Features: Double Mode Compatibility : Supports both 2S (8.4V) and 3S (12.6V) battery packs with easy mode switching via solder jumpers and resistor adjustment . Efficient Fast Charging : Utilizes 15W synchronous boosting technology with 94% efficiency, Type C fast charging supported, and auto adjusting input voltages to reduce charging time . Adjustable Parameters : Customize charging current (0.5A 1.5A) via resistor replacement, set cutoff voltages per RVSET table, and configure timeouts protections (4 24 hours) for diverse battery types. Safety protections for input over/undered voltages, output over current/over voltages/short circuit, and optional temperature detection to prevent overcharging and overheating risks. Industrial Design : Measures just 31×15.1×4.5mm with double Type C/corded inputs and red/blue LED indicators for power/charging/error display, ideal for drones and portable energy storage. Specifications: Dimensions: 31x18mm/1.22x0.7in. Weight: 10g. Specifications: 2-string charging board, 3-string charging board (short circuit is recommended). for 1. Drones battery fast charging: for 2-string/3-string model aircraft and drones battery packs, greatly shortening the charging waiting time, 2. energy storage power supply: safely charging 3.7V polymer battery packs and achieve rapid energy replenishment 3. Power tool battery repair/charging: for electric hand drills, electric screwdrivers, car washers. Package Includes: 1PC Charging module note: Please allow 1-2cm errors due to manual measurement. Please allow for slight color differences due to different display resolution