"True" Power Rating of 48V1000W Yescom Kit

geeeyejo1

geeeyejo1

1 kW
Joined
Dec 1, 2012
Messages
375
Location
New Jersey, USA
I was monitoring the Amperage and Wattage on my Wattmeter this afternoon on my return commute home. To my surprise during some periods of WOT I was peaking at 1500W+ to the motor. I assumed that my 48V1000W kit equated to a 20A controller coupled with the 50+ watts of a "48V" battery to provide 1000W max to the motor. My sunthing 48V15AH is spec'd to produce 30A maximum discharge and based upon generating 1500+W today it appears I must have a 30A controller then no?
If this is the case, then is my 1000W kit really 1500W?
Regardless - really happy with the performance of this setup - I didn't think that I would be able to hit the 27MPH max they stated due to my weight (240 lbs today) I am easily hitting that and with pedaling can hit 30 mph on the flats - very respectable performance IMHO....
 
Hub motor ratings ( unless you are ian.mitch or hipowercycles ) are based on continuous power capability, not peak.
If you put 2000W peak into this motor it wouldn't make it a 2000W motor.

So it sounds like this kit comes with a hopped up controller by default.
 
Here's how I gauge continuous maximum power.
1) install a temperature gauge (I like rc on-board sensors personally, but bbq sensors work too)
2) turn up your amperage and run a bunch of wattage through the motor until it reaches 110c
3) find the "butter zone" where you can dump the most wattage through the hub without making the temperature increase past 111c.

So far using this method I have determined the following maximum continuous for the "butter zone".
Crystalyte H series: 3200 watts
9c: 2700watts
magic pie 2: 2500 watts
GNG: 1600 watts

All these motors are "1000 watt" motors except for GNG which is a "500 watt" motor.
 
neptronix said:
Hub motor ratings ( unless you are ian.mitch or hipowercycles ) are based on continuous power capability, not peak.
If you put 2000W peak into this motor it wouldn't make it a 2000W motor.

So it sounds like this kit comes with a hopped up controller by default.
Click to expand...
Understood but this is currently a limitation of my battery not the motor. Seems similar hubs are all capable of 2000W+ continuous capability - hence with the controller provided seems like this is more of a 1500W kit...
 
Unless I'm mistaken, the yescom 48v 1000w kit comes with a controller closer to 30 amps than 20.

I'm not sure what it's real rating is. Most of my 20 amp controllers in reality are 22 amps. Controllers will also allow a brief amp spike, before they controll the power back down to normal. So my 40 amps controllers may allow a 60 amp spike that is very very breif. But it shows on the CA as max amps.

If you are seeing 1500w for more than a few seconds, then you must have a controller that is about 30 amps. But at full throttle on flat ground, I bet you see about 1000w max.

It would be a good thing with that controller and your battery, to pedal some, and use half throttle for the first 10 feet when you leave a stop sign. To make that amp spike a bit less.
 
dogman said:
But at full throttle on flat ground, I bet you see about 1000w max.

It would be a good thing with that controller and your battery, to pedal some, and use half throttle for the first 10 feet when you leave a stop sign. To make that amp spike a bit less.
Click to expand...
Actually was seeing the 1500W at WOT on flat ground cruising at about 25mph+ I have been following the technique described above - ie pedaling in conjunction with light throttle application from a stop to avoid the amp spikes - trying to develop those good riding habits early on!
 
I forgot, you have a bit more weight than I have. Being winter, you likely have some extra drag from the big coat as well. I tend to see about 30 mph on 1500w, but on my big heavy cargo bike, it can take a bit more.
 
All the yescomusa kits I've seen come with a 30A controller. Motor rating is for continuous 24/7 operation, not max power it will take for shorter periods. That motor can take many times 1000w. I put 4000W in mine regularly and it will take at least twice that nuch. If I ever get around to modifying my spare controller to 60A, at the 100V I run at that will be 6000W and I'm not worried about it for short burst. FWIW, all watt ratings on motors and controllers are for 24/7 operation. The stock controller is rated fro 800W, but can put out as many as 1800W at 63V. I changed the 30A output on a 500W controller to 45A 2 years ago and it's still working fine. Even at wot, you will rarely ever pull max amps.
 
Motors are rated by their output, (Honest ratings), not their input.
A 1000w motor could quite easily handle a 2000w input, while outputting much less than 1000w.
Typically a 1000w rated motor, with a good controller, might use 2000+w at a hard start, while outputting less than 500w.
Most of the energy wasted as damaging heat.
Optimally a 1000w motor at ideal load would use 1200w to cruise at a 1000w output.
 
Where did you come up with that definition of the ratings? That's just not right.
 
wesnewell said:
Where did you come up with that definition of the ratings? That's just not right.
Click to expand...
A 746w motor is a 1hp motor. (typically rounded to 750w)
Watts are a measure of energy, in the case of electric motors, watts are the output rating of energy, not rated by the input of electrical watts!

