A dialysis system (10a, 20) is described. The system comprises: a water purification unit (22); a dialysate generation unit (24) configured to use water purified by the water purification unit; a dialysate delivery unit (30) configured to deliver dialysate prepared by the dialysate generation unit; a supplemental power source (14); and electrical circuitry configured such that a branch power source (12) and the supplemental power source share a power load required by the water purification unit, the dialysate generation unit and the dialysate delivery unit.