Well, I rode yesterday starting cold, and it still wouldn't go above 13V.
Just got an email back from Service Honda... the parts department apparently doesn't know anything about an upgrade kit.
Go back to page 1 of this thread and the second post down is a link to Mike Martin's page, on that page click on John's list of parts. All the parts and part numbers are listed for you. You just have to pick between an OEM or aftermarket fuse block. Good Luck!!