"True" Power Rating of 48V1000W Yescom Kit

[wesnewell]

At least their site agrees that it's a continuous usage rating, which I've been saying from the beginning.

The number 1000W doesn't derive from any exact methodology regardless of what they say on their site. -Justin

I was referring to this statement on your website.
*Relative power is just a ballpark number for what the hub can produce continuously at ~300 rpm without any risk at all of overheating.
And I do believe that is what the numbers are for. From the start of this, I've always stated that the rating is for continuous usage, not a max power rating. That was one of the points being debated as far as I know.

 

[dogman dan]

Very true darkangel, there are multiple ways to climb a hill without wasting energy into heat. Climbing hills half throttle can be the way to go, particularly if you pedal hard to keep speed from dropping too low.

I've climbed 10 mile long mountain passes with grades of 7% continuous and 10% peaks similar to Alp D Huez in length and grade with excellent efficiency all the way by riding half throttle and pedaling briskly but not super hard. I was riding a 2807 9c winding, on 48v. Keeping the motor turning just 10-12 mph was plenty at half throttle, and the motor never got seriously hot during the entire climb that took one hour.

At full throttle up that hill for that long, I would have had a much hotter motor by the top, and have used up more of my capacity when I needed it most on a 70 mile tour.

But if the grade had been only 5% the whole way, I could have easily charged up the hill quite efficiently WOT, which would have been at about 18 mph. Efficiently in terms of wasted motor heating that is. Of course 18 mph is less efficient than 12 mph because of drag.

As always, "it depends".

 

[speedmd]

Good point Dogman. BTW got a great kick watching your vid of you mushing the crew. "Gee" for right, "Haw" for left. Did this a bunch when we had a few young sled dogs, mostly on skis as we had one difficult dog that would not stay focused enough to make it safe on wheels. "On by" was always a issue with one. Miss them all now.

Yes, if you can program the CA to alarm or show "time to heat sensor cutoff" (at this power level), you could dial the throttle as needed, or limit the amps a bit. Kinda like the instant gas mileage gauge in the car. Agree colder outside temps and speed play a key role in cooling curves.

 

[DrkAngel]

I was riding a 2807 9c winding, on 48v. Keeping the motor turning just 10-12 mph was plenty at half throttle, and the motor never got seriously hot during the entire climb that took one hour.

Wow! Yours is one of the motors that can use 150A input! ... @ 1mph!
Hub Motor and Ebike Simulator
9C 2807 @ 48V 50a vs 100a controller

1mph WOT
35A controller w/48V - 1592w electrical input - 152w motor output - 1440w damaging heat - overheat in 2.1min.
150A controller w/48V - 4613w electrical input - 187w motor output - 4426w damaging heat - overheat in 37sec.
35a to 150a = 23% watt output increase, from a 307% watt input - usage!

5mph WOT
35A controller w/48V - 1592w electrical input - 455w motor output - 1137w damaging heat - overheat in 2.9min.
150A controller w/48V - 3808w electrical input - 770w motor output - 3038w damaging heat - overheat in 55sec.
35a to 150a = 69% watt output increase, from a 267% watt input - usage!

Maximum sustainable heat production is (1209w electrical input - producing 927w mechanical energy = ) 282w heat energy. (1209 - 927 = 282) WOT - 22.7mph w/26" tires, continuous-sustainable.
282w heat production is this motors maximum sustainable heat production limit! (Unless you add auxiliary cooling method.)

@ 48V your peak watt output is 1250w = 1.67hp. (50A controller, or higher) (@14mph w/26" tires) Overheat in 3.7 minutes!

 

[justin_le]

@ 48V your peak watt output is 1250w = 1.67hp. (50A controller, or higher) (@14mph w/26" tires) Overheat in 3.7 minutes!

