Swedish Kona DH Cromotor 10kW Kelly *Water cooling?*

The cap is actually okey. When measured for resistance it seems as if the multimeter charges it, and then it reads infinite.

I´m not actually quit sure what you mean about the rest... Hi/lo? Forward bias?

I should have taken electronics in school and not mechanics :cry:

But then again, then the rear wheel might have come loose instead :D

The new FETs are on their way at least, hopefully might get them on friday with a bit of luck.

I have also gotten a good answear from Lyen with some stuff to try. He thought the hall angles might be a bit off or something of that nature.

It´s bed time now, but will look at this more tomorrow...
I've blown up 2, 18fet controllers multiple times.

I'm giving up on the infinion? based controllers. Time to drop some money on a nice Kelly controller.
I hear what your are saying binlagin...

There will of course be a breaking point where I might as well could have bought a more rugged controller, like the Kelly or??? (what more is there?)

But for this season, I think I will try to keep the Lyen 24FET alive.

I´m still not sure what actually happened... The connection of the second sets of halls naturally seem as the culprit, as I rode some 100km with the first set, and then only 1km after hooking up the second.

But if the halls got such a bad reading that they fried one phase, wouldn´t the motor have run very bad and with even more, constant twitching than it did?
It actually ran real smooth, apart from the one twitching incident.

I guess I will replace all the FETs on phase 1, even the ones that looks okey, and go back to the first sets of halls and just see what happens.
According to the postal tracking service, I should have my new 4110 FETs this afternoon.

I have started to replace the wood panels on my house, so if the rain holds off I might need to work on that this evening.


But hopefully it will rain so I can spend some quality time with my Weller down in the basement, replacing the FETs :mrgreen: '

I have also been in contact with Fany on Kelly controllers. As I noticed that their 72V controllers can handle up to 90V battery voltage, I made an inquiry about this, and she confirmed that as long as I keep under 88V hot off the charger, it would be fine.

I was looking at this controller at first, 499$, http://kellycontroller.com/kbl72301x24-72v300abldc-controllerwith-regen-p-263.html

But then I saw that they have what they call "Bicycle controllers", and this one fell to my liking for 480$ :twisted:


It doesn´t have regen, but I don´t think I will be needing it anyway. For 60$ extra I can have regen but...

It´s a bit misleading that the rate the controllers by phase current and not battery current, not that it matters, but would be easier for comparison.
if you take a KBL same range you can have the 120V limit and to calculate battery AMp you can read the FAQ :
"How to calculate motor current and battery current?

The controller current rating is the motor current. Basically motor current=max motor current *percentage, battery current=motor current*percentage.
For example, KEB72450, we set Max Motor Current and Max Battery Current to 80% and 60% respectively. The motor current will be 150A*80%=120A peak. The battery current will be 120A*60%=72A."
depending your motor you can ask for the J2 cable you need (crystalyte) , you will need an external shunt for the CA and a main coil contactor could be an option...
Thanks for the note on the shunt for the CA, it hadn´t crossed my mind actually...

All other features in the CA v3 should work regardsless of the controller right? Like power throttle, temperature protection, cruise control and so on? All it does is to modify the outgoing throttle signal that goes in to the controller?

I would very much like to keep under the 500$ line for this controller.

Even buying an other controller is streching it right now, the house will need some 10 000$ this summer, give or take...

But at the same time I don´t want to get stranded if I cant get the Lyen 24FET to work.

I have done some serious thinking this weekend regarding max voltage and battery configuration.

My setup at the moment is 20S Lipo (84V max) and a 26" wheel. This gives me almost 70km/h fully charged with 4500W. Plenty fast in other words...

What I might wish for in the future is more torque, going fast on the road is fun for a while, but ripping through the woods and up steep hills is more my game.

More torque can be achieved with either more current, or a smaller wheel.
As more current will stress pretty much everything, I think I will go with a smaller wheel when that day comes, like 24" or so.

The difference in circumference is something like 8-10%, so I will still be going over 60km/h.

And, the smaller diameter might and higher torque might allow the motors RPM to go up more, so I might not even see a difference in speed at all.
you really should test all of the mosfets before installing just those that smoked. if you put it all back together and did not find the bad ones then you have to take it apart again.
Before I read what dnmun wrote, I replaced the 8 FETs on the phase that was fried.

And it´s still dead as a duck...

I´m not sure how I test the rest of the FETs to see that they are ok.
All I have is a Fluke multimeter to test with.

But I did order 25 new FETs, so the easy way would just be to replace all of them.

The CA fires up, and I can see the voltage on the throttle out change as I twist it, so at least the 5V from the controller works right?
you test them with the diode meter on your voltmeter. you can measure the body diode in each set of mosfets and compare them. if some are way off then they are likely burned. if they are shorted they show up as a short. measure the body diode from the source to the drain, and it should be a diode, open circuit when reversed drain to source.
I found a video on Youtube showing how to measure FETs with a multimeter and I measured the 4 ones on the same phase as the 4 that fried. They were all fine...

To measure the rest of them in the controller, I must solder them off right?

I measured between the ground and 5V down to the halls, and got some funny values. 1,7V between gnd and 5V+, and constantly 2,2V between the halls and gnd. Nothing happened when I turned the wheel.

Thought I was on to something here, so I connected up the other set of halls, and got correct values. 4,99V on the 5V, and 0V or 5V between the halls and gnd.

