Patent ID: 8097978

Claim:
A system for extending backup times using networks of direct current (DC) uninterruptible power supplies (UPS), comprising: a power supply; a first load; a second load; a first DC UPS comprising a first power input, a second power input coupled to the power supply, a first power output, and a second power output coupled to the first load; and a second DC UPS comprising a third power input coupled to the power supply, a fourth power input coupled to the first power output, a third power output coupled to the second load, and a fourth power output coupled to the first power input and configured to supply power to the first DC UPS via the first power input, wherein: the first power output is configured to supply power to the second DC UPS via the fourth power input, power from the first DC UPS is shared with the second load in the event the power supply becomes unavailable, and power from the second DC UPS is shared with the first load in the event the power supply becomes unavailable.