RE: battery duration
Pick a nice charger that cycles, etc.. I had a 1200mah nimh pack that was about 9 mos old. .recently it started showing 600 mah after full charge [>:] .. You'll never know whats going with your batteries with the standard wall wart type chargers. Please don't take this as gospel by any means but I think maybe the general rule is a typical 4 channel with standard flying.. nothing crazy pulls approx. 350mah per hour?? I would not extrapolate that to mean you could fly 3 hours. I think batteries lose approx 5% per day of the charge... and condition, storage, etc can affect that as well.
What type of batteries are you talking.. nicd or nimh. I beleive the nimh are less susceptible to memory issues but I cycle mine anyway.
Mike