I can attest to this and multiple batteries while unit getting pretty hawt but very impressive nonetheless!I've got the milwaukee m18, I've been very happy with it. I've been surprised how many tires one battery will air up.
Did use it in an emergency to air up a tire on semi's grain trailer out in the field. From completely flat to 105lbs of air in a semi tire did take two batteries and a long time but it got it aired up. I wouldn't recommend using it for semi tires but it will do it.