Motor perhaps overextended?

E-driver_

1 kW
Joined
May 22, 2022
Messages
356
I have a bike with a 250 watt motor.

I have overvolted this bike quite a lot. So I have a controller with max current of 25. And a 48volt battery 17AH.

When going up a slope earlier today. The motor then started making all kinds of strange noises. At least I am 80% sure this sound comes from the motor.

The battery connections still shows me 48 volts so I don't think the battery or controller have taken any damage. But the motor gave me a lot of strange sounds. It still runs but with a strange sound. Any idea what this is or how I can fix it?
 
If it's a geared hub motor, you probably knackered the gears.
 
Chalo said:
If it's a geared hub motor, you probably knackered the gears.

aha can it be fixed by opening it up? kind of interesting to open and see I guess. So the motor have gears as well? I have never opened a motor. Just controllers and batteries.

The gears are something that can be destroyed by overpowering it or something like that I presume?
 
ebuilder said:
You can do the math. Most motors will do twice the watts they are rated for in 'spurts'
You were pushing almost 5 x's the watts through that motor.

A. you need to describe the sound the motor is making better
B. you have to be prepared to go inside the motor. Probably 80% or more that own an ebike will never go into the motor if it fails.

Best option? Upgrade to a 750w motor if you have a need for 1200 watts.

Yeah man. Probably the motor is caput, right?

But it would be interesting to open it up and see. My whole idea for this bike was actually to create a dual drive with that 250watt motor on the rear wheel. And having a 250 motor also on the front wheel. Making it a 250+250=500 watt motor bike. Perhaps changing the wheel completely, alternatively putting another motor(from another wheel) into my existing 29 wheel, since I like the 29-wheels on this bike. What do you guys think about this?

Is it a big pain in the ass to buy new spokes and installing a hub motor into a wheel that exists but currently have no motor? Would it be wiser to just order the complete wheel perhaps?

Could be a fun project.

But this hub motor in the rear that I have now destroyed perhaps(?). Would be nice to keep using it after a reparation(if that is possible?), because it is very specific to this bike and rear wheel.

I will post the sound tomorrow.

Also now I have a 25amp controller that puts a lot of current into that little motor. And my thinking was that the dual motor is to have two 17amp controllers instead. One going to each motor. But only one battery still. Which should put less stress on this motor if I manage to fix it right?
 
E-driver_ said:
I have a bike with a 250 volt motor.
Are you certain about the "volt"? Or is it some other unit?

(it matters, because a "250volt motor" (one wound to go a certain speed at that voltage) would spin quite slowly with only a 48v battery, only about 1/5 of the speed it was intended to go)

I have overvolted this bike quite a lot. So I have a controller with max current of 25. And a 48volt battery 17AH.
To overvolt it would mean you would be running it at *higher* than the rated voltage. If you are only using a 48v battery on a 250v motor, it is *undervolting* it.

It is important to use the right terminology (and to be as detailed and precise as possible) when troubleshooting a problem so that those helping you can focus on the right things to solve the problem, without sending you down any unecessary testing paths.


When going up a slope earlier today. The motor then started making all kinds of strange noises. At least I am 80% sure this sound comes from the motor.

The battery connections still shows me 48 volts so I don't think the battery or controller have taken any damage. But the motor gave me a lot of strange sounds. It still runs but with a strange sound. Any idea what this is or how I can fix it?

You'd need to record the sound it makes, and post it here, for us to have any idea what they might be caused by.

Providing details of exactly what was done to or with the system, and what happened to the system, leading up to the problem may help us help you find the cause.
 
amberwolf said:
E-driver_ said:
I have a bike with a 250 volt motor.
Are you certain about the "volt"? Or is it some other unit?

I have changed it. Of course I meant to write 250 watt :). Sorry

amberwolf said:
I have overvolted this bike quite a lot. So I have a controller with max current of 25. And a 48volt battery 17AH.

When going up a slope earlier today. The motor then started making all kinds of strange noises. At least I am 80% sure this sound comes from the motor.

The battery connections still shows me 48 volts so I don't think the battery or controller have taken any damage. But the motor gave me a lot of strange sounds. It still runs but with a strange sound. Any idea what this is or how I can fix it?

You'd need to record the sound it makes, and post it here, for us to have any idea what they might be caused by.

Providing details of exactly what was done to or with the system, and what happened to the system, leading up to the problem may help us help you find the cause.

Yeah thanks. Wait a moment. I will record the sound when I get the time today. Thanks
 
ebuilder said:
Each of have a bias on this stuff. What I would do in your situation.
Only one motor and make it the back wheel.
Get something like a Bafang 750w geared hub 'already laced to a wheel size you prefer'.

You will then have the power you need. Why fiddle fart with the complexity of two small powered hub drives? Ebikes aren't really traction limited like an AWD automobile. Most that run dual hub drive systems have two of everything...two batteries, controllers and hub motors. Needless. One is enough as long as it has adequate power.

