You may be better off building your own battery pack, I did. inside mine is an 18AH battery about the size of a motorbike battery.
It will last all weekend running my LED lights, I decent battery pack with different outlets cig,merit and Anderson should set you back around $100.
or buy a plain one and fit all plugs etc yourself
EDIT::::: must fit a USB port to it in the future, already have one inside the Patrol