Walkera36 controless flight
Hi, I hovered the walkera36 15min with brushless motor, ESC tower pro 30A and lipo 11.1v-1800mAH 10c all ok, I changed lipo a 11.1v-2200aAH 10c then problem, more power was used to get off ground and when it did sprang up to 1 foot where I hovered it, 2min into hover heli pointed skywards and started going backwards, hit ground and lucky training gear was on did no damage, the whole time I pitched forward and cut throttle but nothing happened, heli stopped on its own, this happened the following day to. Glad I wasn't ant higher than 1 foot from ground. Anyone HELP