First E-bike build need advice regarding battery

[stantheman]

This is my first Ebike build

I have just bought a: 36V350W 27.5" Electric Bike Freewheel Conversion Kit Rear Hub Motor Wheel Kit

I wanted to know if a 36-volt 15 A battery would be suitable for this Ebike kit.

I am guessing that the 36-volt motor means that I can only use a 36-volt battery.

Somebody told me if I bought a bigger controller I could use 48-volt battery, surely this would burn out the motor.

[73Eldo]

As long as you buy a controller that is either programmed or can be programed for that 36v 350 watts that what it will send out. If you want one that can take in 48v most likely it will have to be the variety you program since it would be a less common application.

[AZguy]

This is my first Ebike build

I have just bought a: 36V350W 27.5" Electric Bike Freewheel Conversion Kit Rear Hub Motor Wheel Kit

I wanted to know if a 36-volt 15 A battery would be suitable for this Ebike kit.

I am guessing that the 36-volt motor means that I can only use a 36-volt battery.

Somebody told me if I bought a bigger controller I could use 48-volt battery, surely this would burn out the motor.

Most 36V motors can be run off 48V battery/controller just fine.. motor speed is in general proportional to the applied voltage (the percentage of the battery voltage the motor is getting applied by the controller)

A 36V rear hub wheel will be meant to go a certain "top speed" if the full 36V is applied.. if the full 48V is applied the motor would go 48V/36V = 4/3 = 1.33x this top speed which may be an unlikely speed but still no worries

If you run at a lower speed than than that top speed it's not really a problem and in general things may be more efficient since the currents will be 3/4 that of the 36V battery meaning less I²R loss in the wiring and controller and also the motor windings

So running at the same speeds (same voltages) with the 48V battery won't only not burn out the motor, it's likely to be better for the controller and battery - no different for the motor since the applied voltages/currents/power are the same..

What really matters is the maximum power that gets applied to the motor and at what speeds... the controllers can generally be set to limit the maximum current/power.. lower speeds tend to be less efficient and generate more heat too...


Regardless, there are a lot of advantages to running a 48V battery instead of a 36V including a wider range of battery options and in general more efficient operation of the motor, battery and wiring...