See Wikipedia Horsepower.

"Electrical horsepower

The horsepower used for electrical machines is defined as exactly 746 W. The nameplates on electrical motors show their power output, not their power input"


For example - Do the math on this motor.
"MY1020 36 Volt, 750 Watt, 2800 RPM, 27.4 Amp, permanent-magnet motor. 11 tooth sprocket for #25 chain."
36V x 27.4a = 986.4w input to produce 750 (1hp) output
Which, shows a motor efficiency of 750/986.4 or approx. 76% efficiency - reasonable for a brush motor.

My eZip motor.
MY1018Z 24 Volt, 450 Watt, 3000 RPM, 24.0 Amp, permanent-magnet motor.
24V x 24a = 576w input to produce 450w (6/9hp) output. 78% efficiency.

Find your motors v & a ratings and do the math.

The best permanent magnet motors output near 90% efficiency = 1000w input for a 900w output, while electrical induction motors might dip into the 60% range = 1000 watts input required to produce a 600w output motor.

And, these are the efficient ratings for the motors.
If you "lock test" a 24a motor, you might be able to dump in 100a.
This is similar to a heavy throttle start from a dead stop, just prolonged.
Smoke and flames are possible.

That is why the motor v & a specs are listed with the rpm also.
The peak, rated output at the optimal v x a @ rpm / efficiency.

Efficiency
Dead stop - efficiency = 0%, no matter how many amps you dump in!
Efficiency gradually increases till reaching reasonable at 50-80% of no load speed.
A more powerful controller, typically, only increases performance in this inefficient, sub 50% zone.
"At speed" the motor will draw no more amps than rated!
 
I think motor, and battery ratings vary wildly depending on who did the rating. Engineers say one thing, but all you see in any ad is what a salesman wants to call it.

Wes is quite correct though, that you can run 1500w through these motors all day without them melting, provided you aren't stalling the motor. Stalling is overloading it so it rotates too slow, such as towing a person on a skateboard up a steep hill over and over. Or towing too much trailer, or anything else that would result in 1500w going in resulting in under 10 mph of speed. You can get away with some stalling for a limited time, like climing a steep hill 1 mile long. But a very steep hill 10 miles long could be running too long in a low efficiency rpm.

If you are going 15-20 mph, 1500w won't melt the motor. Not even in my climate.
 
HP conversion has nothing to do with the electrical ratings motor manufacturers put on their motors other than that is the max hp you should run the motor at for continuous operation without failure. Why you seem intense on converting this to HP is beyond me, but yeah, you could say a 746W motor is rated at 1hp. There's still no difference in the rating. It is the max amount of power the motor should be used at for continuous operation. It has nothing to do with the amount of power, measured either way, the motor can produce. Since we're discussing electrical motors I see no need to convert watts to hp. A 746W motor can produce many times 1hp if given more current. Most manufactures will use very conservative numbers when setting specs on anything to avoid returns. Same goes for motors. I'd wager you don't limit your motor to the watt rating and there's no need to for less than 24/7 operation.
 
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... :D
 
DrkAngel said:
wesnewell said:
Where did you come up with that definition of the ratings? That's just not right.
Click to expand...
Click to expand...
A 746w motor is a 1hp motor. (typically rounded to 750w)
Watts are a measure of energy, in the case of electric motors, watts are the output rating of energy, not rated by the input of electrical watts!

See Wikipedia Horsepower.

"Electrical horsepower

The horsepower used for electrical machines is defined as exactly 746 W. The nameplates on electrical motors show their power output, not their power input"


Find your motors v & a ratings and do the math.

The best permanent magnet motors output near 90% efficiency = 1000w input for a 900w output, while electrical induction motors might dip into the 60% range = 1000 watts input required to produce a 600w output motor.

Good info. Some people will not believe published data no matter how many Engineers contributed to the findings.

I have a 600w BMC Torque motor and can slam 2750w into it for a second from a dead stop to get up a hill. Big deal.

But on the flat it eats only 700w to go 30 mph on a 55 pound bike/180 pound rider. Happy 600w motor.

Unhappy horse when I force it up a hill at 24 mph/1800w.
 
wesnewell said:
HP conversion has nothing to do with the electrical ratings motor manufacturers put on their motors other than that is the max hp you should run the motor at for continuous operation without failure.
Click to expand...
Look up any motor you can find that lists volts, amps and watt rating.
(Motor! Not controller!)
Pretty sure that V x A will be about ~20-25% higher than the watts.
This indicates that the motor at peak output is ~80-90% efficient.

Also look for the phrase "motor output" near the watt rating.

Any, even near reputable, manufacturer will use and advertize the output watts.

Otherwise the market would be flooded with 2000w super low cost induction (non permanent magnet) motors.
 
