How long does it take to fill your tank?

I got problems all the time with my air supply not being able to keep up with my air demand. I run 2 blitzlift 337 in a 7 gallon tank. Half inch valves and lines one time up competely sucks my psi from 145 to 110, second time up 110 to 70. Anyways it takes my 2 compressors about 2 minutes to fill me from 110 to 145. Seems pretty slow i thought for having 2 compressors. How long does it take you to fill your tank?