The maximum charge current is a total of 16A. Two batteries with a maximum of 8A each or 1 battery can be connected in parallel to both outputs up to a maximum of 16A. If you are connecting only one battery, it must be connected to connection 2. There are 3 LED lights, one to show that battery one is charging, one to show that battery two is charging and one to show that both batteries are fully charged. An F16A fuse is required, but not supplied.