For the majority of 'regular ebikers' a 750 watt geared hub motor with a 48-52v battery will be fine with top speed of about 30 mph or so. For hotrodders inclined more toward a bit more power and speed like me as only an example, up to 2K watt hub motor and 60-72v battery and 50 amp controller is preferred. To me, that's the ceiling. Above that, buy a motorcycle which runs on 'gas'. High power electric motos suck compared to gas powered motorcycles. No range and power limited if out on the road with cars. I have ridden most of them.

I have one of those bikes from before. I have one with a 1000 watts in the backwheel. And it is very efficient.

But on this particular bike I want to try a dual motor. Not so much for oprimization. But more for the fun of it. And that I want to see if I feel a difference for example riding it in the coming snow for example. Also I go up and down a lot of hills. So I want to see if this makes this old bike more fun and better in those circumstances. Getting more grip in the snow for example.

Thing is this ebike is a really nice bike. A folding bike. Here in Scandinavia you can take folding bikes on the train without paying extra money for it, as long as it is foldable. So that would allow me to go to some really interesting fishing waters as well.

The dual drive is something I have already started skissing on with this bike. I will post a thread in another compartment of this forum I guess, when I have received the two controllers for this build.

Now yesterday I was just restless and impatient. So while waiting on these controllers I decided to try out a 48 volt battery 17AH on the rear racket on that bike. Because I just wanted to "try stuff", since I think that is funny. Also, because I wanted to know if the the motor could take it. I think it could not.

Agree on the motorcycle. But I am getting a bit older so perhaps I will keep riding fast ebikes in nature instead of getting the motorcycle license. And instead get a gas-pickup truck when the time comes and I have the money.

Now since this motor in the rear wheel is probably wrecked now, I guess an alternative path to take could be to completely change that motor, or maybe the entire wheel. And since I want two wheel drive. Perhaps get a 350watt*2=700 watt bike. Or maybe higher. Like 500in the back and 500 in the front.

Do you know if it is a lot of work to install a hub motor into an existing wheel by buying new spokes at the right length? I guess this could be an alternative since I have three motor wheels lying around at home. Only trouble with these is that I will have to take them out of their respecitive wheels and installing them on this bike. Because these motor wheels that I have are not 29-wheels. And I want them to be 29.
 
The sound is a bit weird in the beginning. But the sound of the motor wheel is still as it is in reality.

The soud is in the link here:

https://www.kapwing.com/videos/6342930bf6271c00ca2d7105
 
ebuilder said:
Most that run dual hub drive systems have two of everything...two batteries, controllers and hub motors. Needless. One is enough as long as it has adequate power.
I disagree with ebuilder's comment. Based on my research, most 2WD systems use one battery, two controllers, two hubmotors.

Riding in snow just might be a good application for 2WD. In fact here is a two motor controller:
https://retail.uumotor.com/product/50a-single-controller-to-drive-two-motors/

I don't know if anyone here is running one yet but some have expressed interest. Should simplify things, possibly reduce expense. Maybe you will be the first?

About building your own wheel: Depends on your skill set and patience. Most important is to carefully measure for correct spoke length (not always easy or simple) and use a good spoke length calculator.
 
99t4 said:
ebuilder said:
Most that run dual hub drive systems have two of everything...two batteries, controllers and hub motors. Needless. One is enough as long as it has adequate power.
I disagree with ebuilder's comment. Based on my research, most 2WD systems use one battery, two controllers, two hubmotors.

Riding in snow just might be a good application for 2WD. In fact here is a two motor controller:
https://retail.uumotor.com/product/50a-single-controller-to-drive-two-motors/

I don't know if anyone here is running one yet but some have expressed interest. Should simplify things, possibly reduce expense. Maybe you will be the first?

About building your own wheel: Depends on your skill set and patience. Most important is to carefully measure for correct spoke length (not always easy or simple) and use a good spoke length calculator.

ALMOST did for fun until, $42 shipping. My build with two MAC 10T and two EM3EV 12FET controllers using Barent Hoffmans schematic was a beast. A single battery. Fun for a month then parts went back to two bikes. But it was a fookin fast tractor!
 
The schematic widely used.
 

Attachments

  • WCEC 2WD Wiring Diamgram 8.pdf
    61.1 KB · Views: 22
  • Screen Shot 2022-10-09 at 7.20.53 PM.png
    Screen Shot 2022-10-09 at 7.20.53 PM.png
    29.5 KB · Views: 803
ebuilder said:
I believe your research is wrong. The vast majority of dual hub motor bikes were contrived from a single hub motor bike whereby another motor was added. Almost all have complete redundancy aka a second controller, a second battery, a second twist grip throttle and a second display. This is the most common practice.

https://www.youtube.com/watch?v=SOU4e4SYfug

For a different perspective:

I dunno about the rest of the internet, as I have not researched multiwheel drive systems outside this forum in quite a long time; but in general here on ES 2WD system builders that come here ask about how to run everything from one battery and one throttle (or PAS, etc). What they actually build after asking and being pointed to the various builds like that, I don't know.

