Storage battery pack and method of operating the same

Abstract

A battery charging system includes: terminals charging or discharging a secondary battery; a circuit including a power consumer consuming power of the battery; a switch controlling current flow from the battery; a controller; and a memory. The memory includes various instructions instructing the controller to: activate the circuit and cause the power consumer to consume a remaining power of the battery until the battery voltage reaches a first threshold higher than a discharge cutoff voltage; stop, when the battery voltage reaches the first threshold, a first discharge operation; supplying power to an external device; stopping, when the voltage of the battery reaches the discharge cutoff voltage, the power supply operation by controlling the switch; and receiving power, for charging the battery, from an external power supply until the voltage of the battery reaches an upper limit.

What is claimed is: 
     
         1 . A battery charging system comprising:
 terminals for charging to or discharging from a secondary battery of a storage battery pack;   a circuit that includes a power consumer which consumes power of the secondary battery;   a switching element that controls current flow from the secondary battery;   a controller; and   a memory including a set of executable instructions that, when executed by the controller causes the controller to perform a first discharge operation including:
 activating the circuit and causing the power consumer to consume a remaining power of the secondary battery until a voltage of the secondary battery reaches a first threshold value which is higher than a discharge cutoff voltage; and 
 stopping, when the voltage of the secondary battery reaches the first threshold value, the first discharge operation, 
   the memory also including a set of executable instructions that, when executed by the controller causes the controller to perform a power supply operation including:
 supplying power to an external device; and 
 stopping, when the voltage of the secondary battery reaches the discharge cutoff voltage, the power supply operation by controlling the switching element, 
   the memory also including a set of executable instructions that, when executed by the controller causes the controller to perform a charging operation including:
 receiving power, for charging the secondary battery, from an external power supply until the voltage of the secondary battery reaches an upper limit. 
   
     
     
         2 . The battery charging system according to  claim 1 , wherein
 the controller performs the first discharge operation under a condition that the voltage of the secondary battery is lower than a second threshold value which is higher than the first threshold value.   
     
     
         3 . The battery charging system according to  claim 1 , wherein
 after the stopping the first discharge operation, the controller automatically starts the charging operation to charge the secondary battery.   
     
     
         4 . The battery charging system according to  claim 1 , further comprising
 a communicator that allows communication with an external entity,   wherein,
 the controller performs the first discharge operation when the communicator receives a command, which requests to perform the first discharge operation, from the external entity via wireless communication. 
   
     
     
         5 . The battery charging system according to  claim 2 , wherein
 after stopping the first discharge operation, the controller automatically starts the charging operation to charge the secondary battery.   
     
     
         6 . The battery charging system according to  claim 1 , wherein
 the controller performs the first discharge operation under a condition that
 (i) the voltage of the secondary battery is lower than a second threshold value which is higher than the first threshold value, and 
 (ii) a predetermined period has elapsed since a last first discharge which has been performed. 
   
     
     
         7 . The battery charging system according to  claim 1 , further comprises:
 a communicator that allows communication with an external entity,   wherein,   the memory including a set of executable instructions that, when executed by the controller, causes the controller to perform operations including:
 transmitting state information indicating a remaining capacity of the secondary battery to the external entity via the communicator. 
   
     
     
         8 . The battery charging system according to  claim 1 , further comprises:
 a communicator that allows communication with an external entity,   wherein,   the memory including a set of executable instructions that, when executed by the controller, causes the controller to perform operations including:
 receiving information, via the communicator, indicating command to check a remaining capacity of the secondary battery from the external entity, and 
 transmitting, in response for the command, state information indicating the remaining capacity of the secondary battery to the external entity via the communicator. 
   
     
     
         9 . The battery charging system according to  claim 1 , wherein,
 the memory including a set of executable instructions that, when executed by the controller, causes the controller to perform operations including:
 detecting a signal indicating a start of charge, 
   the controller performs, when the signal indicating the start of charge is detected, the first discharge operation under a condition that the voltage of the secondary battery is lower than a second threshold value which is higher than the first threshold value.   
     
     
         10 . The battery charging system according to  claim 1 , wherein
 the memory including a set of executable instructions that, when executed by the controller causes the controller to perform a second discharge operation including:
 activating the circuit and causing the power consumer to consume the remaining power of the secondary battery until the voltage of the secondary battery reaches a third threshold value which is lower than the discharge cutoff voltage. 
   
     
     
         11 . A battery management method for controlling a secondary battery, the battery management method comprising:
 performing a first discharge operation, for learning discharge of the secondary battery, under a condition that:
 (i) a voltage of the secondary battery is higher than a first threshold value which is higher than a discharge cutoff voltage of the secondary battery; and 
 (ii) the voltage of the secondary battery is lower than a second threshold value which is higher than the first threshold value, 
   wherein, the first discharge operation includes:
 consuming a remaining power of the secondary battery until the voltage of the secondary battery reaches the first threshold value; and 
 stopping, when the voltage of the secondary battery reaches the first threshold value, the first discharge operation, 
   performing a power supply operation including:
 supplying power to an external device; and 
 stopping, when the voltage of the secondary battery reaches the discharge cutoff voltage, the power supply operation by controlling the switching element, 
   performing a charging operation including:
 charging the secondary battery, from an external power supply until the voltage of the secondary battery reaches an upper limit. 
   
     
     
         12 . The battery management method according to  claim 11 , further comprising:
 after the stopping the first discharge operation, automatically starting the charging operation to charge the secondary battery.   
     
     
         13 . The battery management method according to  claim 11 , further comprising:
 transmitting state information indicating a remaining capacity of the secondary battery to the external entity via a communicator of the storage battery pack.   
     
     
         14 . The battery management method according to  claim 11 , further comprising:
 displaying, on a display of the external entity, a remaining capacity of the secondary battery based on the state information.   
     
     
         15 . The battery management method according to  claim 11 , further comprising:
 receiving information, via a communicator of the storage battery pack, indicating the command for causing the storage battery pack to perform the second discharge operation from the external entity.   
     
     
         16 . The battery management method according to  claim 11 , further comprising:
 recording information indicating the history of the first discharge operation.