Amp draw
#2
Need more information
Eg, How many turn is the motor.
At how many Volts that you want to messure amp draw.
Each motor is always different as well.....
Could only give a rough guide only even with all the details.
Eg, How many turn is the motor.
At how many Volts that you want to messure amp draw.
Each motor is always different as well.....
Could only give a rough guide only even with all the details.
#5
Tech Master
Joined: Jan 2003
Posts: 1,296
From: NSW Australia
I thought it would of been a lot more?
Say you are getting 10mins from a 3300mah battery (and ur getting 3300 from the battery so maybe ur using a 3600 :P ). That means your pulling a average of 19.8 amps (3.3amps/hr = 19.8amps in 10mins). Now, thats if your on the throttle that whole ten mins, and ur not so lets say ur on it 75% of the time. thats now 29.7 amps.. ?
Drop the runtime down to 5mins and we have almost 60 amps at throttle usage of 75% of the time? That seems way too much - where have I gone wrong?.
(ok you also have servos, receiver but im talking roughly rough...)
Say you are getting 10mins from a 3300mah battery (and ur getting 3300 from the battery so maybe ur using a 3600 :P ). That means your pulling a average of 19.8 amps (3.3amps/hr = 19.8amps in 10mins). Now, thats if your on the throttle that whole ten mins, and ur not so lets say ur on it 75% of the time. thats now 29.7 amps.. ?
Drop the runtime down to 5mins and we have almost 60 amps at throttle usage of 75% of the time? That seems way too much - where have I gone wrong?.
(ok you also have servos, receiver but im talking roughly rough...)
#8
When a motor is actually in a car then the amp draw will be a lot higher than what i mentioned above because of the extra load that the motor has. EG: Weight of the car, Gears, friction, tractionof the track etc etc
Amp draw on a motor which isn't in a car is around 10-15amps or there abouts....
Amp draw on a motor which isn't in a car is around 10-15amps or there abouts....
#10
Tech Master
Joined: Jan 2003
Posts: 1,296
From: NSW Australia
Because 60amps is average of "on throttle time" - you have huge amps from stand still / low rpm and they decrease as RPM increase (more RPM = more generated power limiting current flow.. - the motor becomes a generator, the generated voltage limits flow of current coming in because its got its own current trying to get out).
Stall a motor out and see how many amps you get - its like a short.
Stall a motor out and see how many amps you get - its like a short.
Originally Posted by Rossco
so if ur drawing say 60 amps why are speed controllers rated to over 300 amps and still only handle a 8turn?
#11
The initial current on an electric motor is very high, a 60amp + peak for a few ms would not be out of the question. Thats why the speedies are rated so high, to be able to handle the initial current at startup.
DC
DC
#13
A motor under a set load ie: Fan, will give a constant amp draw but off road cars even 540,s can draw over 100 amps, it's all load . Bumps and jumps
This is why speedys have peak amp draw @ around 360 amps.
Think about it how much current is drawn when you nail a wall with your car.
If you have a charger like the LRP and you run the motor run in feature have it set at say 3-5volts, then grab the spinning arm and you will see the amp draw jump.
And most likely the unit will shut down.
The old Tekin discharger had a race simulator discharge which would have the amp draw "spike' to get the batterys used to racing conditions.
This is why speedys have peak amp draw @ around 360 amps.
Think about it how much current is drawn when you nail a wall with your car.
If you have a charger like the LRP and you run the motor run in feature have it set at say 3-5volts, then grab the spinning arm and you will see the amp draw jump.
And most likely the unit will shut down.
The old Tekin discharger had a race simulator discharge which would have the amp draw "spike' to get the batterys used to racing conditions.



