Servers by jDrones

Improper current draw in quad


(Joyraj Bhowmick) #1

Hello, I am using a 650mm Tarot frame with Emax 5210 290kv motors with 17x10 propellers with Li-ion batteries that can give a current of 120A. E-calc shows a current drawn of 30A per motor and thrust testing shows a current drawn of 25A for a motor. But when all the motors are used, a maximum current of 60A is reached. This was reached at 66% throttle and there was no increment in thrust or current drawn when throttle was increased from 66% to 100%. When the three motors was disconnected and only a single motor was used, a maximum current of 25A is reached, the same as in thrust test but all four motors draws a maximum of 60A and this current gradually decreases to 48A over the course of 15min. I have changed the firmware, Pixhawk, recalibrated the ESCs, changed ESCs but the result was the same. Any guidance/ help in this matter is highly appreciated.

I have also tested with LiPos that have previously given 80-90A on other airframes, but still the result was the same (60A max).


(Mike Boland) #2

You haven’t said anything about the current sensor you are using.
Is it a 3DR Pixhawk or one of the other varieties or a clone.

You need to calibrate the Current Sensor.
They are also not linear, so you need to get a couple of current readings and set the parameters accordingly.