In a storage-battery control system, an insulating communication unit couples a controller and a plurality of battery modules coupled together in series to configure a storage battery unit. A floating grounding pattern of the controller is divided into a first floating grounding pattern and a second floating grounding pattern. The plurality of battery modules in the storage battery unit is divided into a first zone battery module group and a second zone battery module group so that the battery modules belonging to the first zone battery module group correspond to the first floating grounding pattern, while the battery modules belonging to the second zone battery module group correspond to the second floating grounding pattern. An insulating communication unit couples the respective battery modules.