XC Dawg said:
These are the rechargeable lights, the battery I'm talking about is close to the size of a water bottle and attaches to my top tube.......I seriously doubt radioshack will have anything like that but thanks for the feedback
Those are the 6V Gel Cells, Vista originally used Hawker Cyclone cells, which have very good deep discharge capabilities, but are hard to get, You can replace them with the standard 6V Gell cells (4 ~ 5AH versions in sizes that fit the bag) available from electronic or some surplus stores, anywhere from $5 to $25. I picked up a 5AH version for $11 two weeks ago. You may have to re-solder the wires on.
As AppMTB said, you can replace them with NiMH batteries, or any 6V battery with a 4~5AH rating. However, your existing charger (if it is OEM) only works with the gel cells, so unless you want to buy a new charger, I would suggest you get a replacement Gel Cell - besides, they are cheaper.