System and method for monitoring and balancing voltage of individual battery cells within a battery pack

Abstract

Systems and methods for a scalable battery controller are disclosed. In one example, a circuit board coupled to a battery cell stack is designed to be configurable to monitor and balance battery cells of battery cell stacks that may vary depending on battery pack requirements. Further, the battery pack control module may configure software instructions in response to a voltage at a battery cell stack.

1 . A system for controlling monitoring and voltage balancing of individual battery cells within a battery pack supplying power to a vehicle, comprising:
 a circuit board; and   a controller including executable instructions stored in non-transitory memory to monitor and balance a first actual total number of battery circuits responsive to a first voltage across a voltage divider network and to monitor and balance a second actual total number of battery circuits responsive to a second voltage across the voltage divider network, and additional instructions to adjust a value of an index that directs the controller to sample specific battery cells of a battery cell stack within the battery pack responsive to the first voltage when the first voltage indicates an actual number of populated circuits of the circuit board.   
     
     
         2 . The system of  claim 1 , further comprising additional instructions to adjust the value of the index that directs the controller to sample specific battery cells of a battery cell stack within the battery pack responsive to the second voltage when the second voltage indicates the actual number of populated circuits of the circuit board. 
     
     
         3 . The system of  claim 1 , wherein the voltage divider network is comprised of a first and a second resistor included with the circuit board, said first and second resistors connected in series between a first reference and a second reference, said first resistor and said second resistor sized to produce a unique voltage representing an actual total number of populated monitoring circuits and voltage balancing circuits included in the circuit board. 
     
     
         4 . The system of  claim 1 , wherein the circuit board is a battery cell monitoring and balancing board that includes a power supply that is powered via battery cells within the battery pack. 
     
     
         5 . The system of  claim 4 , further comprising a battery control module that includes selectively activates the power supply. 
     
     
         6 . The system of  claim 1 , further comprising additional executable instructions to compare the first voltage and the second voltage to a map of monitoring and balancing board configurations. 
     
     
         7 . A system for controlling monitoring and voltage balancing of individual battery cells within a battery pack supplying power to a vehicle, comprising:
 a circuit board comprising a plurality of monitoring circuits and balancing circuits, the circuit board electrically coupled to a plurality of battery cells external to the circuit board;   a first and a second resistor included with the circuit board, said first and second resistors connected in series between a first reference and a second reference, said first resistor and said second resistor sized to produce a unique voltage representing an actual total number of populated monitoring circuits and voltage balancing circuits included in the circuit board; and   a controller including executable instructions stored in non-transitory memory to sample one or more battery cells responsive to the unique voltage.   
     
     
         8 . The system of  claim 7 , further comprising additional instructions to adjust a value of an index that directs the controller to sample specific battery cells of a battery cell stack within the battery pack responsive to the unique voltage. 
     
     
         9 . The system of  claim 7 , wherein a power supply of the circuit board provides the first reference. 
     
     
         10 . The system of  claim 9 , wherein the power supply is supplied power via battery cells in the battery pack. 
     
     
         11 . The system of  claim 10 , wherein the power supply draws a constant amount of current from the battery cells. 
     
     
         12 . The system of  claim 9 , further comprising additional instructions to activate the power supply via a battery control module, the battery control module separate from the circuit board. 
     
     
         13 . The system of  claim 7 , further comprising zero ohm resistors and jumpers connecting depopulated circuits to populated circuits. 
     
     
         14 . A method for monitoring and voltage balancing a battery cell stack, said battery cell stack comprising a plurality of battery cells, an actual total number of said battery cells varying between different battery cell stacks, the method comprising:
 populating an actual total number of monitoring and voltage balancing circuits on a circuit board up to N monitoring and voltage balancing circuits, where N is a maximum number of battery cells arranged in series, said actual total number of monitoring and voltage balancing circuits varying between a first number of circuits and a second number of circuits, said circuit board electrically coupled to said plurality of battery cells external to said circuit board, and not populating at least one monitoring and voltage balancing circuit from said circuit board when less than N battery cells are monitored;   populating a resistor network on said circuit board with resistors based on said actual total number of populated monitoring and voltage balancing circuits on said circuit board; and   coupling a power supply in parallel with said plurality of battery cells, the power supply discharging the plurality of battery cells, the power supply also coupled to the resistor network.   
     
     
         15 . The method of  claim 14 , further comprising sampling an actual total number of battery cells responsive to a voltage output from the resistor network. 
     
     
         16 . The method of  claim 15 , further comprising adjusting a value of an index that directs a controller to sample specific battery cells of the battery cell stack responsive to the voltage output from the resistor network. 
     
     
         17 . The method of  claim 16 , further comprising comparing the voltage output from the resistor network to a map of monitoring and balancing board configurations. 
     
     
         18 . The method of  claim 14 , wherein the voltage balancing circuits are configured to reduce charge or battery cells. 
     
     
         19 . The method of  claim 14 , wherein said power supply is activated via a battery control module. 
     
     
         20 . The method of  claim 14 , further comprising sampling a battery cell via an analog to digital converter responsive to a voltage output of the resistor network.