I will do some testing on my e bike how does it affect the Whkm, with bikes Field weakening is super common.
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Wh/Km should be the metric sought after here.
Quantify any gains or losses in efficiency.
We’re running axial flux motors with a kv of 5-10 at 600V. Field weakening has much less of an effect
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I read any vesc that can use 5.3 firmware or higher can use field weakening. What’s the cheapest hardware that can run 5.3? I’m trying to find the cheapest smallest vesc to put on a scooter to make it faster.
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VESC 4.12
$82 brand new, delivered in the USA
But the real answer is “something used, gotten at a great price”. I bet you could score a used 4.12 for five bucks if you looked long enough. I bet you could find a used FOCBOX for $50 which would be a lot better than a 4.12.
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That costs
more than the 84100 which has phase wire sensing, and higher voltage, and probably other features I don’t know of. Why anyone would want the 4.12 I don’t know.
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Well the 4.12 is pretty obsolete, but in general, a 60V ESC can definitely be better for 10S / 12S than an 84V ESC because you’re wasting less energy as heat.
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Would it? I assumed as long as running 10/12s battery it would be the same efficiency regardless of what max voltage the vesc could do.
An 84V ESC will get hotter than a 60V ESC at the same voltage & current level.
I could guess why. Why?
That statement is making way too many assumptions.
I get where you are coming from, generally speaking, higher voltage FETs tend to have higher drain source resistance.
I don’t really want to go into details but so many things affect the ESC temps, I could write an essay on it. TLDR is you really shouldn’t generalize this way if the engineer knows what he is doing. And if he doesn’t then don’t buy the product.
You can have 1.25$ FETs provide so much torque you can’t even use it all on an esk8 because you can spin all 4 wheels simultaneously on race tires while being geared close to 70km/h. While also being unable to overheat the hardware even during races pushing crazy power.
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We’re also talking about a decently made 4.12 vs a cheaply made 84100
Pretty much every 4.12 out there is following 4.12 schematic put out by vedder many years ago and it’s pretty much obsolete hardware at this point. You can have much better for much cheaper just by designing around currently cheap components.
The component cost of a decently powerful vesc designed to be made cheaply is about 30$ excluding the heatsink.
Just because they sell it expensive doesn’t mean it’s made expensive.
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Any updates on this? I managed to gain 4 mph on one of my boards running 25A FW Current Max and 85% FW Duty Start. Afraid to go higher untill I bypass the BMS. Haven’t noticed any range loss since running FW.
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Drop your fw% duty start down to 60% and retest. You should gain efficiency
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I’m going to try that, Thanks. I did notice that if i pick up the board and give it full throttle it acts weird without a load.
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So there’s a fine line between too many amps and too low of a duty cycle engagement point. You’ll have to play with these values (drop them 1 and try again) for amps.
With duty cycle engagement you’ll want to do the same, but raise the % until you get a smooth motor.
You want smooth running motors all of the time.
With the onewheel you can actually change the resistance of the motor and help with this issue. You might be able to try dropping motor resistance L down a few points and see if it helps. Just don’t go wild with throttle if its making bad noises. You can kill motors and escs i
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It would be cool if Vedder would drop some more insight on this
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I’m trying out some tiny tires.
So I flipped on Field Weakening on an Esk8 today.
Looks like I only gained a couple miles on the bench and maybe one mile in real life…
Not much testing so far…
Can I throw more amps at it?
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Throw more amps at it!
But bench test and make sure the motors run smooth before riding.
You’ll notice hall sensors being weird once you get the settings too high
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