Features 1.[Automatic Design] This battery charging control board is fully automatic and automatically charged and powered off, intelligent, efficient and safe. 2.[Adjustable Control] Both the battery start charging voltage and the disconnect charging voltage can be adjusted on the control board. 3.[Multi Function Use] In addition to being used as a charging and discharging module, it can also be used as a multimeter function. 4.[Use Application] The battery charging control board is suitable for charging batteries and batteries in all voltage ranges. 5.[Wide Application] With a wide range of application, controller module can be used in household chargers, solar energy, wind turbines, etc. Specification Item Type: Battery Charging Module Material: Plastic Product Model: HCW-M631 Input Voltage: DC 6-40V Voltage Error: ±0.1V Scope of Application: 6-40V Various Batteries Output Type: Relay Output Product Size: Approx. 66 x 46 x 16mm / 2.6 x 1.8 x 0.6in Hole Size: Approx. 3.3mm / 0.13in Package List 1 x Battery Charging Module