Sounds interesting. I know there are power users who would benefit. I have a customer who picked up the 2400 mAh batter at my suggestion and loves it, he can go all day with it compared to the OEM battery. So there most likely is a market, but weight and form factor will always be the bottom line concern.

__________________
My PDA & SmartPhone History: Palm Vx; M505;TungstenT; NX60; iPaq 1910; I700; Treo 600; hx4700; MPx220; hw6515, Treo 700w, XV6700,, Treo 700p, Moto Q Black, Moto Q9h, BlackBerry 8310 & BlackBerry 8820, BlackBerry Bold, BlackBerry Storm 9530.