For electric drum magazine, it is 4x AAA battery required.

To install batteries, please open the left drum.

1. unscrew the 3 screws in the middle.
2. unscrew the 2 screws on the left drum.
3. open the left drum carefully.
4. you will see the battery compartment.
5. install 4 AAA batteries.
6. close the drum.
7. insert magazine to AEG.
8. use the tail button to roll up the mag.
9. ready to shoot.
10. If the winding speed is slow, its time for replacing batteries.