21700 Battery Case 4‑Slot DIY Power Bank Enclosure with USB C Fast Charging and Overcharge Protection

Compact 21700 Power Case for DIY power banks, Black Build a portable power solution without soldering. This lightweight, compact case holds four 21700 batteries and includes builtin battery management to protect against overcharge and overdischarge. Fast charging and multiple output options let you charge phones, tablets, and other USB devices on the go. Key benefits Easy DIY assembly with no soldering required, ideal for hobbyists and DIYers. Large capacity support: accepts 4 x 21700 batteries for extended runtime. Builtin protection circuitry for overcharge and overdischarge safety. Fast charging performance for quick device ups. Portable and lightweight design for travel, camping, commuting, and emergency backup. Performance and compatibility Number of batteries: 4 x 21700 (batteries not included) Color: Black Nominal output power: 22.5 W, typical up to 27 W USB A output: 5 V / 4.5 A, 9 V / 2.5 A, 12 V / 1.87 A Note: when multiple ports are used simultaneously, output defaults to 5 V only USB C output: 5 V / 3.10 A, 9 V / 2.22 A, 12 V / 1.67 A USB input: 5 V / 2 A USB C input: 5 V / 3 A, 9 V / 2 A, 12 V / 1.5 A Note: simultaneous input using both ports is not supported Use scenarios Travel: assemble a capacity power pack to charge phones and small devices during flights or long journeys. Outdoor activities: power phones, cameras, or lights while camping or hiking. Daily carry and emergencies: keep a modular backup power source for commutes, unexpected outages, or roadside needs. What is included 1 pc power case (batteries not included) Important notes 21700 batteries must be purchased separately. Please allow up to 1 mm variation due to manual measurement. Product color may vary slightly from images due to monitor differences.