Hey DrkAngel, also be sure to read the explanation note about the "overheat in..." in the simulator description text, just in case you or others are taking this number tooo literally:

Overheat In: This is a prediction on how long it would take the motor to overheat (reach 150oC) based on a simple first order thermal model that assumes the motor is not spinning and in still air. The actual time to overheat on a vehicle moving outdoors and associated air cooling would be substantially longer. It none the less provides a good relative indicator of how much the motor is being stressed until we develop a more complete model.

We've got all the bits and pieces in place to do a really comprehensive set of thermal tests on motors that are spinning in outside air, which I imagine will more than double the thermal dissipation capability. I hope to get to that soon. The number that shows now is exceedingly conservative since it has the convective cooling in a worst-case scenario (stalled motor in still air). -Justin

 

[speedmd]

We've got all the bits and pieces in place to do a really comprehensive set of thermal tests on motors that are spinning in outside air, which I imagine will more than double the thermal dissipation capability.

[/quote]

Great Justin, look forward to adding oil / cooling fins / both, whatever it points to doing.

 

[justin_le]

At least their site agrees that it's a continuous usage rating, which I've been saying from the beginning.

The number 1000W doesn't derive from any exact methodology regardless of what they say on their site. -Justin

I was referring to this statement on your website.

Oh, my mistake I thought when you said their site it was in reference to the Yescom 1000W figure.

From the start of this, I've always stated that the rating is for continuous usage, not a max power rating. That was one of the points being debated as far as I know.

On this point that's how it should be for sure. To the extent that there are power ratings on motors from a manufacturer, it is generally for the continuous and not the peak power output, at a known set of operating conditions.

This is how it has been at least in industries where the motors are sold for engineer types. But when the watts becomes a selling point number for consumers, then it usually shifts over to first being the peak power and then the peak input power, to even a worse case surge input power from the moment a machine is plugged into a load.
If you look at electric rider's site, they take the very simplistic power = volts*amps approach, regardless of the actual motor being run:
http://www.electricrider.com/crystalyte/index.htm

I do see the appeal of this because it more closely matches the watts that someone sees if they have a watt-meter display on their bike, even though the maximum output watts will at most be about 65-70% of the quoted system power. When dealing with the masses, this means way less explaining to do. And, it also means a bigger number. My hunch is that over time this will be the norm for how 'watts' is used in the ebike industry in USA. In Europe, the situation is the opposite where it is a disadvantage to have a motor advertised as more than 250W, so you'll see vendors adopt the most conservative rating scheme possible.

For the sake of those confused:

• Motors by themselves do NOT have a power rating without a context of an operating voltage and RPM. You can't just say "this is an XXX watt motor". It doesn't mean anything.
• When supplied as part of a system with a controller and battery, then there IS a very exact peak wattage and less exact continuous wattage that can be determined. However, determining this is not very easy without dyno data which most people and most vendors don't have.
• When people have a watt-meter on their system, they can see the input watts. This requires very little equipment to get, and the peak input power of volts X controller amps stays steady for large portions of a ride. Therefor, the norm for rating ebike systems in this industry will probably wind up being the max input power.

 

[liveforphysics]

Thank you for taking the time to save me time Justin my dear friend.

 

[DrkAngel]

It seems that legal definitions of ebikes rate the motor watts as output power!

Laws - Legal limitation of motor by watt output.

Australia - "... power output not exceeding 200 watts"
New South Wales - "... maximum engine output is less than 200 watts"
Victoria - "... provided the motor's maximum power output does not exceed 200 watts."

Canada - "an attached electric motor of 500W or less"
Alberta - "... providing they do not have assisted speeds higher than 32 km/h (20 mph), or an electric motor producing in excess of 500 Watts (0.671 hp)."
Nova Scotia - "a power-assisted bicycle as a bicycle with an electric motor of 500 watts or less,"
Saskatchewan - "must have engines with 500 watt power or less"
United Kingdom - "require that the motor has an average power output limited to 200 W (250 W for tricycles and tandems),"
EU-definition electric cycle - not universal but " 250 W on bicycles" is common
India - "Vehicles with below 250W"
New Zealand - "with motor output power of less than 300W are classified as "not a motor vehicle". "
United States - "an electric motor of less than 750W (1 hp),"

Worldwide, the watt rating is output watts - horsepower.
As the standard, for legal - legality purposes anyhow.
I would have to expect that anything sold, rated for legal use anyhow, would use this same output watt = horsepower standard!

