ProTek RC 1S LiPo Transmitter Battery (Sanwa M17/MT-44) (3.7V/3000mAh)
How should the battery be inserted into the transmitter?
A suitable foam should be used to pad the battery in the transmitter battery compartment to help hold the battery in place and prevent it from moving around. Place a piece similar in size to the battery into the transmitter battery housing under the battery, and then while pressing lightly on the battery, slide the cover over the battery.