I don't care if its the output rating or input rating. It may well be an output rating The fact is is that it's the continuous operation rating. Not a max rating. And I'm pretty sure that was the original question.
 
wesnewell said:
I don't care if its the output rating or input rating. It may well be an output rating The fact is is that it's the continuous operation rating. Not a max rating. And I'm pretty sure that was the original question.
Click to expand...
Fact? ... I don't carelessly bandy around such important words.
With a 80% efficiency a 1000w rated motor would be 1250w continuous input.
Slower than top efficiency, full throttle at any lower speed would be higher than 1250w.
Hub motors are great heat dissipaters, a higher watt input might be tolerated for extended periods.
 
Well, if it's not a continuous operation rating, please tell us what you think it is.
 
wesnewell said:
Well, if it's not a continuous operation rating, please tell us what you think it is.
Click to expand...
For the 3rd time ... !!!
The 1000w rating is the motors maximum motor output! Peak hp - horsepower.
Optimal speed-optimal load ... 1000w = 1.34hp.

Please realize ... watt is a measure of energy, not solely electrical energy, all types of energy.
 
DrkAngel said:
wesnewell said:
Well, if it's not a continuous operation rating, please tell us what you think it is.
Click to expand...
For the 3rd time ... !!!
The 1000w rating is the motors maximum motor output! Peak hp - horsepower.
Optimal speed-optimal load ... 1000w = 1.34hp.
Click to expand...
Well that's just ridiculous. I think what you are trying to say is that is max output rating for continuous operation. That I would agree with, if in fact the rating is an output rating to begin with, which I'm not sure about. It could just a well be an input rating. One thing is certain. It's not a max/peak output value. One can increase voltage and amperage and far exceed 1000W output and/or input. The rating is exactly what I said it was. The max rating for continuous operation. Exceed it, and you are running over spec. I doubt there are many here that actually never run over spec.
 
motor-duty-cycle-types-as-per-iec-standards.jpg


The motor would need a S1 rating for a true continuous duty rating. IMO It would be any ones guess what the duty cycle was is if not rated.
 
wesnewell said:
DrkAngel said:
wesnewell said:
Well, if it's not a continuous operation rating, please tell us what you think it is.
Click to expand...
For the 3rd time ... !!!
The 1000w rating is the motors maximum motor output! Peak hp - horsepower.
Optimal speed-optimal load ... 1000w = 1.34hp.
Click to expand...
Well that's just ridiculous. I think what you are trying to say is that is max output rating for continuous operation. That I would agree with, if in fact the rating is an output rating to begin with, which I'm not sure about. It could just a well be an input rating. One thing is certain. It's not a max/peak output value. One can increase voltage and amperage and far exceed 1000W output and/or input. The rating is exactly what I said it was. The max rating for continuous operation. Exceed it, and you are running over spec. I doubt there are many here that actually never run over spec.
Click to expand...
Of course one can increase its output by increasing its voltage.
That is why it is rated 48V 1000w = 1000w output @ 48V = 1.34 peak hp!

Of course you can overvolt most any motor, but that would change its rating (and speed).
36V = 750w output motor = 1hp
48V = 1000w output motor = 1.34hp
60V = 1250w output motor = 1.67hp
72V = 1500w output motor = 2hp
All from the same motor
Higher voltage watt output rating would be skewed somewhat by increased friction and IR.

Increasing the available amps, at optimal hp speed, will accomplish nothing!(Unless you have a really wimpy controller?)
It is already drawing all it can take.
If you know anything about DC electrical motors you would realize that maximum amps is accepted at 0 - low rpms, as the rpms increase the accepted amps decrease until at max rpm the motor has no power output. It is only accepting the amps required to offset its own friction and resistance, near 0 amps ... trying to force in more amps is worthless.
The only way you can force in more amps is by upping the "pressure" = the voltage.
 
You are correct, that if you want to run this size hubmotor at more than 1000w, the best approach is to increase the voltage. Too many amps at 48v would tend to just make heat with the extra amps. But only till you got up to speed, so in most cases people get away with feeding the motor amps it can't use.

Just don't try that too much amps approach on a really steep and long hill.
 
You must log in or register to reply here.

Similar threads

K
40Ah Battery Options
Replies
1
Views
420
goatman
G
V
1st ebike. Yescomusa battery/controller options
2
Replies
38
Views
2,628
E-HP
E-HP
F
Just built my first ebike! What should I upgrade first?
Replies
10
Views
1,156
Drunkskunk
Drunkskunk
wturber
Using the Wangdd22 1500W 30A DC Boost Converter on an ebike
6 7 8 9 10
Replies
227
Views
45,509
docw009
docw009
J
Where to buy Crystalyte / Aotema 1000W+ kit? eBay kit??
Replies
7
Views
1,212
dogman dan
dogman dan
Back
Top