KnowUPS - DC Battery Architecture

I was talking with a customer this week about extended run battery packs and realized that one spec that is never really highlighted is the DC battery voltage.   While normally meaningless, its is very important in extended run battery cabinets.  This is because when you connect extra batteries, it must match the internal battery voltage to properly be paralleled in    To prevent catastrophe, each UPS maker creates stupid little plugs that prevent you from plugging the wrong voltage in.

Common string DC voltages range from 24volt to 240volt... here are some guides

• 24 volt = APC 1000va and under (SUA1000XL / 110b)
• 48 volt = APC 2nd -4th Gen units (SUA3000RMXL3U / 333b),  Eaton/Liebert/HP 1.5-2.0kva units (GXT2000XT120 / lg212), Tripplites (SMART2200RT2U // tl312), 5th Gen APC 1500va (SMX1500RT2U / 412v)
• 72 volt =  Tripplites  (SU3000RTXL3U / to313) and Liebert 3000va systems (PS3000RT3-120XR / lp312)
• 120 volt = HP (R3000XR / hp312), Eaton 3kva units (P5392v), Symmetra
• 144 volt = Liebert 6000va (GXT2-6000RT208v)
• 192 volt = APC Smart UPS RT (SURTD5000XLT / 593g4)
• 240 volt = Liebert 10kva, Eaton 6kva, Tripplite 5000va SmartOnline (to595)