A:Answer Thanks for your question. Our JBL Boombox 3 is designed to operate in portable mode with its built-in battery, and it won't function without it. Replacing the battery can void the warranty and may affect its waterproof capabilities. If you're looking for a speaker that offers more flexibility with power options, we recommend checking out our latest models like the JBL Xtreme 4. It features both AC and battery modes, and the battery is removable, giving you more convenience and versatility.