LeftieBiker wrote: ↑
Sat Nov 30, 2019 5:49 pm
Remember, Al, that when you multiply the voltage from 12 to 120 with an inverter, the amps drawn by the inverter are ten times the amps drawn by the 120 volt devices. So 50 watts at 120 is 500 watts (plus losses) drawn by the inverter from the car.
Watts are the same at 12 or 120 volts (ignoring inverter losses) so input current at 12 volts is 10 times output current at 120 volts. Do not try to draw more than 120 watts from the 12-volt power socket. Larger inverters should be connected directly to the 12-volt battery.
Edited to fix typos. Thanks to LeftieBiker for correcting his post.
Since my new car has plenty of battery capacity, I plan to set up a 2 kW sine wave inverter with heavy duty jumper cables to connect only when needed. I plan to make up custom cables with fuses near the battery clips (jumper cable clamps) and appropriate connections to the inverter input.