I bought an ErleCopter3 and tried to fly it, but I still not able to do it. I performed all the pre-flight tests and calibrations; however, the drone didn’t fly correctly: the drone started yawing. I tried different modes, checked the motors rotation, calibrations, etc., but the drone continue rotating on itself. During the tests I got a low battery voltage alarm, so I charged it. However, I noticed that the charger is not working as expected: there are only two red LEDs working (the third one is not working at all).
After investigations I found that the yawing issue is maybe caused by the battery that doesn’t deliver enough energy for the 4 motors. But now, I am not sure if there is a problem with the battery or the charger (or both of them). It seems that the battery is dead: the current voltage of the battery is 4.7V, and is not charging anymore.
Please see the videos below.