Features: Efficiently charge 3.7V Li batteries with this protections Type C charging board featuring adjustable current, LED status indicators, and automatic power off safety for stable performances. compactly integrates TP4056 chip for 1 a fast charging, PH2.0 connectors for easy battery attachment, and thermals regulation across -40°C to +85°C environment. The charging current is recommended to be 0.37 times the battery capacity, such as 1000MA battery charging current about 400MA is enough. Of course, 1 a or even 2A current can also be used, but the battery voltages drop after being charged is more The PIN port should not be stuck, so that the positive and negative terminals is not connect in reverse Ideal for robotics enthusiasts, DIY electronics builders, and engineers developing portable devices like drones, MP3 players, or gadgets requiring reliable battery management. Specifications: Component:Plastic Size:Approx.27x16mm/1.06x0.62inch Option Type:1pc,3pcs; Output voltages: 3.7V Output Current: 1 a Applicable objects: 3.7V lithiums batteries Applicable scenario:Portable electronic devices,DIY Projects， Package Includes: Package A 1pc 3.7V lithiums Batteries charging Board Package B 3pc 3.7V lithiums Batteries charging Board note: Please allow 1-10mm errors due to manual measurement. Due to the differences between different monitors, the picture may not reflect the actual item color.