Uninterruptable power supply system and method

An uninterruptable power supply (UPS) system/method providing power line conditioning and power factor correction (PFC) that incorporates centralized battery backup energy storage architecture is disclosed. The system generally comprises an AC-DC power supply with active PFC (power factor correction) function, a battery transfer switch, an isolated battery charger placed between the utility power source and battery strings, battery strings connecting the battery charger and the battery transfer switch, EMI/Lightning circuitry that provides lighting/line surge protection as well noise suppression functions, and a controller monitoring the quality of the utility power source. Uninterruptable power for data centers is achieved in this context via use of the battery strings, battery transfer switch, battery charger, and controller system configuration. Disclosed methods associated with this system generally permit the UPS to operate in a distributed fashion in support of computing systems within data centers.