Replacing a 36V (250W) geared motor with a 24V one

[maro]

Hello, I have a GoldenMotor kit, LIFEPO4 battery, 36VDC with 250W motor (PRO902). I love it, the only problem is that the max speed is about 24-26Km /H.
I can do this much with my road bike.

Would be a problem to buy a 24VDC motor and use it with the 36VDC battery / controller to get more speed. GoldenMotor have two versions of PRO902: 24VDC and 36VDC.
This would be the cheapest option as the battery is veeery expensive. I live on flats, hills not a problem (But very windy).
Any advise would be appreciated.
Thanks.

 

[amberwolf]

It depends--if you run a 24v on 36v, at the same current limit, the wattage (and waste heat inside the motor) will be half-again what it would've been at 24v. So it will heat up faster. As long as cooling exceeds heating, that's ok. But if it doesn't, the motor can meltdown.

Keep in mind some motors are the same winding for both voltages, so it just runs slower at the lwoer voltage, which means for your purposes the motors would be identical. To do what you want, the lower votlage motor has to be a different winding that is the same speed at it's voltage as the higher voltage motor is at it's voltage.


You can also chnage speeds by changing the gearing...which in the case of a hubmotor will be the wheel size. Bigger wheel is faster speed for same conditons otherwise--as long as there is sufficent power to overcome air resistance/etc at the higher speed.


Keep in mind your controller and battery may not be able to supply that power, at least not without prematurely aging them (and also reducing your range), so you might end up changing those anyway to get what you want. Probably not, but it happens.


Another potential issue is some contorllers have a speed limit built in, often around 25km/h, to make them legal in various places. If that's true of yours, it doesn't matter what motor/etc you use, you'd never go any faster.

 

[fitek]

Yeh you can get a different wind in a motor. I have two 36v hub motors... one for 20" wheels and one for big 700cc wheels. But I only have 20" ebikes. I never used the one for 700cc wheels in a 700cc wheel, I just wanted something that spun slower in a 20" rim.

 

[maro]

Hello,
I have a 36V (250W) Goldenmotor Kit on bike that I love, except the max speed (15-16MPH).
My idea is to purchase just a 24VDC motor, ad they are the same size. And replace only the coil side of the motor, with the wires, leaving the magnet side with the wheel intact. This way will be more simple and cheaper than purchasing the whole wheel, etc.
I will have a hot rodded 24VDc motor at 36 VDC, that means more speed.

Will this work? or I have to change the whole wheel?
I would like to stay at 36V as I have a very good FIFEPO4 battery.

Thanks for advice.