Throttle not consistant

When I connect my battery and open the throttle to 50% the current draw on the battery is 13A. If I then go to full throttle and back to half throttle it is now spinning slower on half throttle and the current draw is only about 8A. 50% throttle stays like this until I disconnect the battery.

What could be causing this.

The ESC is a 50A Hobbyking. max currect draw is 36A. 4 cell lipo at about 3.9v per cell.

Can you connect your RC receiver directly to your ESC, bypassing the ArduPlane hardware and do the same test? That will inform whether this is an ESC issue or something to do with ArduPlane.

Good idea. Will do soon and let you know.

That’s because you need to do ESC calibration,or ESC is “discovering” new max value every time you hit full throttle.

It does it without the Pixhawk in the system so it’s an ESC issue.
I’ve done a simple calibration by turning it on with throttle full open then closing when it beeps etc but no difference.
Is there something else I should do to calibrate the ESC?
Thanks

The calibration you mention should be the correct one. Hold it at full throttle long enough for the first set of beeps, but don’t leave it so long that it enters programming mode.

From the manual:

1.Switch your Transmitter ON and set the throttle stick to its maximum position.
2.Connect the battery pack to the ESC. Wait for about 2 seconds, the motor will beep
for twice, then put the throttle in the minimum position, the motor will also beep, which
indicates that your ESC has got the signal range of the throttle from your transmitter.