Working on an electronics project that needs to charge a 3.7V lithium battery? These tiny charger boards are super handy. They use a USB Type-C port for input (5V, 1A), and output 4.2V to charge a single lithium cell. Each board includes over-charge, over-discharge, and over-current protection (cuts off at 2.4V/4A). There's an LED that glows red while charging and turns blue when full. They're perfect for DIY stuff like powering small gadgets, modifying toys, or building custom battery packs. You get 20 boards in the pack, which is great for prototyping or stocking up. Important: these are for single cells in parallel only (don't connect batteries in series), and you need to connect power first to activate the protection circuit. If you're new to this, watch a tutorial online first. A super useful component for any maker or tinkerer's toolbox.
