The battery is where it for shielding reasons. It's part of the controller and memory section of the unit, which is basically a computer. Boogie has it sectioned off like that to prevent the controller section from creating noise and interference in the "tone and tubes" section of the circuits. Plus, the design of the unit is so far beyond user serviceable (for most people anyway... [insert evil laugh here]), they figure you would have to bring it in to be serviced anyway. Enjoy. It's a great unit. I sold mine and miss it.