaft for the primary reduction. #40 chain is not strong enough. I constantly had to tighten the tensioner. And replace the chain a few times, but there is so much power in these motors, it twisted the 19mm jackshaft.
I am rebuilding it now and a new jackshaft and #530 chain and slotted bearings on the jackshaft. You must have something the can lock the slotted device from moving. The bolts alone will not work.( again too much power)
My new build is a 2008 Yamaha YZ250F. It is on Alta Owners Forum https://altaownersforum.com/threads/a-little-bit-about-my-2008-yz250f-electric-conversion.2055/
The jackshaft in it is the output shaft from a 2008 KTM 450SX as are the gears for the primary drive. there are some pictures of that on the Alta Forum. I am going to use the same idea jackshaft for the upgrade on my KTM Ebike. I had an extension machined on the input end of the shaft too mount the gear. The build is a garage looking build, but now I am going to have a machine shop build it all as a sellable unit. I have probably 50 hrs on it so far and all is well, except the controller. I have a Kelly 72V 700A controller (input supposedly), but it doesn't put out the power it claims. I have watched the current on my current meters, and I have 3 battery packs, each one putting out about 200A. ( I can connect and disconnect each of the packs.) They all do 200A alone, but 270A any 2 or all 3.) And I lose terribly to my friend's ALTA, in a drag race. My batteries are the same as the Alta VTC6 140 per pack 420 total. They claim to carry 30A each cell, 7P per pack give me 210A per pack, and actual is right around 200A on my meter.
Anyway keep posting , the world is watching. Great work. My Username on the Alta forum is DonCox

 

[j bjork]

Thanks for the reply, always nice to know that people are interested :thumb:
I looked at your build and realized that I have seen it before sometime.
To bad I can only see the small pictures, so it is difficult to really see anything.
So with this motor you can easily split stators to run dual controllers?

My build is on a hold now, waiting for news on the motor.
I can make all the brackets, jackshaft etc., but I want to be sure that I really are getting the motor..
Good, powerful controllers seem to be few and far between (and big and expensive), especially if you want to go over about 90V.

 

[j bjork]

I made an expensive decision and bought this:

It is a 2020 passat gte battery that has run 640km, should have done about 10 charge cycles I guess.
I could be waiting a very long time before I got enough modules otherwise, at least the new version.

I started taking it apart a little:

I sure am eager to continue, but I am going to wait and get the right tools and protective gloves.
It is after all 380V in it at the moment, nothing to play with :wink:

 

[larsb]

How much was it? Been looking too!

 

[j bjork]

I got it for a pretty reasonable 25.000sek.
They usually want more than double from what I have seen.
This was registered with "hybrid error", probably because of damage to the front of the car.
But I guess they couldn't see if the battery was ok.
I did a diagnose of it, and it didnt register any relevant fault codes. Only a few because it wasent connected to the car.
And all cell voltages was fine, that was enough for me :wink:

 

[MikeSnow]

Whats the specification on the battery, kwh?

 

[j bjork]

It is 13kwh in total.
Each module is 1630wh.

 

[j bjork]

High voltage gloves and tools.

Without cooling pipes, bms box with contactors etc.

It was nice to have the right lifting tool.
The orange series connection in the middle would have been difficult to remove otherwise.
I guess it would have been possible to lift both modules a little and be able to remove the connection, after that lift one double module at a time.

I plan to use those series connections between the modules, but flip the cooling plate so the connections face the other direction.

 

[HrKlev]

Looking nice! Are these the same kind that you used on the other bike, just a newer version? Do you know the weight, or even more interesting kwh/kg and kw/kg?

 

[j bjork]

They are the same size, but not really just a newer version.
On the other bike I have panasonic modules from a golf.

These are a newer version of samsung modules for a passat.
There are an older version of samsung cells for passat that are 28Ah, these are 37Ah.

But I read somewhere that these cells are used in the new golf as well (2021-?)
So in a way they are a newer verson of golf cells too I suppose.

I think I have posted some numbers, but I dont remember now. What I found out was that they were a little heavier then the older passat cells, but with lower Ir. The Ir might be just because they are newer as far as I know.

