V5F+ Efficiency

[Jason McNeil]

The range I was able to achieve out of the V5F+ made me intrigued: it looks like Inmotion's controller is doing something special to eek out more efficiency than other Wheels. Cruising just under the limiter at an average 23-25kph uses just 270W. For the basis of comparison, I seem to recall that the KS 14" 800W uses 382W at an equivalent speed, while the Ninebot One is 340W. 

During acceleration there's a unique torque ripple sensation; closest similarity I can think of is when riding on a high speed train, when its going from 200 to 300kph zone. It doesn't feel unsafe in any way, off the top of my head, I'd estimate that it's in the 50-100Hz range.

Over the next week, I'll be doing some comparative testing with the 9B1, KS14C, KS16 for efficiency at various speed with video overlay.

[dmethvin]

This motor is super light for its size, right? I wonder how that affects the efficiency. There's less mass to provide a flywheel effect but that means the controller can apply torque more effectively for balance. Perhaps there's a direct correlation between motor+wheel mass and efficiency?

[Fahrtwind]

@Jason McNeil Good news. This is also an advantage in safety. Better efficiency means less heat! And this is the factor that may cause thermal limitations in speed, cut offs etc.The efficiency of modern brushless motors (e.g. my Pyro 700 from Kontronik in a 700 class helicopter) has a rated power of 4kW and an efficiency of more than 90%. It stays almost cool after flights...

What kind of diagnostic hardware/software are you using?

[HEC]

6 hours ago, Jason McNeil said:

it looks like Inmotion's controller is doing something special to eek out more efficiency than other Wheels.

Rather than to controller I'd contribute this mainly to more effective motor. It could be that it's both more efficient in general (better windings, magnets and / or alloy used) as well as optimized for peak performance just under the top speed. And indeed controller could be optimized as well - better MOSFETs with a littler bit less of losses or slightly different switching frequency might squeeze some extra saved watts as well. Hopefully same efficiency will be inherited also by V8.

[Jason McNeil]

17 hours ago, Fahrtwind said:

What kind of diagnostic hardware/software are you using?

It's a datalogger that connects from the battery-pack to control-board, called 'eLogger' from Eagletree. The cool thing is that they have modules that attach to the data collector like GPS, GForce sensors, RPM sensor, Temperature probes, it's as if it was designed for the Wheel in mind  

I've ordered another piece of kit on Monday that will be awesome when combined with this other stuff. More to follow... 

[EUCMania]

I remember it uses a higher voltage 74v, 2P20s battery pack, resulting smaller current and hence lower loss due to the internal omhs. Comparing with nb1's 15s, the voltage is 20/15-1 = 33% higher, and efficiency gain is 1-270/340 = 21%. Lighter motor shell reduces the demand of power for balancing which involves acceleration/deceleration hundreds of time per second, depending on its sampling/adjusting frequency. A lower sampling/adjusting frequency can also reduce energy consumption

 

[1kw]

sine wave controller, aluminum stator, tighter laminations in motor windings, plus higher voltage? This how the ebike world is changing, produces more power, range, and efficiency.