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BrianG · 09.30.2008, 02:35 PM

Usually, each motor series has a rated max power value. Motors also have a max rpm. Then, each wind has a different kv value.

So, let's say a motor is rated for 1,000w, max rpm of 50,000, and a kv of 2000:
Voltage to get max rpm = maxrpm/kv = 50,000/2,000 = 25v
Current (using ohms law) = power / voltage = 1,000/25 = 40A.

On a 1512/2.5d (60k max rpm, 2050kv, 2000w surge power): Max v = 29.26v. Max A = 67.6A. But, they probably round down the voltage to a common lipo value, so the voltage becomes 7s (25.9). Max A then becomes 77.2A, which is pretty darn close to their spec'd 78A.

That's the only way I can think of that they come up with their numbers...

	(#17)
BrianG RC-Monster Admin Offline Posts: 14,609 Join Date: Nov 2005 Location: Des Moines, IA	09.30.2008, 02:35 PM Usually, each motor series has a rated max power value. Motors also have a max rpm. Then, each wind has a different kv value. So, let's say a motor is rated for 1,000w, max rpm of 50,000, and a kv of 2000: Voltage to get max rpm = maxrpm/kv = 50,000/2,000 = 25v Current (using ohms law) = power / voltage = 1,000/25 = 40A. On a 1512/2.5d (60k max rpm, 2050kv, 2000w surge power): Max v = 29.26v. Max A = 67.6A. But, they probably round down the voltage to a common lipo value, so the voltage becomes 7s (25.9). Max A then becomes 77.2A, which is pretty darn close to their spec'd 78A. That's the only way I can think of that they come up with their numbers...