Ideal volt/current depends on the motor design (Stator length, diameter, material [thickness if frequencies are used], magnets, air gap, wire diameter/resistance, etc.
Its hard to line everything up for a “perfect” or “magic” setup.
Depending what you read.
It’s said motors are most efficient running at a very high percent of their no-load rpm. ((The no-load speed is the max speed they spin with no resistance)). This no-load is adjustable with either more or less voltage and more or less turns of wire around the tooth. This is the most important reason to adjust voltage. Other than this purpose where you are designing the system to run within the optimal rpm range using greater voltage enables you to simply have thinner battery wires. But…another important variable is the esc and what voltage and amperage it runs most efficiently at and I believe, but don’t know for sure, escs like to pass as few amps as possible. So…ultimately…the higher the voltage the more efficient system as long as the motors use puts you at …let’s say 75% of the no-load speed
And that’s what they say but…who here rides around at one speed! If you really want to find what voltage you would be most efficient at you could ride your normal route AT THE SPEED YOU DESIRE, see how many amps were spent, try it again with more or less voltage, and see how many amps you spend. Doing that you’ll find the real variable is how fast you want to go. you can go up a steep hill using a high kv mixed with high voltage but it will suck a huge amount of amps. in practice, likely because of ohm’s law, the greater the voltage the easier it is to push the current, and you will get up that steep hill much faster with a low kv and also save your amps. I’ve ridden 80,90,100kv up the same hill, all with almost the same other variables, and the 80s go up faster.
every other aspect of the motor…size,magnets, length, whatever, can be accounted for looking at the Kv and you can forget about them As long as the motor is big enough for the job though. In fact having too small a motor for the job is the number one reason to sink into inefficiency. There are other more powerful motor designs for their size out there other than the radial “outrunner” motor. Axial flux “pancake” motors and the new confusing transverse flux motor. Haven’t read this and am surprises…it looks readable: http://www.mht.bme.hu/~bilicz/compumag2013/files/pa3-11.pdf
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YASA was axial.
All good stuff, Hummie. Thumbs up.
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