Part number 5812116, 2001-2004
Item 18 in the diagram, about 4 by 7 inches

Also used in the 1996-2000 models as part number 5850136. I have no idea what the difference between the two part numbers is

This pad sits under the battery, and protects the battery from concentrated pressure spots from the molded hull supports.

My Virage TXi battery pad has gone missing, and my battery bottom is showing signs of not being happy about it

I know I could make a couple up from some material, but if someone has the battery pad from a parted out Virage, Freedom or Octane, let me know.