Interesting, When my Blade is hovering about 3 or 4 feet and I give it full throttle and it barely climbs if at all, thats when I disconnect my lipo and its measuring about 10.8-10.6. Also when I use the symmetrical blades, my vertical performance is poor, very slow to climb. With flat bottoms I have plenty of power. I'm using E-power 1320 mah batteries I found for 20$ each. Could that be the reason? Otherwise they work great, I getting about 25 min flight times. Or do I need have to go to 800-900 mah to get decent performance with the symmetrical blades?