Review on Schumacher DC to AC Power Inverter - 410W Continuous, 820W Peak - Direct Battery Connection, 120V AC Outlet & USB Port by Alex Barnes

Does not work if the battery voltage is just under 13V. I have a load of 300 watts on it and at a voltage of 12.5V the red light flashes and the fan pumps. However, the alarm has not worked yet. I let it run the van cooler on the street to be powered by the truck's generator. There is no compressor in the fridge on wheels, so there are no power surges. It only works with constant voltage. The generator runs fine, but as soon as I stop I have to switch it to propane before the RV battery dies even a little or dies. This is not good for camping as the RV battery will drop below 13V quickly.