Peak HP - Controller Have Enough Amps?

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DrkAngel
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Peak HP - Controller Have Enough Amps?

Post by DrkAngel » Feb 17, 2013 2:11 am

How to tell if your controller outputs enough amps to hit your motors full "peak watt output" - Horsepower.

You will need:
Speedometer & watt meter

Typically, a brushless hub motor hits maximum watt output at near 40% of no load speed.
Well, 1st you need to determine top no load speed.

Place speedometer on motor wheel.
Raise wheel and run at full throttle.
Observe top speed.
Peak motor output occurs at near 40% of no load speed (12mph if 30mph no load speed)
On road ...
Observing watt meter carefully, give full throttle.
Watts will stay the same till a decrease occurs.
This decrease occurs at the point where the motor accepts less watts than the controller can put out.
Repeat test, staying closer to this transition point, trying to pinpoint exact location, speed wise.
If this transition point is below the 40% of no load, then your controller is capable of full peak watt output - horsepower!
If higher, then you probably would benefit from a more powerful controller.

See - Determing Horsepower - Output Watts ... Simple Method!
Last edited by DrkAngel on Feb 20, 2013 11:27 pm, edited 2 times in total.
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DrkAngel
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Re: Peak HP - Controller Have Enough Amps?

Post by DrkAngel » Feb 18, 2013 11:02 pm

Example of controller being, and not being powerful enough to attain peak watt output.
11.6mph line is the 40% of top no load speed.

Image

For this setup, the 25a controller will not allow peak watt output - horsepower. (Dark red line)
The 35a does. (Light red line.)
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Last edited by DrkAngel on Feb 20, 2013 7:56 am, edited 3 times in total.
A little learning is a dangerous thing;
Drink deep, or taste not the Pierian spring:
There, shallow draughts intoxicate the brain,
And drinking largely, sobers us again.

I enjoy enlightening ... and enlivening the spirit of the innovators.

New & Improved - Acronym Definitions

Index - Homemade Battery Packs - Updated - November 2015

EBike Toolbox - Bargains! $

Endless Sphere Wiki

User avatar
DrkAngel
10 GW
10 GW
Posts: 4513
Joined: Dec 15, 2010 11:14 am
Location: Upstate-Western-Southern Tier NY. USA

Re: Peak HP - Controller Have Enough Amps?

Post by DrkAngel » Feb 20, 2013 11:49 pm

Thread restored and most links repaired!
Thanks
~DrkAngel
A little learning is a dangerous thing;
Drink deep, or taste not the Pierian spring:
There, shallow draughts intoxicate the brain,
And drinking largely, sobers us again.

I enjoy enlightening ... and enlivening the spirit of the innovators.

New & Improved - Acronym Definitions

Index - Homemade Battery Packs - Updated - November 2015

EBike Toolbox - Bargains! $

Endless Sphere Wiki

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