I am still using my the Q Industries portable MV50 12VDC 150 PSI Air Compressor (AMAZON) I purchased back in the OFF-ROAD JEEP days.
It fits in its nice carry bag under my truck back seat. I usually sit this on my truck tailgate and hook into the trailer batteries and then I can use the provided long air coil hose to walk around the trailer and tires...
I also use this air compressor along with the CAMCO 36153 Blow Out Adaptor (AMAZON) to blow out my water lines for winterizing. Being TANKLESS it takes more time to build up air compressor which is ideal for blowing out water lines. This ADAPTER connects to the CITY WATER FILL PORT of the Trailer. This is great when camping in the high country and it gets down below freezing at night. I can blow out the water in the lines and add a small amount of of RV Antifreeze to the P-TRAPS. I can do this a quick five minutes time or and then refill the fresh water tank during the day when the temp gets above freezing..
Perfect setup for me and my OFF-ROAD POPUP trailer.
Roy Ken