MP wanting to turn right while flying straight

[Tshred57]

Yesterday I took the Mavic out to do a range test - 2 3000mah LiHVs attached with 3M Dual Lock.
I started flying and quite quickly the aircraft started wanting to turn right with no stick input. No IMU or compass errors.
I thought perhaps a battery had come loose, flew back and had a look - no issues.
So I flew out 6,000 feet or so (empty farmland), got tired of all the swerving, and hit RTH. I got not much higher than 200' at any point.
The craft flew straight as an arrow back to my position.
I uploaded the flight to Airdata, and there were a couple of oddities - Mode changed to GPS Atti (Atti mode, right?), mode changed to Wi-Fi Reconnect, then a meter later changed back to GPS Atti. I also had a couple of instances of Downlink data connection lost - both at close distances (4 meters for 7.9 seconds and 266 meters for 1.2 seconds).
There were plenty of satellites available (14-18 through the flight) and Kp index very low.
Is there any way I can figure out what the issue was?
Can the craft fly if the main battery shuts off (say the main battery had less voltage than the aux. batteries)? It was very bright and hard to make sure the main batt. was on.
Any opinions or suggestions would be appreciated.

Tom

 

[Qoncussion]

Simple! Try recalibrating the RC. You'll find the option to do so buried in the RC tab of the GO4 menu. If that doesn't do the trick, recalibrate both the compass and IMU (regardless of the "normal" status). If that doesn't work... Finally, try flying anywhere else - as you might simply have been near some sort of magnetic or RF interference.

 

[locoman]

how were your extra batteries attached. Did they put the MP out of balance.

 

[Tshred57]

Thanks, I'll try it. I flew this morning with 2 1300mah LiPos and had no issues. This was in my neighborhood - I'd think there'd be lots more interference here than over farmland that I've flown over lots of times, just hadn't used the big batteries there before. I was thinking perhaps the batteries were causing the issue but I know lot of folks have used them.

 

[Tshred57]

how were your extra batteries attached. Did they put the MP out of balance.

3M Dual Lock on each side of the MP and equal points on the batteries. I don't have a way to know if it's perfect, but it certainly looks darn close, both on the ground and in the air. Multistars - very tight fit. The wires had to run under and around the front legs.

 

[Tshred57]

Simple! Try recalibrating the RC. You'll find the option to do so buried in the RC tab of the GO4 menu. If that doesn't do the trick, recalibrate both the compass and IMU (regardless of the "normal" status). If that doesn't work... Finally, try flying anywhere else - as you might simply have been near some sort of magnetic or RF interference.

Okay I recalibrated the RC and we'll see what happens - can't hurt! It's not the most obvious procedure the first time you do it but YouTube to the rescue. Thanks for the advice!

 

[Odom1957]

Mine did this and I had to recalibrate the joysticks to solve it. It would literally start turning left with my hand completely removed from the left stick.

I have since bought the stick protector that goes on before I put it up.

 

[Tshred57]

Happy Independence Day to those in the US! Happy 4th of July to most everyone else.
Just an update. Yesterday I calibrated my RC and compass. Today I flew with both 3000mah LiHV batteries - got out to 7000 feet and again, wanted to turn right. I fought it for another 3000 feet, lost connection, and hit RTH. So, I used just the regular battery and flew past 7000 feet no problems. Any ideas would be appreciated. I've flown to 20k feet at this location with 2 1300mah LiPos. I'm at a bit of a loss.