I bought a Blade Inductrix and upgraded the motors to Tiny Whoop 19,000Kv, the batteries to Nanotech 200mah 35c - 75c 1s and added an FPV cam. It flew ok with no mods but now it will only fly for 10 seconds before it plummets to the ground. When I check the batteries the voltage is 4.00v so I can't understand why it won't fly. Can anyone help?!?!