Of course this was the problem, or at least so I thought.

I carefully twisted the throttle, and the wheel started to turn. After like 5cm there was fireworks coming out of the controller.

Same phase, same 4 FETs, but bigger bang this time :)

However, the thought of there beeing something wrong with the motor does come to mind...

I measures the phase wires, and nothing funny there, hovering around 1ohm of resistance in each winding. Certainly no short at least...

I´m kind of giving this up now and ordering a Kelly.
i have never seen a utube video on how to test them. i just test them right where they are. in fact you don't even have to open the controller to test them since both sides of the mosfets are available at the phase wires and the red and black power leads to the mosfets.

can you list the forward voltage for each of them and for the new mosfets too?

none of them were shorted? i assume the old ones you took out were all dead, shorted?

That seemed to work, I got the same kind of reactions that he did.

I will look more into this tomorrow, it´s getting late here now, and I got kind of bummed out when it blew up again.
Couldn´t keep out of the basement...

After clean up, I noticed that all the FETs on the first phase were blown this time.

Also, the large caps looks burned, but not swollen on the top as they usually are...

A smaller transistor(???) marked Q2C is also a gonner...




As I said before, I will order a Kelly controller, but it would be a nice learning experience to be able to fix this sucker up as well.
But it feels like that even if I replace the FETs again, and the damaged caps and everything else, it will just blow up again, leaving me none the smarter...

Are there schematics or something on these things so I at least can learn something of the cost of blowing things up? :mrgreen:
were the capacitors shorted? i think the one next to the mosfets just got torched. it may be ok.

if you can list the forward bias on the mosfets we can guess if they are working right. and compare it to the replacement mosfets you have.
I will take another stab at this tonight when I get home.

However, I don´t think I have the knowlegde to solve this mystery, so I orderd a Kelly controller just now, http://kellycontroller.com/keb7210124v-72v450a10kw-bike-brushless-controller-regen-p-1183.html

What I need to do before connecting it up is to measure that the motor is okey.
The one set of halls gave really strange values, even tough it is the one that has worked for 100km.

I will borrow an old analog oscilloscope from work and try to hook it up to the halls and see that they give out correct values and most important, dont skip a cycle when going past my damaged magnets.

Does anyone know where to get replacement hall sensors for the Cromotor?
Peter Sternersson said:
All other features in the CA v3 should work regardsless of the controller right? Like power throttle, temperature protection, cruise control and so on? All it does is to modify the outgoing throttle signal that goes in to the controller?
the kelly have temp protection, torque , speed or mixed mode...so yes it just cheat the controller...

I did not test it yet, waiting the dropouts, motor is running, the inconvenient is that you have to use the cable to change the controller if you're using the CA just to read infos...

here is mine: http://kellycontroller.com/keb72601x24v-72v280a6kw-bike-brushless-controller-regen-p-279.html

Doc said to me that I never had trouble with them and the major adavanteg is the regen modes...if you burn it they repair it under warranty, I hope I'll be able to tell you soon (coples weeks) , I plan to put 120Amp , controlling the temp , steps by steps, with a HS4065 and 24"
Hi Guys,

I bought this controller for my Cromotor V2 with 24" rim and I'm really happy with it:


But be aware about the 10 sec max amps ratings for the controllers I have seen here, seems a bit to low to power a Cromotor or a 54xxx in my mind...even if the 10 second rating seems very high.

Good day!
Black Arrow
pchen92 said:
I'm more interested in this version http://kellycontroller.com/keb7210124v-72v450a10kw-bike-brushless-controller-regen-p-1183.html
80 km/h is too much for me. 70 is amply enough for me !


Don't use your 24S batterie pack with this one the maximum Voltage rating is 90 Volt. And your batteries packs is88.8 Volt nominal and about 100.8 Volt of the
charger. :wink:

Good day!
Black Arrow
Fany at Kelly told me that the 72V controllers, with 90V max battery voltage, were safe to use up to 88V hot of the charger.

So if you charge your 21S to 4,15V or something you should be fine.

My controller is at the Fedex facility now :D

I did some measurements yesterday trying to determine if the halls in the motor were ok.


What you see are 2 halls connected and the wheel turned to a position so both halls gave 5V out.
I´m getting some interference, probably from the 50Hz in the outlet.
My plan was to get a high or low line on each hall, and then spin the wheel at a constant speed, thereby producing a square wave. This way, I could clearly see if there was any disturbance when the halls go past the damaged magnets.
Now I just have to come up with a way to get rid of the disturbance...
there's no disturbance, you should see clean square signals. Mabe a ground wire is broken somewhere (One of my probes
has a dodgy ground wire and shows 50Hz from the net, can be fixed with a wiggle :D )
Will I really see a square signal when the wheel is standing still?

I haven´t set the wheel in motion on the picture.

I seem to remember I got the same kind of wave then I hooked the oscilloscope directly to the 5V PSU. So there must be some sort of disturbance...
instead of going to kelly why not try that sine wave controller from greentime. it has the 4110 mosfets and can go to 5kW and it even looks like the kelly.

i just cannot figure out what the price is. alibaba is saying $1300 but i think it means 1300 yuan which is only $200. seems like the most interesting controller out there to try.

now it is saying 1380 yuan, i think exchange is 6.58 yuan/dollar.