Without a compensating device, you may also consider select a more aggressive throttle curve at some time into the flight.

From this discharge curve for 5000mah (http://www.rcgroups.com/forums/attac...mentid=6727159), it seems such a time is at 0.5ah. Hard to translate that point into time into the flight without telemetry. But my guess would be after turnaround and right before entering the box.