Methods and system for redox flow battery idle state

A redox flow battery system, comprising:

• a power module comprising a plurality of redox flow battery cell stacks, each of the plurality of redox flow battery cell stacks comprising a redox flow battery cell;
• an electrolyte pump capable of delivering electrolyte from an electrolyte tank to the power module;
• and
• a power control system with a controller storing executable instructions in non-transitory memory, the instructions executable to:
• switch the redox flow battery system to an idle mode, wherein the idle mode includes operation of the redox flow battery system outside of a charging mode and outside of a discharging mode;
• initiate an off cycle timer and a drain timer concurrently;
• activate the electrolyte pump while the redox flow battery system is in the idle mode to circulate electrolyte through one or more electrode compartments of the redox flow battery system when an off cycle threshold period of time monitored by the off cycle timer elapses;
• deactivate the electrolyte pump while the redox flow battery system is in the idle mode when an on cycle threshold period of time monitored by an on cycle timer elapses, the on cycle timer initiated when the off cycle threshold period of time elapses;
• and
• responsive to elapsing of a drain threshold period of time monitored by the drain timer while the redox flow battery system is still in the idle mode,
• completely drain the electrolyte from the one or more electrode compartments of the redox flow battery system while the redox flow battery system in in the idle mode;
• purge the drained one or more electrode compartments with a gas;
• and
• refill the purged and drained one or more electrode compartments with fresh electrolyte;
• wherein the drain threshold period of time is longer than the off cycle threshold period of time.