From a legal standard, if the eBike is being rated for sale, for "legal" road use, the eBike would have to be rated as the peak watts of output power - HP (Horsepower).

Of course, if the bike is for off-road or illegal use then the gloves might come off, any twisted perversion.
Throw on a powerful enough controller and a "legal" 750w peak output motor, at the same rated voltage, can draw 3000w - so a 3000w rated (battery-controller-motor) eBike? ... Not on my watch!
Worse! That 3000w input rating is at the most inefficient point of the eBikes power output, the 3000w peak input might be outputting 150w ... at 1mph! Oh! Even with a potential 3000w input the peak output is still the same 750w!

Sorry ... I just can't condone, or take any part in allowing such an unethical-deceptive-twisted "rating".
I "must" speak out - fight against it.

After all ... we don't want to seem related to politicians!

PS I never intended to state, or imply, that a motor is rated at a specific output. Rather, that a motor at a specified voltage has a specific peak output - watts.

More controller amps, beyond the needed for basic max peak output watts, is only a factor at lower rpms. The 9C motor mentioned previously outputs maximum power-watts-hp from a 50A controller, it will accept power from a 150A controller but only at low speeds and by increasing inefficiency horribly.
Never increasing peak output power-watts-hp!

 

[etriker]

Heinzmann hub motor watts is not the same as Golden Motor hub watts.

The Heinzmann 500w 36v motor would put way more power on the wheel than the GM 500w 36v setup.

The Heinzmann has better watts.

Justin is telling the truth.

 

[RLD70]

Which Clyte motor has the closest output power to compare with yescoms motor? I still want a torque motor over a cruise or speed motor and I know that Clyte has 2 48v systems with the choice of torque or speed.

 

[999zip999]

Dogman running a 2807 ? I love my 2810 and I don't have the top speed but speed is over rated on the street with a bike. So love it when I go over 25mph and see the the amps or watts go way down. Only go 28mph on 82v 28a. 2300watts but love the low speed wind for being effient at a speed that dosn't get me pulled over and wouldn't heat going up on the hills. Still about the only one for miles with a bike over 20mph and love it so I won't be making any for anybody. It would be like telling everyone my surf spot.
I guess what I'm saying is better to have a motor that is harder to melt.

 

[wesnewell]

Which Clyte motor has the closest output power to compare with yescoms motor? I still want a torque motor over a cruise or speed motor and I know that Clyte has 2 48v systems with the choice of torque or speed.

HS3540/HS3548 is the closest. If you're looking for a high torque motor, the gm MP, or clyte HT series would be what you would want in a DD motor. I'd go with the MP and external controller. And then there's Hubzilla if you really want the torque and speed.
http://greyborgusa.com/products/motors/hubzilla/

 

[justin_le]

Throw on a powerful enough controller and a "legal" 750w peak output motor, at the same rated voltage, can draw 3000w - so a 3000w rated (battery-controller-motor) eBike? ... Not on my watch!

Sorry ... I just can't condone, or take any part in allowing such an unethical-deceptive-twisted "rating".
I "must" speak out - fight against it.

DrkAngel, myself and probably most people here are behind supporting you 100% in that battle! And we will do our 2 bits to keep system watts referring to the ballpark output power that a setup can sustain without cooking, and not anything deceptive.

Just be aware we are up against against marketing forces that have what appears to the layman to be a simpler and more understandable scheme, not to mention larger numbers. It will get pretty futile. The whole more turns = higher torque motor misunderstanding is a good example of how the difficult to understand truth doesn't usually win against an easily understood falsehood. :x

-Justin

 

[DrkAngel]

Throw on a powerful enough controller and a "legal" 750w peak output motor, at the same rated voltage, can draw 3000w - so a 3000w rated (battery-controller-motor) eBike? ... Not on my watch!

