24v vs 36v hub motor powered by 24v

[RichardT]

Hi friends

A 36V hub motor maybe powered at 24v using a 24v controller. i have tried this configuration before.

But the torque is very weak. If I hold the tire firmly and then throttle it, the wheel will not move even though it can spin well at no load.

I have seen 24v motors on ebikes. Its able to move a person of 80kg.

But why is it when a 36v motor connected to a 24v controller at 24v battery feels so weak? It does not feel like a 24v motor.

So, I am suspecting the reason is the internal resistance of the 36v hub motor is higher than a 24-specific hub motor.

This is why when run at 24v, the 36v motor feels weaker than a 24v hub motor run at same voltage and controller.

Please could you confirm if this understanding is correct?

Thanks.

regards
RichardT

 

[amberwolf]

Differnet winding scheme/etc for differnet voltage motors. Could be another problem instead, but is likely that. You could rewind the motor for lower voltage and tha twould fix it, but it's easier to use the designed voltage and it would work.

Alternately you can put the hub in a smaller wheel (if 26" put in a 20" wheel) and it will increase the torque and decrease the top speed, and might also fix the problem, or help it.


Or put the hub in a middrive instead, and gear it down similarly.

 

[dogman dan]

The winding is likely different, so a 24v design will spin faster on less volts. But also, the 24v controller may need to have more amps. Though the top speed would be less if you use the 36v motor on 24v, you should be able to get some torque by upping the amps.

So the 36v 20 amps controller would be replaced by a 24v 30 amps. or something like that.

Bottom line is, if a decent pull takes 700w, you need 700w when you switch to 24v.