Just received my CF dual battery mount and Y-cable for flying with two batteries, got everything set, and went out for a test. With two batteries, anti-jello mount and NO camera I only got 5 1/2 minutes flying time, compared to 8 minutes on a single battery. Thinking I had mad a mistake, I did it again with the same result. This makes absolutely no sense to me...I knew I wouldn't double the flight time but I did think I would get a few extra minutes. Any ideas?