Sorry ... I just can't condone, or take any part in allowing such an unethical-deceptive-twisted "rating".
I "must" speak out - fight against it.

DrkAngel, myself and probably most people here are behind supporting you 100% in that battle! And we will do our 2 bits to keep system watts referring to the ballpark output power that a setup can sustain without cooking, ...
-Justin

I don't see how it would be possible "to keep system watts referring to the ballpark output power that a setup can sustain without cooking"?

 

[salty]

Interesting stuff and glad to "spark" (pun intended :lol: ) this technical debate. I'm just happy to have purchased a kit that delivers what was advertised and can handle the additional juice...

Hi wes,

I have a question about the yescom Kit, more specifically the controller.. what is the max voltage you can use with the controller? 60v ?

salty

 

[dogman dan]

In general, best to start new threads for new questions.

I believe the controllers have at most, 63v capaicitors inside. That's typical for many "48v" controllers, but we need Wes to confirm it as fact.

 

[DrkAngel]

I don't understand most everyone's inclination to rate a motor system by sustainable heat dispersion???
Or input watts! ... ?

 

[Dauntless]

... I just can't condone, or take any part in allowing such an unethical-deceptive-twisted "rating".
I "must" speak out - fight against it.

DrkAngel, myself and probably most people here are behind supporting you 100% in that battle! And we will do our 2 bits to keep system watts referring to the ballpark output power that a setup can sustain without cooking, ...
-Justin

I don't see how it would be possible "to keep system watts referring to the ballpark output power that a setup can sustain without cooking"?

And I can't see the way to make the 'Ballpark Franks' joke that's so clearly called for by this.

 

[DrkAngel]

Throw on a powerful enough controller and a "legal" 750w peak output motor, at the same rated voltage, can draw 3000w - so a 3000w rated (battery-controller-motor) eBike? ... Not on my watch!

Sorry ... I just can't condone, or take any part in allowing such an unethical-deceptive-twisted "rating".
I "must" speak out - fight against it.

DrkAngel, myself and probably most people here are behind supporting you 100% in that battle! And we will do our 2 bits to keep system watts referring to the ballpark output power that a setup can sustain without cooking, ...
-Justin

I don't see how it would be possible "to keep system watts referring to the ballpark output power that a setup can sustain without cooking"?

Wasted watts is what cooks a motor!
Not "output power" or even input watts ... but lost input power - heat production!
At low rpms the heat production is massive with minimal output power!
At median rpms the heat production is moderate with substantial output power!
At high rpms the heat production is minimal with moderate output power!
The only constant factor in heat production is wasted watts - heat!
You would have to rate system watts referring to the ballpark wasted power that a setup can dissipate without cooking. ?

You could "keep system watts referring to the ballpark output power that a setup can sustain without cooking". But you would have to specify, rpm, throttle position, acceleration, resistance, speed, wind speed, grade, load, terrain, tires, tire pressure etc, etc, etc.
Way too many variable factors ... too complex for anyone to manage! ... ???

Much simpler to just rate by system peak output watts, like all the countries that legalize eBikes do.
I explained a simple way to self-determine your eBikes peak watt output - peak horsepower.
See - Horsepower - Output Watts ... How to determine!

 

[migueralliart]

I run mine at 12S lipo with a 50 amp controller all day long.

Currently vented plus upgraded phase wires. Also installed a temp sensor switch with a buzzer and it has never gotten hot to activate it.

People seriously underestimate these kits. They can put out some good amount of power down.

What top speed are you getting with that setup?

Sorry for the late reply

Anyway I'm running it at 120% with a lyen controller -- so far getting ~ 30mph steady and my temp switch is not activating the buzzer so it is not overheating.

 

[michaelkramer11]

Does anyone know how many magnet/poles are in this yescom 1000w rear motor? Need to know so I can properly set up my cav3 to properly read the speed via the hall sensors.

Thanks!!