luketheduke
New member
Most modern ESCs will detect low voltage or voltage sag and cut power to the motors. It looks exactly like what I am seeing in this video. Modern ESCs sense the voltage drop and they bring the copter down "gently".
When testing my new Alien I was using old 4S 30C lipos. They were voltage sagging in seconds as the copter drew more current than the old 30C lipos could provide. It looked EXACTLY like your video. After a minute or two the copter would just sink to the ground and no increase in throttle would make a difference. Testing the lipo after showed a solid 4v + per cell.
Under load the voltage was dropping close to 3v per cell but after the motors shut down the lipo showed 4v per cell. The ESCs were detecting low voltage under load and bringing the copter down.
I suspect your issue is one of available current. 20A is not much power. I think your ESCs are detecting voltage drop due to current restrictions and setting you down gently to save the lipo the ESCs think they are connected to.
The power supply I am using has a built in ammeter, and when I fly, it registers always less than 10A nominally 5A. When running with a 3S 2200mah LIPO I still get the same problem. It may be due to PIDs so I have tunedit as best I can and will try more hovering soon. Thanks for all the help so far!