 

[j bjork]

Splitting a module to 6s:

So, it is all welded together. I have to cut it open.
First i planned to cut the side plate just next to the weld, but it is very close to the cell.
I realized that the right way to do it is cutting the end plate right next to the side plate.
The only thing that will happen when i go trough is I will scar the tube where the modules are bolted together a little, and that dosent really matter.

Like this. I just made the cut quick, then cooled it all off with compressed air. I dont think it heated the cells at all.

So then it looked like this. The cells appeared to be stuck together with double sided tape or something.
But they actually split apart relatively easy with a little persuasion from a plastic wedge.

The most interesting part was to saw apart the plastic over the cells without cutting in to the cells though.

This is how it looks now.

 

[j bjork]

I have started trying to fit the battery to the bike.
How come things always seem to grow when you actually try to make them fit

Hard to tell on the picture, but they are pretty high..

Time to cut up the tank to see where I am with everything:

Cut a little, then a little more.

When the batteries are standing on the motor they are still a little higher than the tank.
The tank should be 5-10mm lower, and that is without any housing over the batteries..

Then there is the 6s module.
There was some extra mm between the rear part of the tank and the seat.
I needed those mm, so the top of the tank had to go.

I couldn't get the cells between the rear chock and the seat, but that space is needed for contactors and fuses anyway.

 

[larsb]

Splitting a module to 6s:

Nice work! :thumb:

 

[j bjork]

Thanks
It is not finished yet, but I think it will work out.
I need to get end plates made, I am trying to decide how thick they need to be.

I wonder if 10mm alu would be enough, I think that would be pretty stiff?

As everyone can see, there hasent been much done on the bike.
Still waiting on the motor, but now I have been told it should be ready next week.
So now I can only hope that it will be

I have spent a lot of time trying to decide on a controller or controllers.
I dont have the patience to finish the bike and wait for the right controller to show up.

There is the APT 96800 that qs recommends. It seems to be a bit limited in performance, but would probably be enough the first season.
A big problem is the size. I dont know where to put it. And I dont want to make big changes to the bike to fit something I dont intend to keep.
Compared to other options it is relatively cheap. It is 650$ if I remember correctly. But then there is shipping and import fees, so it will likely end up around 1000$ That is not that cheap anymore, at least for a controller to use a limited time.

I have been looking at this too:

The Emsiso emdrive 150_300/120. It looks interesting, and I should be able to fit two of those.
I dont really know how to compare rms to peak values, but they should be a lot higher.

Maybe I have seen rms*1,4= peak? It probably isn't that easy.
Anyway, I think 300Arms (x2 for 2 controllers) is pretty good.

But there is something else that I dont see how it can add up.
It is max 120V, and max 200A dc input. And I am pretty sure it said in the manual it should have a 200A fuse.
But it can take 43kw for one minute? That is more like 400A..

I asked Emsiso about it, guess what? No answer..

I have also asked them about a em400 that I found used earlier, no answer

frock em, moving on.
I found a decent deal an a big box of anxiety and grief:

I hesitated, mainly because I think I have enough problems. I dont know how to fit it on the bike, but I dont think that is the biggest problem :wink:

I slept on it, then I pushed the button. That led to that they had time to go on vacation, so it will take an extra week before I get it.
I wonder if anyone is interested in my long rant about controller anxiety, but here it is for the interested to read :?

 

[Elektrosherpa]

I have started trying to fit the battery to the bike.
...
I couldn't get the cells between the rear chock and the seat, but that space is needed for contactors and fuses anyway.

That's one of the advantages of the good old "twinshock" construction which I am going to use -
much more space available under seat and tank...

 

[thoroughbred]

im very interested in the controller situation. good for you to jump into the sevcon morass. how much were the emdrive controllers you had considered?

 

[jhoexp]

I slept on it, then I pushed the button. That led to that they had time to go on vacation, so it will take an extra week before I get it.
I wonder if anyone is interested in my long rant about controller anxiety, but here it is for the interested to read :?

I can relate! I went for a sevcon gen4 size4, and it's already creating problems for the fitting. It's big and heavy and had to cut some of my rear sub-frame brackets to make room for it.

