As predicted by some of you I cannot run my 20 inch box fan on high or medium for more than a few minutes before the low voltage alarm sounds. It seems to work on low for several hours. So as suggested I need to connect directly to the battery. The factory inverter DC cord is kind of a specialty cord to this unit as there are two pins that plug into the inverter from a cigarette lighter style plug. Cannot locate a specif cord with clips for my battery that has the two pins. So should I cut off the cig lighter end and straight wire to battery? Power will still go through the factory cord. Any thoughts?