More sophistocated inverters may only draw a very nominal amount unless there is an actual load. Less sophisticated may draw more. Best to look at the specs of your specific Inverter.
My good old Freedom 20 has a configurable minimum load threshold. Below that load level it does not produce any output except a very low power
pulse to check for load. A few years ago someone working on my boat accidently left it on....for 6 months...no loads so no problem. Fine piece of gear
, going on 14 years old.
I do still turn mine on just as needed though to manage energy use, especially with guests aboard. The remote control panel
is at the nav station, next to my usual cabin
, which helps.