Cramming a lithium-ion cell, a tiny internal circuit board, a voltage step-down converter, and a live USB-C port right inside a tiny 1.5V cylinder is a safety and manufacturing nightmare.
�Unlike a phone or a laptop where there is dedicated space for a battery management system (BMS) with temperature sensors and thermal management, these tiny cells leave almost zero margin for error. If the internal protection circuit fails, or if a cheap component shorts out while someone is plugging it into a fast charger, you've essentially built a micro-incendiary device disguised as a household consumable.
�Lithium-ion chemistry hates being squeezed into tight, uncontrolled spaces without proper thermal management. Handing a consumer a literal loose cylinder with a direct charging port—expecting them to toss it in a drawer, a backpack, or a device without knowing its cycle history—is just asking for thermal runaway.
It's not just a half-measure; it's a structural safety hazard waiting to bite people.