Selecting battery sizes for portable speakers influences playback hours, weight, and charging behavior. Small devices often use 10440/14500 or integrated pouch cells; larger Bluetooth and party speakers favor 18650 or prismatic modules for extended runtime and fast charging. Battery sizes for portable speakers must balance continuous discharge capability for amplifiers and DSPs with capacity and safety. SUNJ ENERGY’s cells deliver consistent capacity, low self-discharge, and tight dimensional control—ideal for compact enclosures and scalable BOMs. We assist manufacturers with cell selection, testing, and supply chain reliability to ensure long runtime, consistent audio performance, and compliance with transport and safety standards.