Mine did an hour and half on the water yesterday with a standard 385 brushed. It was windy, so I needed a little more power on than usually necessary simply for the rudder to overcome the weather cocking effect of the wind. When I recharged the (3300mAh) battery, there was at least another half hour's worth of charge left, so I reckon your two together should give you six hours on the water, probably more as your motor will be more efficient than mine. It's a pleasant boat to sail, but six hours….