The FT817ND has 2 options for on board power. Using the NMH battery pack (9.6 v) yields 2 to 3 hours operating time.
Using the alkaline battery tray is yet to be determined. Alkaline batteries appear designed with a 1.5v output, so 8 cells yield (12v) output.
I hope to test/check today operating portable and get an idea for the operating time from the alks. Im not sure why rechargable cells have a lower design voltage.
fresh batteries today yielded normal operation from the rig today. I worked a station in NC from a portable location near Vandalia, OH. I will be set to operate portable and from various summits along the BR Parkway later next week.