Brushless vs brush @ energy consumption
#1
Brushless vs brush @ energy consumption
I was wondering if I take an equivalent brush motor compaired to brushless motor lets say a 17.5 bushless vs a 17.5 brushed with a Lipo battery... which motor is going to run longer? if we give them the same abuse not talking about speed or torque just run time
#2
Brushless are reported to run loner. I am not going to state it as absolute fact because I have not done an actual comparison. However, you will notice brushless motors have less resistance than brushed motors. You can see this when spinning the motor shaft with your fingers. In addition, BL have bearings whereas a brushed stock usually does not.
#3
Tech Champion
iTrader: (515)
Brushless will run quite a bit longer as they are alot more efficient. However, especially in the case that you describe. A 17.5T brushed is a lot hotter than a 17.5T brushless so that would also casue the brushed motor to use more current. 17.5T is stock in brushless. You can't compare them turn for turn.
#5
Tech Master
iTrader: (10)
efficiency, runtime, heat, and power all go hand in hand.
Brushed effiecency is around 60%, where brushless is anywhere from 75 to 94%, depending on the motor(94% motors are not available to the public yet)
For runtimes comparing equivilant motors you are looking at a 20% to 35% longer run time for the brushless over the brushed motor.
Brushed effiecency is around 60%, where brushless is anywhere from 75 to 94%, depending on the motor(94% motors are not available to the public yet)
For runtimes comparing equivilant motors you are looking at a 20% to 35% longer run time for the brushless over the brushed motor.
#6
efficiency, runtime, heat, and power all go hand in hand.
Brushed effiecency is around 60%, where brushless is anywhere from 75 to 94%, depending on the motor(94% motors are not available to the public yet)
For runtimes comparing equivilant motors you are looking at a 20% to 35% longer run time for the brushless over the brushed motor.
Brushed effiecency is around 60%, where brushless is anywhere from 75 to 94%, depending on the motor(94% motors are not available to the public yet)
For runtimes comparing equivilant motors you are looking at a 20% to 35% longer run time for the brushless over the brushed motor.
#8
It's more about the efficiency of the ESC. BL motor's have a very low resistance per phase. Only like .0005 ohms if it's a good one. That means that alot of current can flow through it without being converted to heat. So, yes BL motor are way more efficient. Brushed motors have coils that have more resistance, especially through the brushes. They're also noisier.
-Tony
-Tony
#9
Tech Master
iTrader: (10)
4700kv x 2s(7.4v) = 34,780 rpms.
Now remember your battery is not going to run a 7.4 constently, and turns and kv's are different between motor manufacturers. Now in theory you can run a more effiecient set up with a lower KV motor and HIger volts to creat the same RPM, with less heat and longer runtimes.
So if you run it with the same motor on 3s it would be like this, and probably not last very long.
4700kv x 3s(11.1v) = 52170 rpms
That would be alot of heat, so to get more efficency and the same general speeds as before you would want a lower kv/higher turn motor.
3000kv x 3s(11.1v) = 33300 rpms
So you end up with longer run times, less heat, and less stress on the esc and motor. But you also have to remember you are adding weight to the car as a trade off. And its all theory, motor companys vary not only from company to company, but from motors to motors.
As for the high efficency motors, it has been done in lab settings so far, just look up brushless motor 94%, I think there is even video somewhere, but people tend to forget how much you lose again through the drivetrain, more if its not setup right.