I've never been a fan of those tiny portable "plug in to your car's power point" type of inflators.. so I went a different route.
I already had a decent upright air compressor in my garage, so I just went to Harbor Freight and bought one of these:
If memory serves, it was only about $25 on sale.
I fill it up on my compressor at home, to about 95-100 PSI, and leave it in my trunk. I set up some magnets on the trunk liner and side, so the tank doesn't move when I'm driving.. just stays nice and snug in place until I need it, then a nice tug on it separates it from the magnets. 95PSI will easily pump up many low tires, and at least two flats.. and if it ever gets low, I just fill it back up at home. Never have to worry about whether my fuses will blow.