The 3S 10A Li-ion 18650 Charger Protection Board Module is designed for 3-series 18650 lithium-ion battery packs with voltages of 10.8V, 11.1V, or 12.6V. It provides essential protection features, including overcharge, over-discharge, overcurrent, and short-circuit safeguards, ensuring battery safety and longevity. Ideal for DIY battery packs, e-bikes, drills, and portable devices.