crybaby 535Q 18v install roadrage board or buy power plug?

[snz728]

Bought an older crybaby 535Q for $20 to build a weener wah.  Turns out the pedal sounds ok after i cleaned out all the cat hair.  Its the older version with two batteries that runs at 18 volts.

could I install a roadrage board to run it at 18volts (should be easy right?)

or

leave it like it is and buy an 18 volt adapter?

any advice would be helpful