I tested receiver battery packs after 6, 7, and 8 ten minute flights. 6 flights was easily obtainable and after the 8th flight the batteries were pretty much at the lower safety limit. This was using 500 or 600 mah. packs. If you have a 1500 or 1600 mah pack, then of course you can pretty much double that but then you better be watching the transmitter batteries as well. [8D]