Hi EP, the batteries are 3 button type. They are in the the "black" P1 that is removable just like in the TOS series. There is a little screw and door underneath it. Did you get it in the original box and all the instructions? The P1 and its batteries are the only power source for the whole phaser, it transfers power to the main body by 2 pins you see when you remove the p1. On top of the that P1 is the power clear power dial with numbers and it has 4 sound settings and an off, so make sure its not in the off position. Also on the side of the main body there is a silver knob that turns off and on the the lighted tip and when you turn the nozzle it also can turn the Led off. "I don't understand why it was made this way" One last thing cause I still dont know if you got the instructions is the P1 comes off with that little brown pin you pull out and works independent of the main body using the same dial on top just like when on the series they went on hidden weapon missions.