I was descending rapidly and near the ground when my aircraft developed a severe, uncontrollable wobble. As it was descending, I had the alert that says "Battery communication error", with the bold letters "MC". I do not take off with less than six satellites (Icon blue), and calibrate the compass before EACH flight. The bird would not respond to the controller. A screen shot shows 4 satellites in an area where I normally get 12. What happened? It flew normally after I recovered...no harm done. But this is alarming. Did I descend too fast and hit "dirty air" the way a full size helicopter does, causing the wobble? Then the battery was stressed? I need input on whether to send it in to check its systems. Thanks.