3000w on 500watts motor
- Thread starter lithail
- Start date
Generalizations are not useful here, except to say pushing the limits on any component is going to reduce reliability and longevity.
You can only establish with specific IRL testing, just how quickly that "eventually getting hot and frying" happens with **this** motor, or **that** one.
Before that happens yes, both more speed and torque.
The controller also has a lot to do with it, and limiting power based on temperature feedback, as with CAv3 is the cheat code.
You can only establish with specific IRL testing, just how quickly that "eventually getting hot and frying" happens with **this** motor, or **that** one.
Before that happens yes, both more speed and torque.
The controller also has a lot to do with it, and limiting power based on temperature feedback, as with CAv3 is the cheat code.
dogman dan
1 PW
The standard recipe for a cheap 40 mph e bike is a cheap 500w rated dd motor, typical in the 48v 1000w kit. Then you put it on a 72v 40 amps controller. Run it on a battery strong enough to handle 40 amps without huge sag under load, typically 72v 10 ah of RC type lipo. (cheapest battery that strong)
The result is you can run 40 mph for about 10 min, then the voltage drops enough to lower top speed to about 35 mph. If you have a battery bigger than 10 ah, the motor melts, in about 50 min. With a 72v 10 ah battery you get about 40 min run time on flat ground.
Put the same rig on steep enough single track, and the motor can melt in 15 min.
This is not idle talk, or speculation, I was melting motors for a job for awhile. I did testing to destruction for an e bike company, since I live in hot desert, near long steep hills.
What happens is there is not really enough copper in the thing to handle the 3000w, so a significant amount of the watts you pour in turns into heat. So if you run more than 2000w worth of throttle for long, you melt shit. Often the hall sensors cook off first, but I have seen flames coming out of the cooling holes in a motor I ran at 4000w.
Best advice is stick to 48v or 52v, and run at most a 40 amps controller. You still get a lot more torque, but not a huge lot more speed, and the motor has a good chance of not overheating, unless you run it up long, very steep, hills.
You can very successfully run 72v for a long time, but you just can't run wide open much, or climb very long hills. So it just depends how you ride. You can have the 3000w briefly when you need it, but never melt the motor if you back off quick enough.
500w geared motors work best limited to 48v. 72v cooks them off very fast.
The result is you can run 40 mph for about 10 min, then the voltage drops enough to lower top speed to about 35 mph. If you have a battery bigger than 10 ah, the motor melts, in about 50 min. With a 72v 10 ah battery you get about 40 min run time on flat ground.
Put the same rig on steep enough single track, and the motor can melt in 15 min.
This is not idle talk, or speculation, I was melting motors for a job for awhile. I did testing to destruction for an e bike company, since I live in hot desert, near long steep hills.
What happens is there is not really enough copper in the thing to handle the 3000w, so a significant amount of the watts you pour in turns into heat. So if you run more than 2000w worth of throttle for long, you melt shit. Often the hall sensors cook off first, but I have seen flames coming out of the cooling holes in a motor I ran at 4000w.
Best advice is stick to 48v or 52v, and run at most a 40 amps controller. You still get a lot more torque, but not a huge lot more speed, and the motor has a good chance of not overheating, unless you run it up long, very steep, hills.
You can very successfully run 72v for a long time, but you just can't run wide open much, or climb very long hills. So it just depends how you ride. You can have the 3000w briefly when you need it, but never melt the motor if you back off quick enough.
500w geared motors work best limited to 48v. 72v cooks them off very fast.
wineboyrider
1 MW
john61ct said:
Or even a bbq temperature probe and a 3 way power switch.
dogman dan
1 PW
I got to where all I needed, was to drill a tiny 1/8 hole in the cover, to smell the motor and know when to stop. I had drilled big holes to cool the motor faster, and learned the smell. Later on I had a motor I just rode in the wet a lot, so I put tiny holes to prevent water build up inside. It was just enough to let me smell toasty, and stop in time. You do have to pause to smell it though.
MadRhino
100 GW
FUN
That is what happens. Still, the real fun begins around 10kw.
Will it fry?
Not right away.
Not if you are conscious of the limits. Temp limit, time limit. Components limits.
We’ve been doing this for more than a decade. Over powering electric motors is common and easy. Your cheap 1000w kit can do 50 mph and accelerate cars, still lasting pretty long. You need controller mods (or a bigger controller), bigger wires and connectors, high C rate batteries... and a better bike eventually: stiffer frame, better brakes, suspension, wheel building...
Now we have choice of bigger motors, that we can over power even higher, longer, safer.
That is what happens. Still, the real fun begins around 10kw.
Will it fry?
Not right away.
Not if you are conscious of the limits. Temp limit, time limit. Components limits.
We’ve been doing this for more than a decade. Over powering electric motors is common and easy. Your cheap 1000w kit can do 50 mph and accelerate cars, still lasting pretty long. You need controller mods (or a bigger controller), bigger wires and connectors, high C rate batteries... and a better bike eventually: stiffer frame, better brakes, suspension, wheel building...
Now we have choice of bigger motors, that we can over power even higher, longer, safer.
markz
100 TW
Magic Smoke
MadRhino
100 GW
Like most of us building performance, HobbyKing.comlithail said:
RC lipo can also be purchased direct from manufacturers. Yet Hobby King has experience shipping fast and reliably. First learn about RC lipo, charging, monitoring, maintenance and safety.
dogman dan
1 PW
Fun even happens when you melted the motor. Temp monitors definitely help. At one point, all I wanted was to get home on my daily commute without melting motors. Starting out with brushed hub motors, I found they melted fairly often climbing the hill to my house. Big hill, hot summer days.
