Eaton 9170+ Battery Charger Module User's Guide 164201399 Rev Ewww.eaton.com/powerquality9Chapter 3 OperationThe Battery Charger Module operates in two automatic modes: As a charger module within the UPS cabinet under control of the UPSpower modules As an independent charger module located in an external batterycabinet containing battery modules for the UPS systemUPS Cabinet OperationWhen the Battery Charger Module is installed in the UPS cabinet, itcommunicates through a controller area network (CAN) bus with thepower modules. The power modules monitor and control the batterycharger. Alarm conditions detected by the Battery Charger Module arelogged and announced by the UPS system (refer to the UPS user'sguide). Normal output voltage is 133 Vdc.External Battery Cabinet OperationWhen the Battery Charger Module is installed in an external batterycabinet, it has no communication path with the UPS power modules.Therefore, it controls its own operation, independent of any systeminformation within the power modules.The module output current limit is set by the rear panel DIP switches.An audible alarm signals module status and alarm conditions (see“Troubleshooting” on page 21). Normal output voltage is 133 Vdc.Output FoldbackIf the Battery Charger Module senses a charged-battery condition, itfolds back its output voltage to prevent overcharging system batteries.Output current is controlled by power modules on the UPS CAN bus orby the rear panel DIP switches.