Hello all. I am new to yuneec but not new to RC's nor drones. I recently got a Q500 1080p for 100 bucks. I knew the batteries were shot but I didn't think the replacements would be so expensive. I'm opting for 3rd party batteries, already made a adapter for my batteries. But I usually fly 2200mah and smaller for my other aircraft. So what would you all suggest as the most power dense battery that will fit in the space provided, or what is the biggest battery I can strap to the outside to achieve the best balance of power to weight to attain longer flight times? And this may be crazy, but has anyone upgraded this quad to a 4s system? I assume all it would take is new motors, ESC's and a BEC for the power to the flight board, but would love to know if anyone has done this.