The VSR connects and disconnects the auxiliary battery and starts the battery while the engine is running according to the current charge level. When the starting battery reaches 13.2 volts, the VSR start after 15 seconds and the LED light up. This means that both batteries are connected and the system is running. Once the vehicle system is turned off, the two batteries be disconnected when 12.8 volts is reached after another 15 seconds, allowing your main battery to restart safely. Name: Intelligent dual battery controller Voltage: 12V Maximum operating current: 50A current: 70A Current consumption - charging: 150MA Current Consumption - Standby: 1.5MA Insertion voltage: 13.2V Cut off voltage: 12.8V Breakaway Delay: 15 seconds Protection level: water protection Applicable: Cars, motorcycles, go-karts, ATVs, etc. Colour:black Material:ABS Package Contents: 1x Dual Battery Isolator Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.