A question: It is stated that you don't want to run your battery all the way down or you will ruin your battery. What does that mean exactly? I ran a battery to empty (well to 6-8%) which has maybe 10 charges on it. It seems fine. Should I worry that it might fall out of the sky at some point due to a battery failure, or might it experience shorter and shorter flight times? Has anyone actually experienced issues with running batteries to empty?