I ran my windlass on the house side, but there were some unintended consequences. These DC motors are pretty "dirty" , like starter motors. I cringed when the windlass turned on and the chartplotter went into reset mode. The wiring was large enough, but the surge was not handled well.
If I were to do it again, I would have no issue using a engine start battery, and if the wiring run was too long, then it would be a dedicated battery. The savings in copper wire alone could easily pay for the battery.