Noob Electronics Question: Idle Current

When you look at the big picture, you’ll find that the Chinese manufacturers have even less knowledge of electrical motor theory than we do here in this forum. They just make a motor that looks on the outside something like a real one manufactured by the west though they will cut many corners internally for ease of manufacture and lower production cost not knowing or caring about the effects of the changes, then they copy the specs from the original motors sheet and change them a little to make 'em seem legit, then they sell them to us on all over the world knowing that once we pay our money it wont matter if it doesn’t seem to perform that well and the battery got hotter than we thought it should and didn’t last long…

You may find these links interesting. The first link discusses no-load current as part of the “iron losses”, which come from hysteresis, eddy current in the iron core as well as mechanical losses found in the bearings. These will definitely still be there when the system is under load–the extra load from the prop is factored as “copper losses”, which is the power lost in the motor windings as heat. Truly optimizing a motor selection for a particular use-case will involve minimizing the total losses.


Thank you for answering the question. no-load current will still be there under load. @xfacta FYI

Hi Pontius Pilot @lordvon
I just want you to know I wasnt trying to troll you or be argumentative - I apologise that I came across that way.
I probably took your original post off on a different tangent than what you intended.

I do understand the no load current and the losses involved in running motors of various sorts - I’m not arguing with that at all.
I also see that you’re trying to measure the no load versus operational current to better understand your own motor choices and efficiency - and I applaud that. There should be more of it. Some manufactures dont provide such useful information, or it’s downright wrong.

So far the way I’ve approached this is more exploration in ecalc, looking at the motor temperatures (amongst other things) when trying to select a working system to put into practice.
I must admit I’ve never set out to deliberately test no load current, but we’ve all run our motors from a receiver and ESC to see what happens :slight_smile:
Probably my slant on this has been knowing the baseline data (such as current, hover throttle and so on) we can get out of ardupilot to better understand your own system, and look for changes over time that would indicate maintenance or reconfiguration is required.

Sorry to derail the discussion.

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