Large Scale Battery Systems and Method of Assembly

Abstract

The methods in this disclosure allow for the identification, selection, and arrangement of cells, blocks, and modules in large scale battery systems, such as electric vehicle battery systems. An example embodiment of the present invention allows for the identification of the cells, blocks, and modules with a unique identifier or associated parameter (e.g., internal resistance contributions or capacity). Additionally, to form a block, cells may be selected from a group of capacity-range sorting bins. Based on a parameter of the cell, a pseudo-number generator may be also be used to select cells from an available inventory of cells as maintained in a cell database based. Cells may also be placed in a block for uniform effective cell impedance and even cell aging while minimizing overall block capacity degradation caused by cycling. Block capacities may also be computed based on a known average temperature gradient during operation.

What is claimed is: 
     
         1 . A method of selecting cells for a battery system, comprising:
 measuring internal resistance for components of the battery system;   maintaining a database that includes internal resistance measurements; and   placing cells in the battery system based on the internal resistance measurements.   
     
     
         2 . The method as claimed in  claim 1 , wherein placing cells includes placing cells having a low internal resistance measurement in areas of high internal resistance contributed from other components of the battery system relative to battery terminals. 
     
     
         3 . The method as claimed in  claim 1 , wherein placing cells includes placing cells having a high internal resistance measurement in areas of low internal resistance contributed from other components of the battery system relative to battery terminals. 
     
     
         4 . The method as claimed in  claim 1 , wherein the database includes identification designations and associated parameters, including the internal resistances, for the cells and components of the battery system. 
     
     
         5 . The method as claimed in  claim 1 , wherein the associated parameters include capacities of the cells and components of the battery system. 
     
     
         6 . A battery system comprising:
 a plurality of electrically coupled blocks of plural battery cells, including parallel connected battery cells within each block; and   in each block, battery cells having a low internal resistance are placed in areas of high internal resistance contributed from other components of the battery system relative to battery terminals.   
     
     
         7 . The battery system as claimed in  claim 6 , wherein, in each block, battery cells having a high internal resistance are placed in areas of low internal resistance contributed from other components of the battery system relative to battery terminals. 
     
     
         8 . A method of selecting desired capacities for components of a battery system, comprising:
 determining a temperature profile within the battery system;   estimating a temperature dependent capacity of components of the battery system; and   selecting components of the battery system using the temperature dependent capacities and temperature profile.   
     
     
         9 . The method as claimed in  claim 8 , further comprising:
 selecting a reference block to establish an acceptable temperature for blocks within the battery system;   determining a temperature differential based on the reference block temperature and temperature of other blocks within the battery system;   determining desired capacity of blocks within the battery system based on the temperature dependent capacities and temperature differential; and   placing blocks within the battery system based on the calculated desired capacity.   
     
     
         10 . A battery system comprising:
 a plurality of electrically coupled battery system components; and   battery system components having low capacity are selected to be placed farthest away from a heat source.   
     
     
         11 . The battery system as claimed in  claim 10 , wherein the battery components include a plurality of electrically coupled blocks of battery cells. 
     
     
         12 . The battery system as claimed in  claim 10 , wherein the battery components include a plurality of electrically coupled modules of blocks of battery cells.