Just wire in an ~18v power supply, or, better yet, solder on a female connector for one if you can. As Tim has mentioned before, the heater band, PID controller, and fans are capable of 18v operation. (The stall board just shaves it down to 12v)
Filastruder 2607 w/ Filawinder @1.75mm.
Dual-extruder MaxMicron Prusa Mendel: RAMPS 1.4 w/ Repetier Firmware+Full Graphic LCD Controller, stock hotends, 3Dator extruders w/ MK8 gears, insulated enclosure w/ 2 heat lamps, RPi 2B w/ Repetier Server.
0.1-0.2mm layer height, heated bed w/ PEI surface, inductive-sensor autolevel, 0.5mm to 0.2mm nozzle diameters.