I wanted to understand the current draw needed for my mini quad and I did below test. And I did it using the new Bonka 2200mAh 35C 3S from xyzhobby.com
Thought I will post the results here, may be useful for some one.
I am not an expert on Lipo or Electronics. Whatever I did and calculate is based on the knowledge I gained from Internet forums.
Any mistakes, please excuse me.
Quad specs,
Racerstar BR 2205 2300kv motors.
Racerstar RS30A Lite 30A Blheli_S ESCs
Omnibus F4 Pro v2 Flight controller running INAV 2.0.0
Gemfan 5030 2 blade propellers.
Quadcopter dry weight - 365gm, AUW - 552gm
Test Setup.
Quadcopter tied tp a chair with props mounted.
Watt meter connected between quadcopter and lipo
Throttle given at 70% (little above my usual hover throttle) continuous
Results
. Ran continuously till watt meter showed 1.5Ah(1500mAh) which is 70% capacity of 2200mAh lipo.
. Initial voltage on watt meter - 12.44v(no load) and at load - 12.11v(10 second waited)
. Flight time was 9 minutes 14 seconds.
. End Voltage was 10.95v (at load) After resting 10 minutes voltage showed 11.33v.
. 10~A current was drawn.
Does this mean I just need a battery with Not more than 20A discharge? Note: Also tested 100% throttle and watt meter reported 15A. . Other figures on watt meter after test, 97.8W, 17.1Wh, 10.59Ap, 10.93Vm, 127.Wp
. So based on calculation for Internal Resistance = ((resting voltage-load voltage)/Amp used) x 1000 ((12.44-12.11)/10A) x 1000 = 33mohms
. After resting 10 minutes, lipo was put for balance charging and each cell were showing 3.83v
. Balance charger showed 1481mAh loaded back to lipo. This also confirm the accuracy of watt meter.
Temperature During test,
. Lipo peaked 89F
. Motors peaked 91F
. ESC peaked 75F