i'm running an F550 frame with an APM (hkpilot 2.7) and E300 propulsion system (15A Opto esc's).
Whenever i'm in the air the battery voltage drops below 11 volts with a fully charged pack. My current readings are around 20A at full throttle. Im using 30c - 60c batteries.
I've plugged an external voltage alarm to the balance lead to check if the power module is misreading the values but they are correct. I've also tried 40 -80c and 4s 40 - 80 c batteries but no luck.
Upon landing the voltage goes back to where it should be.
My system has one battery powering the apm via power module. All the fpv equipment gets the power directly from the battery.
What could be the problem?