I've done it both ways, and found that it is much simpler to use and control when a single control input runs both drive systems, so that is what I use now. There are moments when it would be useful to have independent controls on the trike (separate R and L) but almost always it's easier for me to use just one PAS or throttle to run both of them. (I have thoughts on a switch-in control to independize them for certain situations, I think over in my Nano Tidbits thread, but dunno when I'll ever get around to that...which is how much I need them separate. ;) ).

I've always used a single battery, though, except during certain experiments, simply because the average load on one larger battery is easier on it than the potential higher load a single one might see under some conditions, and because it simplifies the electrical system.

There have been a few independent-battery systems, but many (probably most) of those here on ES use just one to power all the motor systems.

Redundancy is the only really big advantage of independent batteries, so if that's not a system requirement for a particular application, it can be built either way; one bigger battery can see less load on it than each independent one would see, especially if the system is using independent control inputs, and for most situations only one motor is used, so it's peak load on it's separate battery is higher than would be the case if it had one larger battery. (peak load of both motors on separate or unified batteries would be the same either way).

Depending on range needed (for cases where battery size isn't determined by capacity but rather by what it takes to handle a certain current load), it may even be possible to use one larger battery instead of independent batteries, where the larger one is not twice the size of the others, only because the smaller independent batteries are made of cells that cannot quite handle the full peak load of one motor long enough to do what it needs to when running by itself...but the larger battery could, especially if with two simultaneously used motor systems the load is either less or lasts for less time (such as accleration from a stop to cruising speed).


Anyway...there's a number of ways to create multimotor systems, and it depends on the specific application whether each part is better off independent or unified or linked.



(Completely aside from all of the above and not relevant to it, just an info tidbit: old brushed motor systems can do 2WD with two motors but only one controller and one battery and one throttle (or other control input) if it is desired. The motors can be seriesed or paralleled on the output of the controller, depending on the mode of operation desired and the components chosen).
 
99t4 said:
In fact here is a two motor controller:
https://retail.uumotor.com/product/50a-single-controller-to-drive-two-motors/

I don't know if anyone here is running one yet but some have expressed interest. Should simplify things, possibly reduce expense. Maybe you will be the first?

Whoever does get one, I'd love to see inside the case to see if they just have two independent controllers wired for a single control input, or a controller board built with a single MCU that runs two powerstages (like some powerchairs have).
 
AHicks said:
The gears for Bafang motor are pretty cheap and easy to come by. That fact would have me opening up the motor for a look-see.

I think I am going to try this. It looks like the picture below. I guess I should open those screws there below that I have drawn arrows to?
 

Attachments

  • Skärmavbild 2022-10-14 kl. 11.17.40.png
    Skärmavbild 2022-10-14 kl. 11.17.40.png
    1.8 MB · Views: 732
  • Skärmavbild 2022-10-14 kl. 11.17.47.png
    Skärmavbild 2022-10-14 kl. 11.17.47.png
    1.9 MB · Views: 732
I think that I might want to remove a few layers of dirt as my first move. It might help to identify the motor - AND - won't fill the motor interior with dirt when the case is opened up?
 
AHicks said:
I think that I might want to remove a few layers of dirt as my first move. It might help to identify the motor - AND - won't fill the motor interior with dirt when the case is opened up?

Aa do you think it is ok to just hose the outside with water a bit? And then let it dry? It should be able to take some water-hosing right? Or should I do it the gentle well with a sponge or something?
 
Not wanting to have to get it wet if I don't have to, I'd start with a brush of some sort. How stiff determined by what it takes to remove that dirt...
 
Used to know an old man that made a living sharpening chain saw chains. People brought in foulest that had been used to cut who knows what (creosote railroad ties ?). He would drop them in a 5 gallon bucket at the end of his bench to soak a couple of days. Asked what was in the bucket ... he pointed to a bottle "Dawn" dish washing detergent sitting on the shelf.

Some soapy water should not be a problem. Just dry and lube the the pieces parts with the appropriate compound when you are done.
 
E-driver_ said:
It should be able to take some water-hosing right?
Sure. Just like with most parts on a bike, don't aim a high-pressure stream directly at it. You should be fine with an old toothbrush and some detergent (as mentioned above).
 
Okay

I have cleaned it of a bit.

Now what should I look out for when I remove the screws in there later today? I haven't opened an ebike motor before so I am not sure what is what. But I will try to take good pictures.

Hopefully there is some cheap part in there that just needs to be changed or tweaked or something.
 
So I have dabbled a bit with the screws. But realised they sit hard as a mofo.

I think I should they a step back and wait for opinions on good torque wrenches(or other tools for this job?), from you guys, before I keep going.

I think perhaps I will destroy the threads if I screw harder to the left now with my regular hexagon key.

Any idea on how to get this thing open without destroying the threads too much?

I think it perhaps sits with loctite also. Looks like the clip:

https://www.veed.io/view/c34b7652-b621-4e7c-a2a3-60a33c4c1b80?sharingWidget=true

Image of the thing:
 

Attachments

  • Skärmavbild 2022-10-19 kl. 22.03.32.png
    Skärmavbild 2022-10-19 kl. 22.03.32.png
    554.9 KB · Views: 532
Back
Top