I've been getting into electric conversions for the past 8 months or so, with a few successful builds now! There are however, a few concepts about electric motors that I've been curious about and haven't been able to completely wrap my head around. And that is size and peak wattage of various motors.
So take for example, this large QS Motor that I've recently got for an ATV conversion: https://www.qsmotor.com/product/8000w-mid-drive-motor/
It is around 45lbs, is rated for around 32kw peak, and 8kw continuous. I own one myself and from my personal experience, it is a very powerful motor and I am very impressed with it.
I've also seen large RC motors that have a rather high power rating. I've stumbled across this animal the last couple days, and I am simply in shock. https://www.mgm-controllers.com/en/lmt-30100 It says this thing weighs around 5lbs and can put out 40kw!! That's over 50hp meant for an RC car!! I can't even fathom that. This motor is definitely at the top of its class, nonetheless there are still other RC motors rated at a very high wattage for their size as well.
So my question is, how on earth is this possible? How can a 5lb motor be rated for the same amount of power as a 45lb one?? This seems simply unbelievable. I realize that they are extremely different in terms of torque vs rpm. That small motor can probably rev to an insane amount. But you would think that the math (torque x rpm = power) would still work out in the favor of the larger motor, being as there is probably more copper inside the motor. I am very familiar with gas engines, and how high revving street bike motors can put out a ridiculous amount of power simply because they shift their power-band to high in the rpm range... But that's a combustion engine, and that involves a lot of different factors. So can anyone explain to me how such small motors can be rated for such high power?
To add to the questions and make things more confusing for myself, I also see very high powered RC speed controllers. Again, take for example this bad boy: https://www.mgm-controllers.com/en/tmm-80063-3-for-cars-x2-series-pro It says it's rated for 1000 amps peak, and it's sized for an RC car. My APT 96800 controller meant for an ATV (which puts out alot of power) has got to be like 8 times the size of that thing. How on earth is that possible? That's gotta be as much power as a mid-size Zero Motorcycle but placed in an RC car. I'm just blown away. Am I missing something here?
So take for example, this large QS Motor that I've recently got for an ATV conversion: https://www.qsmotor.com/product/8000w-mid-drive-motor/
It is around 45lbs, is rated for around 32kw peak, and 8kw continuous. I own one myself and from my personal experience, it is a very powerful motor and I am very impressed with it.
I've also seen large RC motors that have a rather high power rating. I've stumbled across this animal the last couple days, and I am simply in shock. https://www.mgm-controllers.com/en/lmt-30100 It says this thing weighs around 5lbs and can put out 40kw!! That's over 50hp meant for an RC car!! I can't even fathom that. This motor is definitely at the top of its class, nonetheless there are still other RC motors rated at a very high wattage for their size as well.
So my question is, how on earth is this possible? How can a 5lb motor be rated for the same amount of power as a 45lb one?? This seems simply unbelievable. I realize that they are extremely different in terms of torque vs rpm. That small motor can probably rev to an insane amount. But you would think that the math (torque x rpm = power) would still work out in the favor of the larger motor, being as there is probably more copper inside the motor. I am very familiar with gas engines, and how high revving street bike motors can put out a ridiculous amount of power simply because they shift their power-band to high in the rpm range... But that's a combustion engine, and that involves a lot of different factors. So can anyone explain to me how such small motors can be rated for such high power?
To add to the questions and make things more confusing for myself, I also see very high powered RC speed controllers. Again, take for example this bad boy: https://www.mgm-controllers.com/en/tmm-80063-3-for-cars-x2-series-pro It says it's rated for 1000 amps peak, and it's sized for an RC car. My APT 96800 controller meant for an ATV (which puts out alot of power) has got to be like 8 times the size of that thing. How on earth is that possible? That's gotta be as much power as a mid-size Zero Motorcycle but placed in an RC car. I'm just blown away. Am I missing something here?