I carry the Harbor Freight oil less 100 psi pancake compressor that costs between $40-$60 depending on which sale. It is very light, easy to put in a far corner of the storage area out of the way. It has a standard quick disconnect. Then buy a cheap coiled hose and a filler end with a built in gauge, It will do the tires on the RV (82psi) no problem, including the inside duals with no extensions.
Slow, and noisy, compared to a shop compressor, but how often do I need it? Pluses are that it can be run off the small inverter anytime on the road, and you can lift it at arm's length easily. I try to go lightweight on items that are infrequently used. Apparently, it all adds up!