this is about the best chart i could find for the 044 without spending too much time digging:
i can't validate it without doing a full blown test on one so assume it is close to accurate. the test is done at 14 volts as per the picture title, at 10v the output would be about 25% lower but varies depending on the pump and its design and will drop more dramatically the more the voltage is reduced.
at 3 bar(43.5psi, 3.0X14.5) the 044 puts out just over 300 liters per hour@14v. using the same math conversions above it should drop down to roughly 4 minutes to fill the 5 gallon tank.
to wire the pump directly you should disconnect the pump connector and ground the ground wire to the chassis of the car and jump the power feed wire to the charging system(black/white wire). to test the voltage the pump is actually seeing wired to the car backprobe the black/white wire by stabbing it(reseal the puncture afterwards with liquid tape) and measuring the voltage with the key on.