"I figured out what was happening. Turned out to be nothing to do with the mah of the battery. Mission planner was resetting the Battery "Sensor" setting in Mission planner to "other" even though i had selected 3DR power module. This seems to upset…"

"Thats just pure logic Steve. Good idea, i'll give that a go over the weekend."

"Thanks for the reply CyberCrash, but my quadcopter used always work with the 1600s. It's a very light frame, Something happened lately to change that. I don't know if it's a mis setting in mission planner or the new 3.1.15 firmware."

"Hi Gustav, i've had the quadcopter about 8 months and the 1600s were my first set of batteries. I was always able to fly it with the 1600s, something is after happening of late to change that. But i don't know what. "

"Ya, i noticed this myself a few days ago. Had to connect mission planner to it again to switch to X but, i had never set it to + in the first place. Weird. But don't think it's related to this instance."

"Hi crady, I did think of that but it shouldn't be an issue. The battery is smack in the middle."

"I neglected to say that those batteries used work fine. But I have changed so much in the last week that I don't know what's causing it. Upgraded software to 3.1.15 etc, new compass etc.

How can I tell how much current is being used?"

"I have same issue, I've outlined it here, http://diydrones.com/forum/topics/compass-calibration-always-above-150

Again it's an APM RC Timer clone"

"Just to add to the above. I've also just tried removing the board completely from the quadcopter and calibrating it on it's own without any connections other than the usb lead from my laptop. Same issue. So it's either the board or something that…"

"Guys, i think my problem is outlined here:

http://diydrones.com/forum/topics/arducopter-v3-01-fly-away-with-no...

Fix described here: https://www.youtube.com/watch?v=wN0c0bKlFUs
and hopefully fixed…"