Translations:KAVAN Alpha 1500 V2 - Instruction manual/160/en

From KAVAN RC Wiki

Loading the transmitter batteries

Remove the battery hatch located on the back side of the transmitter pushing the cover at the arrow mark with your thumb. Load 4 fresh alkaline batteries or AA-size accumulators carefully keeping the correct polarity (marked on the bottom of the battery holder). Plug the battery holder cable into the socket at the bottom of the battery compartment keeping the correct polarity (+) red wire, (-) black wire. (The transmitter features a protection circuitry – if you connect the plug the other way around, the transmitter will not work, but will not be destroyed by reversed polarity.)