The Project Farm guy just did a review of portable tire pumps two weeks ago. His top three picks are linked below.
There are tradeoffs with all of them. None of these are as fast as a good quality pancake air compressor, but they are much more portable. A big question is what your use case is. Do you need to add a bit of air when the temperature drops, and keep some bike tires inflated, or are you mounting your own snow tires, and need to fill them from flat?
For adding a few pounds, and small tires, the battery powered portable ones can be very convenient, and being slow isn’t an issue. If you routinely have to fill car tires from flat, then get a big compressor.
