A. In their normal position, the FloodStop valves are open and will allow water to pass through; once water touches their sensor, the motorized ball valve is tripped and the valves are closed. The valve(s) will remain closed until the sensors are dried and the reset "Open" button is pressed. The Controller has a battery port for 4 X AA size batteries, which will serve as a battery backup in case of a power outage. The same batteries will serve as the primary power source if a nearby electrical outlet is not available (battery life 1 year).