Note: 18650 batteries are not included and must be purchased separately. Compatible only with 18650 cells whose positive terminal is flat. Please ensure the correct direction of the positive and negative when inserting. Designed for mobile use as a power bank case. This charging case supports up to 12 18650 batteries, which increases capacity and extends usage time. It features a digital display for power status and a built-in camping light to illuminate your surroundings. Ideal for DIY enthusiasts and makers; provides a simple process to create your own power banks. Use scenarios - Outdoor activities: camping or hiking where you need portable charging and lighting in one device. - Emergency backups: use at home or in a car during power outages. - DIY projects: build customized, higher capacity power banks for personal or workshop use.