KTM 200 exc goes electric

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j bjork   10 kW

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Location: Linköping, Sweden

Re: KTM 200 exc goes electric

Post by j bjork » Jul 27 2020 3:34pm

I made some changes last week before the ride on the weekend:

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A new bracket for the regen button, now it is held by hose clamps.
It is a little bulkier, but it dosent seem to be a problem.

I also tried my domino throttle instead of a Chinese hall throttle:

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I soldered in resistors on the positive and negative to be able to have some safety from especially a problem on the negative connection. So it wont go full throttle if there is a fault.. I think it is a little more linear, or maybe it is just that I have gotten more used to it.

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I used 330ohm, but higher would maybe have been better.

I also just ordered another charger. You shouldn't drink beer and browse aliexpress or ebay :roll:
Mine hasn't been totally reliable, it sometimes resets and go to a lower voltage. Never higher so far..
I dont really need to charge at 50A anyway, at lest not so far. So I ordered one of those modified 0-120V 0-25A.
I hope it works fine. It seems like they take out one of the big caps to get room for the pots to set V and A, I hope that wont be a problem.. If I want a fast charge I still have the one I built.

thoroughbred   100 W

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Re: KTM 200 exc goes electric

Post by thoroughbred » Jul 31 2020 12:28pm

Hi can you explain how the resistors work to prevent a runaway throttle situation?

j bjork   10 kW

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Re: KTM 200 exc goes electric

Post by j bjork » Jul 31 2020 2:00pm

thoroughbred wrote:
Jul 31 2020 12:28pm
Hi can you explain how the resistors work to prevent a runaway throttle situation?
The domino throttle is a potentiometer, I am not sure what its resistance is but something like 5k ohm.
When you connect ground to one of the base resistor connections (or what it is called in English) and 5v to the other, what you will get on the signal wire (wiper?) is 0 with released throttle and 5v at full throttle.

The problem with this is that if you loose the 5v connection you will get 0v no matter the position of the throttle, not a big problem.
But if you loose the ground connection you will get 5v, and that is full throttle..

What the resistors do is add an offset. Now 0 throttle is maybe 0,3v, and full throttle maybe 4,7v. I cant give a very good explanation in English, but you add resistance to the throttle that you cant access with the output (wiper?) on the potentiometer.

If you loose ground or 5v connection you will still get 0 or 5v from the throttle no matter the position, but now you can setup 0 or 5v as faulty outputs. So the controller goes to protection shut down instead of full throttle.

samv76   1 mW

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Re: KTM 200 exc goes electric

Post by samv76 » Aug 03 2020 4:11pm

j bjork wrote:
Jun 28 2020 11:04am
My charger has been working fine, so I went on and changed controller to the votol em 150sp I bought together with the motor.
The specifications are not very impressing with 380pA and 120bA, but luckily it is unlocked :wink:

I thought it wouldn't deliver good pA, but according to another members measurements it does.
And it sure feels like it does. I have it set up for 500pA and 300bA, just like I had on the nuc.

In sport mode this sure has a lot snappier throttle response, and better power at low rpm.
Just what I needed, the peak power has never been a problem so far :D

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I made the brackets for the nucular 24fet. But when I understood that this controller may be interesting too, I modified them so both should fit. But it is not a very good fit on this controller. I would like to mount it further out, more in line with the seat. But that would mean cutting the old one off, and weld on a new one..
I don't feel like stripping the bike, paint and all that at the moment :(

Some other things to play with:

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An 80 tooth rear and some 11 tooth front sprockets.
The 10 tooth I have now is pretty much worn down, and has a lot of play on the shaft.
I think these will be a tight fit, but were not available in 10 tooth.

I think it would be good to go bigger than 80 tooth rear for the gearing, but it is so damn big :confused:
A problem is that it is steel.. It will probably last forever, but I think it weighs 4kg..
It will need some serious lightening.

The bike worked very good today, but I crashed a few times.
At one time I broke my light switch:

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I used the flasher switch as a 3 speed switch, with reverse, mid (or high, a bit confusing in the program) and sport.

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It felt kind of broken, but stayed in sport so I could continue. I think I will just get rid of it, I don't really need high/low beam atm. anyway. I only use sport on the track, but I like to have reverse.

