Can an electric motor take different voltages?

Question

I am interested in buying an electric bike that has 2 batteries that opperate at 12v @ 10 amp hours. They are designed to work together to deliver 24v to a 450 watt (peak) motor at the front wheel. Unfortunately these are heavy SLA batteries, and I would like to replace them with state of the art Nanophosphate Litihium Ion batteries.

Now the kicker: I can only find 36v versions for use in DeWalt power tools (though they are very energy dense).

So what I am wondering is if I can buy 2 / 4 of these and wire them to deliver no more than 36v continuous to the 24v motor and will it improve performance or just burn up the components.

Also as an added question, if it is not possible to run 36 volts directly is there a controller that could accomplish this.

Thanks!

The motor is from Currie Technologies, specialists in electric bikes.

I should add that the motor is DC as will be the current delivered to it.

Answer 1

Just replacing the 24V pair of batteries with a 36V group will very likely cause something to fail. It is possible that a controller could be designed to allow a 36V group of batteries to work with the motor, but it isn't something that you are likely to be able to easily find and mate up to the existing motor.

Additional information:
If you get a 36V PWM controller and set the current limit to the maximum continuous rating of the motor, that might keep you out of trouble. If the motor has a higher short-time current rating that you want to utilize, that might be difficult to set up.

Look at: http://www.dartcontrols.com/

More additional information:
It looks to me like Currie Technologies offers some models with a 3X12V 36V battery package, 36V controller and 450W motor.

Answer 2

Assuming this is a DC motor, you need to exercise care in what you do. Energy density involves the amp-hours delivered at the voltage.
You can, in theory, design some-type of series parallel circuit to deliver 48 watts to the engine. You can also put in some type of circuit breaker to prevent an amperage overload.

Since an electric bike can be an expensive item, why don't you check with the motor manufacturer?

Answer 3

do what the sales guy tells you