Regarding what we use our Power Inverter for...
We camp out alot off-grid here along the Blue Ridge Mtns and in the George Washington Natl Forest along the wooded Virginia/West Virginia winding state line.
Just about all of our small wattage items that I like to run are 120vAC from a small PSW Power Inverter... I probably could make up ways to use just 12VDC but it sure is convenient just to have a couple of what I call EMERGENCY POWER MULTIHEAD PSW 120VAC Drops in both ends of my off-road POPUP. Then you can safely just plug in anything you got to the 120vAC available there...
I have what I call my duty 600WATT AIMS PSW Power Inverter (AMAZON) which is always ON and when we are camping off-grid I normally just pull around 20AMPS or so which relates to around 250WATTS or so from the 600WATT Power Inverter connected to my 12VDC battery bank.
Roy Ken