On the picture is also my button for regen, no variable regen on this controller unfortunately. But it worked pretty good so far anyway. It locks the wheel on loose ground, but I usually did that with the variable regen too. It just skids a little on big rocks, so it seems like I found a decent all-round setting.
What I miss the most from the nuc is the very nice display.'

Oh, and another thing. A guy at the track had a ktm freeride, and he let me test it. I was too tired atm to take it to the track, so I just took a quick spin on a dirt road.
And I can say that my bike sure felt more powerful than it, and definitely snappier :D
It was a bit to short test to say to much for sure, but that was the feeling I got anyway.
what an amazing build!
this post got me curious though.. are you saying that you can unlock a votol 150sp and then set it to 500Pa and 300Ba and it will not burn out?

also very impressive how you can get so much power from a 3000W motor. the parker hannifan on my scooter is 3900 Watts and it already gets hot when configures according to specs. when i increase Pa or Ba it gets waaayyy to hot. sounds like a plan to swap it for one of these motors.

j bjork   10 kW

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Location: Linköping, Sweden

Re: KTM 200 exc goes electric

Post by j bjork » Aug 04 2020 10:12am

Thanks :)

The controller is unlocked, so you can set it how you want.
The phase amps is not very different from the default setting.
It is supposed to be max 380A in these newer controllers, but it seems like they are set up at 470A like the older ones.
So my settings for 500A is not very different.
The default setting is max 120 battery amps though, and something like 140 or 150 in sport mode.
So there are 300 a little more :wink:

j bjork   10 kW

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Location: Linköping, Sweden

Re: KTM 200 exc goes electric

Post by j bjork » Aug 09 2020 12:25pm

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Back from today's ride, before wash.
This time it wasent trouble free though:

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I did plan for problems like this though, so I could bypass the bms and continue.
The display refused to show anything useful, only some Chinese that probably said there is a problem with the bms..
I could look at the app in the phone and at least see the voltages between laps, the charge left didn't show anything useful when the bms couldn't measure the used Ah.

I wasent expecting the bms to die like this though, it seems to work fine for everybody else.
I haven't taken a look at it yet, but I guess there is a blown mosfet. I hope things hasent got too damaged..

j bjork   10 kW

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Re: KTM 200 exc goes electric

Post by j bjork » Aug 10 2020 1:15pm

I took it apart to get a closer look at what is going on.

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It looks ok at first glance, but when I measure the discharge fets are shorted.
It looks like all of them are driven from the same source, with just an individual resistor to each mosfet.
I measured to each mosfet, all of them seems ok :)

When I took a closer look I think I see the broken one:

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The solder on the middle one in the picture seems to have melted.

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Both charge and discharge mosfets are the same.
What I would like to do is unsolder all of them, solder on a 1mm copper plate on the board and use that to get P-.
Then solder back 12 discharge mosfets and maybe 6-10 charge mosfets on the copper plate. Then the charge mosfets will only be for charging, all discharging will only be trough the discharge mosfets.

But I am not sure if I can do that without damaging the mosfets?
Would it work to just hold a hot soldering iron to the metal part of the mosfets that sticks out, and lift off the mosfet with pliers when the solder melts?

ossivirt   10 W

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Re: KTM 200 exc goes electric

Post by ossivirt » Aug 12 2020 1:53am

I have similar looking ant bms that just one time when I installed my battery back after some tire work gave the discharge mosfet abnormality error. I pulled one leg up from every mosfet and found the shorted one. Really strange way to go imo since it didn't faill under any load.. Anyway since I didn't have replacement or hot air station I just left the leg up at that mosfet. Now my 5 replace mosfets have arived and what should be "cheap but ok" hot air station. It has been so nice weather to ride and do other things that I have not tried to replace the mosfet yet tho..

I would not try with just soldering iron to get the mosfets off but maybe it can be done without damage :roll:

j bjork   10 kW

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Re: KTM 200 exc goes electric

Post by j bjork » Aug 12 2020 4:17am

Tanks for the reply, in my case it was the mosfet that i suspected. The one that looked to have been hot.
I have already tried it with just a soldering iron. I will update some results in a not to distant future :wink:

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