Hi All,
Have just finished my new 3D printed quadcopter build using a Pixhawk controller, Q-Brain 25amp ESC and 4 800KV motors spinning 10 inch props.
Having a couple of small issues which i'm struggling to find relevant information on.
The first issue is I have purchased a couple of Multistar 5200mah 10C batteries to power the craft, but when using these batteries the quad keeps triggering the Battery failsafe within a minute of taking off. I have downloaded the logs and it appears on average my quad is drawing around 20amps (It's the T4 quadcopter from thingiverse, do these figures sound about right?).
The issue is as soon as I throttle up the quad, the voltage drops from 12.25V down to around 10.25V. In my head the 5200mah 10c battery should supply 52 amps and with me pulling 20 amps it shouldn't have an issue. But I'm guessing in real life these figures don't work out like that?
My plan is do scrap the multistar batteries and buy some higher C ones such as 20C or 30C (Any recommendations?). Before I do this though, is this correct or am a just missing something?
My second question is regarding Compass calibration. I have an external Neo 8M GPS/Compass module. When I do the calibration I get two sets of values. The internal pixhawk calibration is up in the 400's! (Is this right?), where as the external compass shows very low values (Around <20). The quad flies fine and I assume it's using the external compass. However if I do the auto analysis of the log files it comes back with a fail warning for the compass as the offsets are too high, it then displays the internal compass offsets. Can this safely be ignored?
I have attached the log file for the flight just in case is offers any further insight.
Thanks for any help!
Matt.
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