The ABB PowerValue 11 RT 6-10kVA External Battery Module is a required add-on for the PowerValue 6-10 kVA UPS as it does not have internal batteries. 

PowerValue External Battery Modules (EBM) allow you to extend the runtime of ABB PowerValue UPS systems. Up to 4 EBMs can be attached to a UPS and the chart below demonstrates the extended runtime in minutes depending on the load being supplied.