DC backup power supply system

Abstract

A DC backup power supply system having a battery; a charge-discharge circuit for charging and discharging a power between the battery and a DC line; and a control circuit for controlling the charge-discharge circuit, wherein the battery has a number of battery cells and cylindrical portions of the battery cells are laid on an approximately horizontal plane.

What is claimed is:  
     
         1 . A DC backup power supply system comprising: 
 a battery;    a charge-discharge circuit for charging and discharging a power between said battery and a DC line; and    a control circuit for controlling said charge-discharge circuit,    wherein said battery has a number of battery cells and cylindrical portions of the battery cells are laid on an approximately horizontal plane.    
     
     
         2 . A DC backup power supply system comprising: 
 a battery;    a charge-discharge circuit for charging and discharging a power between said battery and a DC line; and    a control circuit for controlling said charge-discharge circuit,    wherein said battery has a number of battery cells, cylindrical portions of the battery cells are laid on an approximately horizontal plane, and a height of said battery is 45 mm or lower.    
     
     
         3 . A DC backup power supply system comprising: 
 a battery;    a charge-discharge circuit for charging and discharging a power between said battery and a DC line; and    a control circuit for controlling said charge-discharge circuit,    wherein said battery has a number of battery cells, cylindrical portions of the battery cells are laid on an approximately horizontal plane, and said battery is accommodated in a space having a height corresponding to one unit (1U) size of a 19-inch rack.    
     
     
         4 . A DC backup power supply system according to  claim 3 , wherein two DC backup power supply systems each having a rated output power of 700 W or larger are accommodated side by side in the space having the height corresponding to the one unit (1U) size.  
     
     
         5 . A DC backup power supply system according to  claim 1 , wherein said battery has 40 or more sub-C size nickel-metal-hydride battery cells.  
     
     
         6 . A DC backup power supply system according to  claim 5 , wherein the nickel-metal-hydride battery cells include two or more parallel connections of nickel-metal-hydride battery cells.  
     
     
         7 . A DC backup power supply system according to  claim 3 , wherein three DC backup power supply systems each having a rated output power of 400 W or larger are accommodated side by side in the space having the height corresponding to the one unit (1U) size.  
     
     
         8 . A DC backup power supply system according to  claim 7 , wherein said battery has 20 or more sub-C size nickel-metal-hydride battery cells.  
     
     
         9 . A DC backup power supply system according to  claim 1 , wherein if a full-charged voltage of said battery is 48 V or lower, a voltage at the DC line is set to 51 to 55 V.  
     
     
         10 . A DC backup power supply system according to  claim 4 , wherein the rated output power is supplied for 6 minutes or longer under the conditions that a temperature of said battery is 10° C. or higher, an internal impedance of said battery is twice or lower than an initial value and said battery is in a full-charged state.  
     
     
         11 . A DC backup power supply system comprising: 
 a battery;    a charge-discharge circuit for charging and discharging a power between said battery and a DC line; and    a control circuit for controlling said charge-discharge circuit,    wherein said battery has a number of battery cells, cylindrical portions of the battery cells are laid on an approximately horizontal plane, a plurality of DC backup power supply systems electrically connected in parallel are accommodated and juxtaposed in one rack, and the DC backup power supply systems have electric hot swap connections using connectors and cables.    
     
     
         12 . A DC backup power supply system according to  claim 1 , further comprising control means, when a power supplied from the DC line and consumed by a load exceeds a predetermined value, said control means activates the DC backup power supply system to supply a power to the load.