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View Full Version : Does battery pack size effect Amps used ?


woody
12-08-2005, 09:43 PM
I have a KV1048 motor on 3s Lipoly rated at 10 amps
The instructions state 3xLipo use 9.47 Prop, i have bench tested the motor using a 1700mah 11.1v pack with a 7x3.5 prop and its drawing 9.80Amps with a 8x4.3 its drawing 18.50Amps so i reckon the motors no good
What i am unsure about is if i used a lower pack ie 650mah would this lower the amp draw or should a motor draw the same current regardless of the pack size mah

Woody

slipstick
12-08-2005, 09:51 PM
In theory a motor should draw the same current regardless of the pack capacity. Only changing the voltage/number of cells should make a corresponding change in current.

But in the real world you can fall over the fact that smaller batteries will not deliver so much current as larger ones....however you should never rely on this to limit the current. Running batteries right up to their current limit can do serious damage to them.

Steve

woody
12-08-2005, 10:03 PM
Thanks Steve
What you are saying is that the battery mah does not effect motor only the flight time, looks like the motors gone , its new so i will have to return it

Woody

Geoff_Gino
12-09-2005, 06:15 AM
I have a KV1048 motor on 3s Lipoly rated at 10 amps
The instructions state 3xLipo use 9.47 Prop, i have bench tested the motor using a 1700mah 11.1v pack with a 7x3.5 prop and its drawing 9.80Amps with a 8x4.3 its drawing 18.50Amps so i reckon the motors no good
What i am unsure about is if i used a lower pack ie 650mah would this lower the amp draw or should a motor draw the same current regardless of the pack size mah

Woody

Hi Woody

From what you have said here the correct prop for that motor is the 7x3,5 as it is drawing the correct current. As you load the motor up with a bigger prop the motor will draw more current. So your test seems quite correct.

The battery will deliver whatever current the motor demands as long as it can, and if it is to much the ESC cut-off (if set up correctly) should shut off the motor and so protect the battery.

Don't give up on that motor.

Geoff

timocharis
12-09-2005, 07:05 AM
woody,

I agree. That motor's no good! Even worse, you could mess up a smaller battery trying to run it max all the time (the ESC cutoff will probably work, but not before you've messed with your battery a bit. Its life can be shortened).


Dave

woody
12-09-2005, 06:36 PM
Thanks Everyone
I have returned to motor to the retailer , they are going to test it and let me know.

Woody

hoppy
12-09-2005, 07:31 PM
What brand motor is it?