Imagine the insanity of semi-truck or motor-home out on the road for weeks at a time without an ac power supply to run your electronics. That is why dc to ac power inverters are found in every truck and RV so you do not have to deal with being unplugged. Inverters use a dc power supply from a car battery and invert the current into a ac power supply.
How inverters work?
Alternating current changes its polarity 60 times per second (HZ) send power through the circuit one way and reversing another therefore it can hold a high 120 volt output. Direct current is more simple only sending power in one direction, which is ideal at low voltage outputs. Because of the nonflexable current it will not function properly at higher voltages that U.S. electrical systems require. Inverters take a dc power supply and increase the output voltage with the use of a step up transformer to properly run your devices.