Overvolt!

kevinmccune

Well-Known Member
Region
USA
well I finally got a donor bike for the "trego
' project,it takes a basically universal"Silverfish" battery with 4 pins 36 volt stock battery,it no "ball of fire"(hope that's not prophetic) can I drop a 48 volts on the mount without destroying anything( hopefully for a little more torque,don't really need the speed,yes I have ordered another controller and display,JIC,its 350 watt motor with help it handles most inclines around here,its just about convenience not top speed,finally got my old 500 watt full suspension basically running again it runs great with a little pedal help its never stalled on the steepest driveways,the caveat is the chain skips(is my chain too long?
 
The e-bike controllers I'm familiar with will take a certain amount of voltage boost. When the limit is reached, the controller will throw an overvolt error code and shut down before any damage occurs. I can't say for sure if this is the case with yours though. 12V or 33% is quite a boost though. The controller is one thing, the motor is another. Overheating or burning something is also a possibility.

If your goal is to use a 48V battery rather than a 36V, a safer approach would be to use a 48V to 36V buck converter such as this one:

 
Two choices in controller design determine whether over volting is possible.

The first is a an over voltage voltage detection circuit, Most often used in midmotors. NEver seen one in a hub motor controller,

The second is component choice. Maximum charge voltages on 48V and 36V batteries are 54.6 and 42V respectively. All 48V controllers use 63V filter capacitors, Some, but not all 36V controllers use 50V filter capacitors and will have shorter life if run on 48V. How short can't be predicted.
 
I don't think a higher voltage will get you more torque, but the motor will have a higher unloaded top speed determined by it's KV rating (rpms per volt). Of course more power will get you more torque and you can conduct more power with the same gauge of wire at a higher voltage. Power = Volts X Amps.
 
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