portable tire inflators

I carry one by Goodyear. It will pump up to 150# and has been able to up the pressure in truck tires. Runs on the TV's 12v system. It's with me all the time.

Try a Viair 12V compressor (many models available on amazon). Available in a variety of CFM including some continuous duty models. Fairly well built and easy to run off of TT or TV batteries. Permanently mountable models are available as well.

I have used a bycycle pump which works fine but it is a bit of work! This past season I switched to a Harbour Freight 12V inflater. It has worked fine. It was very inexpensive, and I figure I've already gotten fair value out of it; every use going forward is a bonus.