BT-20Wingman | Tactical power bank with detachable batteries

When a power bank dies you wait for a wall socket; when its built-in cells age, the whole brick becomes e-waste. EDC carriers wanted power that reloads like a magazine and can be maintained for years. BT-20 Wingman does exactly that: press the button, the bay ejects, and a charged 21700 or 20700 cell (18650 with adapter) brings it back to life, the meter reading the fresh cell automatically. 20W USB-C runs both ways at ~80% efficiency, a single 5000mAh cell refills an iPhone 15, and the unit doubles as a cell charger — with an optional 3D-printed dock kit for tinkerers. Launched in December 2023, the project drew 1,317 backers and raised about HK$695,000 (~$89,000) against a HK$50,000 goal — about 1,390% funded.