Fault Codes/Rehlko/BATTERYBACKUPLOWRehlkoBATTERYBACKUPLOWUnclassifiedElectricalWhat This Code MeansBATTERYBACKUPLOWPossible Causes•Transfer switch controller battery voltage is lowSuggested Actions1Replace batteryRelated Rehlko Fault CodesBCFBUSDEADLIVEBATTERY VOLTAGE LOW WCFGMODELNUMBATTERY VOLTAGE HIGH WCFGSYSVOLTBATTERY LOW WARNINGCHECK AC SENS LOSSBATTERY HIGH WARNINGCONCHECKFAILBATTERY HIGHCONNOTDETERMBrowse all Rehlko fault codes→ASK RUDY ABOUT THIS FAULTGet a diagnosis walkthrough for BATTERYBACKUPLOW on your specific Rehlko unit — cited to the OEM manual, not a forum guess.Your question about BATTERYBACKUPLOWGET THE ANSWERFree account required — we'll bring your question with you.