Note: today's candidate pool was heavy on AI-automation clickbait and generic Make.com tutorials. This TP4056 UPS build was the only genuine hardware project in the batch, though the title carries some viral-bait hashtags.

Most home routers run on a 12V wall wart, which means a five-minute power blip drops your WiFi for the ten minutes it takes the router to reboot and re-negotiate. A DIY 12V UPS is a satisfying weekend project that fixes that, and it's a great excuse to learn some genuinely useful power-electronics building blocks.

The TP4056 is a cheap single-cell lithium charging IC that handles constant-current/constant-voltage charging and undervoltage protection — the same chip inside countless USB power banks. Pairing it with a boost converter to hit 12V, plus a switchover circuit that keeps the router on mains until the power drops, teaches you the core anatomy of every UPS you'll ever build: charger, battery, converter, changeover.

Even if the presenter's build has rough edges, watching someone stack these modules on a small board is a much faster way to understand the topology than reading datasheets. Bonus: the same pattern scales to backup power for a Pi, a camera, or a mesh node.