I put a simple remote thermometer intended for use in cars on the axle of the motor. Outside the motor, just inside the dropout notch and behind the nut.
No, it did not give me real time temps, or actual temps. But I could see what I needed. Is the temp still going up? Is it going up fast? I learned a number I stay under, and the motor would not only not melt, but not discolor the windings. It was around 150 f or so, near the limits of the device.
But for really beating on motors, most want the vent holes anyway. They do not that much to extend run time, but the very very effectively let the motor cool off faster when you stop riding. And then, you smell the windings, and can see through a half inch hole if its golden, golden brown, or just turned black and smoke is coming out. Put the holes near the edge of the cover, so you can actually see windings.
I put a simple remote thermometer intended for use in cars on the axle of the motor. Outside the motor, just inside the dropout notch and behind the nut.
No, it did not give me real time temps, or actual temps. But I could see what I needed. Is the temp still going up? Is it going up fast? I learned a number I stay under, and the motor would not only not melt, but not discolor the windings. It was around 150 f or so, near the limits of the device.
But for really beating on motors, most want the vent holes anyway. They do not that much to extend run time, but the very very effectively let the motor cool off faster when you stop riding. And then, you smell the windings, and can see through a half inch hole if its golden, golden brown, or just turned black and smoke is coming out. Put the holes near the edge of the cover, so you can actually see windings.
DogDipstick
100 kW
MadRhino said:
I will often say that used EV lipo > HK lipo.
HK lipo is junk IMO.
I did this same and so far my super powerful EV lipo cost 1/2 the price and lasted 4x longer than any HK lipo I ever had.... More power than I could use on a bike from the cheapest of the lithium cells.. shouldnt pay more than 100$ for a Kwh (1000Wh) ... but HK lipo costs about 100$ for 125 Wh (0,125KWh) .....
But carry on..... Not for beginners. Safer though IMO.
999zip999
100 TW
This is a geared motor ? If so when over volted they get fast and they get hot and sometimes just melt the plastic gears before something else. A cheap DD 500watt motor is better. But what is needed is 3,000 watt muxus or the em3ev one with Moto rim
markz
100 TW
999zip999 said:
Yeah 3kw mxus, or 3kw qs, or a 1500W leaf if that 3kw is much less of the time, otherwise 3kw mxus/qs or 5kw, but 5kw has a wider flats so need a fat bike I'd think.
stew007
10 W
I did a swiss cheese mod to the side plates to a Crystalyte 408 running on 20s, drilling lots of holes on both sides, its still running fine 11 years later, heat was the problem running high wattage on a sealed hub motor, the heat builds up very quickly without ventilation so its not all that usable, if you can find a way to cool it its possible to make this simple efficient setup very enjoyable, just dont run it too hard for too long, even after its swiss cheesed it might still be possible to cook the motor if you cane it going up a long up a hill etc, but I find its easy to tell or feel when your riding it if the motor is getting too much of a pasting, and its time to back off a bit.
DogDipstick
100 kW
markz said:
Yeah I absolutely love my 35H magnet 200$ Qs 205V1 1000w....Bought on Amazon.... runs 3kw pretty good and peaks over 2.5X that.... 3Kw. 135mm dropouts and has a 7 speed freewheel, so it is convenient to install. It is a 35mph bike. @ 8.5kv on a 24" wheel, @ 26" wheel you would go a little faster than that. I do automated thermal rollback though certainly and the 200$ QS has a sensor installed.
999zip999
100 TW
You should have 28 mm magnets. Some 1500 watt motors have 35 mm and the muxus 3000 has 45 mm magnets 3000 watts into 35 mm magnets AR a match. Yes you can use the 28 mmmm 500-watt motor but you have to learn how to not to melt it the one with the most experience melting those motors would be dogman.
Okay so I have been thinking.
I currently have my 500W motor hooked up to a 1000w speed controller.
So it was 500w@48v=25amp draw.
Now its 1000w at 48v = 33amp draw.
but it only draws about 8 more amps than original at full throttle. So my question is how many amps will it draw with a 3000w controller hooked up. I dont understand how to calculate the amp draw because the numbers don't add up.
I am currently making a 72v+ battery. that I will try and test with the 3000w controller. My controller is 40-84v @3000w I am just waiting for some connectors to come in the mail to try it at 48vx3000w. I just don't think its going to make much difference until I use it at 72v. is that correct?
Or is it the controller limiting the amperage output and that's why there isn't a huge change in the amp draw?
Thanks
I currently have my 500W motor hooked up to a 1000w speed controller.
So it was 500w@48v=25amp draw.
Now its 1000w at 48v = 33amp draw.
but it only draws about 8 more amps than original at full throttle. So my question is how many amps will it draw with a 3000w controller hooked up. I dont understand how to calculate the amp draw because the numbers don't add up.
I am currently making a 72v+ battery. that I will try and test with the 3000w controller. My controller is 40-84v @3000w I am just waiting for some connectors to come in the mail to try it at 48vx3000w. I just don't think its going to make much difference until I use it at 72v. is that correct?
Or is it the controller limiting the amperage output and that's why there isn't a huge change in the amp draw?
Thanks
markz
100 TW
48v x 25amp draw is 1200W
48v x 33amp draw is 1584W
36 x 25 = 900W
36 x 33 = 1188W
V times A is watts
48v x 33amp draw is 1584W
36 x 25 = 900W
36 x 33 = 1188W
V times A is watts