The size 6 seems really hard to fit on a small dirt bike, and is sure overkill. Zero/Brammo use it on much bigger motors and they are pushing 40+ kW...

Did you bought it from kit elec shop in france? I did the same with mine, but found a used ixxat much cheaper on ebay.

What cable size where you planning to use for the battery? Will 50mm2 be enough?

 

[j bjork]

I havent seen any price for the emdrive 150, and they didnt answer so I dont know.

The size 6 seems really hard to fit on a small dirt bike, and is sure overkill. Zero/Brammo use it on much bigger motors and they are pushing 40+ kW...

Did you bought it from kit elec shop in france? I did the same with mine, but found a used ixxat much cheaper on ebay.

What cable size where you planning to use for the battery? Will 50mm2 be enough?

I think the motor are about the same size? The zero motor can probably handle more though.
I also plan to push 40+ kW :wink:

Yes, it is from the same shop. I didnt want to take any chances, so I ordered everything from them. I thought it would be easier to get support if there is a problem that way.

I havent really decided on wiring, but I dont think I will go crazy big. I dont think it will be necessary for the power handling at least, my average will not be very high. It will only be short bursts of high power.

 

[jhoexp]

I think the motor are about the same size? The zero motor can probably handle more though.
I also plan to push 40+ kW :wink:

Oh, sorry, I forgot you are going with the misterious QS180, I was thinking about the 138!
Sure this setup should be easy capable ok 40+ kW peak and probably 20 kW continous, or more.
Latest Zero SR/F-S can pull 80 kW (and they still have a revised version of the size6, for what I understand), so there sure will be plenty of current...
Do you know how heavy the QS180 is? Do you intend to mount the Sevcon on the rear subframe or somewhere else?

Yes, it is from the same shop. I didnt want to take any chances, so I ordered everything from them. I thought it would be easier to get support if there is a problem that way.

The guy behind the shop has sure great experience with them, and seems friendly and helpful. Very positive experience with the shop (great communication, etc...), it was a pleasure to deal with professionals like them for once, instead of some sketcky chinese sales department. :wink:

I havent really decided on wiring, but I dont think I will go crazy big. I dont think it will be necessary for the power handling at least, my average will not be very high. It will only be short bursts of high power.

I remember you talking about this in one of your build threads, have to go back and find the post. I went for 50mm2 battery wire also considering that the smaller qs138 has 35mm2 (I think).

 

[j bjork]

Do you know how heavy the QS180 is? Do you intend to mount the Sevcon on the rear subframe or somewhere else?


The guy behind the shop has sure great experience with them, and seems friendly and helpful. Very positive experience with the shop (great communication, etc...), it was a pleasure to deal with professionals like them for once, instead of some sketcky chinese sales department. :wink:

I dont remember if I have seen a weight number, maybe..
I am not sure where to put it, but I think the only way will probably be the right side of the rear subframe.

Yes, it has been a pleasant surprise so far. I didnt expect to hear from them for a week, but I got a few mails during the weekend and it seems like the controller should ship out today

 

[j bjork]

I just got a mail from qs, with this picture:

Finally it is happening, it is finished

I have been wondering how to compare controllers that specify output in Arms and those that specify A (peak).
Finally I found an easy formula, Arms= A x 0,707
So the 2min 550Arms on the size 6 = 778A
And the boost 660Arms = 933,5A

Not bad
A link:

https://download.tek.com/document/55W_28941_0_MR_Letter.pdf

 

[j bjork]

Wtf, it looks like they have mounted it wrong

It looks like the middle section should have been the other way around.
The cooling fins looks like they are in the way of the mounting bolts.
But on the other side of where it is mounted together there is a flat surface that I suppose should have been where the mounting holes are :?

 

[j bjork]

This is what I mean:

The middle section should have been flipped 180 degrees.
To fix this the motor would have to be rewound.
Is this for real?!

 

[Elektrosherpa]

Maybe they think you should use bolts which are so short that they do not come out of the threaded holes ?

 

[j bjork]

On the drawing I got they are not threaded.
They are 10,5mm holes, and they line up as it is meant to use long bolts from one side to the other.
Without that there are only 4 m6 screws holding the motor together.