I never bought the battery powered pumps. I went to Radio Shack and picked up a plug converter that runs from the cig lighter in the car. That way I can use the air pumps I have already. I think it only ran about $8..
when my family and i was moving we had to move 13 koi's ranging from 4-20 inches. my dad went to walmart and bought a few plastic storage bins and bought some battery operated air pumps. the trip was about an hour and a half to two.