Question by solice_in_autumn: WhaCan I use a 48v/600w motor controller for my 36v/500w electric bike motor?t would you like to ask?
Hi, I just wanted some advice from anyone experienced in electric motors please…I just bought an electric bike conversion kit. The kit came from someone who sold it to me without the controller because he said it was faulty, so I have to buy the controller now and I’ve come across a cheap one that has 48 volts, 600 watts….would this be too much for my 36v, 500w motor (if I get a 48v battery)?? I dont want to overload it. Which matters more for compatibility, the watts ot volts?
Thanks for your help!
Answer by dobielustra
The most important thing to consider is what type of motor is in your kit, brushed or brushless. There are hub-motor bike conversion kits in both types. A brushless motor kit will not work with a brush-type controller and vice versa. Most of the bike kits as well as most electric scooters have brushed motors. The brushless kits are the more expensive ones.
About the ratings: Watts are the measure of total power.
To determine Wattage, you multiply the system Voltage by the number of Amps being drawn. (Watts = Volts x Amps)
You can draw the same number of watts from a different voltage by limiting the Amps (current).
36V @ 13.88A = 500W
48V @ 10.41A = 500W
Assuming you have a common brush motor, and the controller is the correct type, you can run your 36v/500w motor at 48v. The result will be that the motor will have a higher top speed than it would have at 36v. You do risk overheating the motor if you run it for too long at full throttle at this higher voltage. But if you take it easy on the throttle, and keep it to about 75% or less for most of the time it should be fine. Even if you give it full throttle occasionally, just make sure you don’t keep it at full throttle for more than about 1 or 2 minutes at a time.
And don’t give it full throttle going up steep or long hills.
That is actually an upgrade that people have done to make 36v e-bikes go faster.
Don’t forget that you will also need to get a new charger if the one that came with your kit is for a 36v pack.
If you already have a good 36v battery pack & charger, the easiest and cheapest way to go would probably be to locate a 36v controller similar to the original one. There are websites that sell scooter and e-bike parts where you can order one.
What do you think? Answer below!