Using the 41 amp version

Then full throttle will draw 41000 mah an hour

(41 amp * 1000 ) = 41000 mah / 20c = 2050

So a 2050 pack would last at 85% capacity utilization

(2050 * .85) / 41000 hours

or .0425 hours * 60 minutes = 2.55 minutes

and your battery will hate you...

Under normal sport flying I would anticipate a time of around 7 minutes would be safe