Portable air compressor plugs into cigarette lighter

I installed a 12-volt outlet in a central bay on each side of my coach so I can reach all of the tires and the water bay with my 12-volt "TruckAir" compressor. I picked up the power from the 15 amp bay lighting circuit. I blow out the water lines by pressurizing the system, including the water heater and accumulator tank, to about 50 PSI before bleeding it off at the faucets and drains. Two or three recharges and the job is done.