Larger capacity batteries are available,but I would not want the extra weight of 2 batteries plus the hardware used to mount it. Yes I know, velcro is a possibility here, but 2 batteries = twice the problems.I tried a 8000 aftermarket battery and an external adaptor a few years ago and the q500+ took of on me. We found it unharmed in a corn fiel 3 month's later.I gave the farmer a nice reward! Peace KC