System and method for establishing connections of a battery module
A battery module includes a housing and battery cells disposed in the housing, each of the battery cells including two terminals. The battery module also includes bus bar cell interconnects including a first material, where each bus bar cell interconnect is configured to electrically couple two adjacent battery cells via an electrical coupling with a first terminal of one of the adjacent battery cells and a second terminal of the other adjacent battery cell, where at least one of the first and second terminals includes the first material. The battery module includes welds, each weld being disposed at a corresponding welding point to directly couple one of the bus bar cell interconnects with the corresponding at least one terminal including the first material. Each welding point is accessible for welding from a position above the battery cells when the interconnects are disposed over the battery cells.
1. A battery module, comprising:
a first battery cell comprising a first terminal;
a second battery cell adjacent to the first battery cell, the second battery cell comprising a second terminal;
a bus bar cell interconnect coupled to the first terminal of the first battery cell and the second terminal of the second battery cell, wherein a body of the bus bar cell interconnect is fabricated from a first metallic material and wherein the bus bar cell interconnect comprises a welding surface that comprises a metal piece fabricated from a second metallic material different from the first metallic material;
a printed circuit board comprising a voltage sense terminal; and
a wire bonded connection fabricated from the second metallic material, and comprising a wire welded to the welding surface of the bus bar cell interconnect and electrically coupled to the voltage sense terminal of the printed circuit board.
2. The battery module of claim 1 , wherein the wire is welded to the voltage sense terminal.
3. The battery module of claim 1 , wherein the wire bonded connection comprises a trace in the printed circuit board, and the wire is welded to the trace.
4. The battery module of claim 1 , wherein the first second metallic material comprises copper, aluminum, tin, or any combination thereof.
5. The battery module of claim 1 , wherein the wire bonded connection has a curved shape that follows a profile of the printed circuit board and of the bus bar cell interconnect.
6. The battery module of claim 1 , wherein the voltage sense terminal comprises a voltage sense connection tab mounted on the printed circuit board, and wherein the wire is welded to the voltage sense connection tab.
7. The battery module of claim 1 , wherein the bus bar cell interconnect comprises:
a first segment connected to the first terminal of the first battery cell, wherein the first segment and the first terminal comprises the second metallic material and the first segment comprises the metal piece; and
a second segment linked to the first segment, and connected to the second terminal of the second battery cell, wherein the second segment and the second terminal comprises the first metallic material.
8. The battery module of claim 7 , wherein the second metallic material is aluminum and the first metallic material is copper.
9. A battery module, comprising:
a lid assembly comprising a plurality of bus bar cell interconnects, wherein each bus bar cell interconnect is configured to couple two battery terminals;
a printed circuit board (PCB) comprising a plurality of voltage sense terminals; and
a plurality of wire bonded connections configured to electrically couple each voltage sense terminal of the plurality of voltage sense terminals to a respective bus bar cell interconnect of the plurality of bus bar cell interconnects, wherein the plurality of wire bonded connections is fabricated from a first metallic material, the plurality of bus bar cell interconnects are formed from a second material different from the first metallic material, and wherein each respective bus bar cell interconnect comprises a respective welding surface for attachment of a respective wire bonded connection, wherein the respective welding surface comprises a respective metal portion fabricated from the first metallic material.
10. The battery module of claim 9 , wherein each respective wire bonded connection is configured to conduct a first current between the respective bus bar cell interconnect coupled to the respective wire bonded connection and a respective voltage sense terminal coupled to the respective wire bonded connection that is substantially lower than a second current conducted by the respective bus bar cell interconnect between respective two battery terminals coupled to the respective bus bar cell interconnect.
11. The battery module of claim 9 , wherein each respective bus bar interconnect is coupled to a voltage sensor of the PCB by a respective voltage sense terminal and a respective wire bonded connection.
12. The battery module of claim 11 , wherein the printed circuit board comprises a contactor relay control circuit that receives a signal from the voltage sensor of the PCB.
13. The battery module of claim 11 , wherein the printed circuit board comprises a pre-charge circuit configured to receive a signal from the voltage sensor of the PCB.
14. The battery module of claim 9 , wherein at least one bus bar cell interconnect is a bus bar link, and wherein the respective wire bonded connection is welded to the bus bar link.
15. The battery module of claim 9 , wherein at least one bus bar cell interconnect comprises a loop section, a first flat section at a first end of the loop section and coupled to a first battery terminal, and a second flat section at a second end of the loop section and coupled to a second battery terminal, and wherein the respective wire bonded connection is welded to the first flat section.
16. The battery module of claim 15 , wherein the respective wire bonded connection is fabricated from the first metallic material, and wherein the first flat section is fabricated from the first metallic material.
17. A method to assemble a battery module, comprising:
inserting a first battery cell comprising a first terminal into a battery housing;
inserting a second battery cell into the battery housing adjacent to the first battery cell, the second battery cell comprising a second terminal;
electrically coupling the first and the second terminal using a bus bar cell interconnect;
welding a first end of a wire in a wire spool to a voltage sensing terminal of a printed circuit board;
welding a second end of the wire in the wire spool to a welding region of the bus bar cell interconnect to form a wire bonded connection; and
cutting the wire to release the wire bonded connection from the wire spool.
18. The method of claim 17 , wherein the welding of the first end and the welding of the second end are performed by laser welding.
19. The method of claim 17 , wherein the welding of the first end and the welding of the second end are performed directly from above the printed circuit board.
20. The method of claim 17 , wherein the voltage sensing terminal comprises a voltage sense connection tab attached to the printed circuit board.
21. The method of claim 17 , wherein the wire and the wire spool are fabricated from a first metallic material, a body of the bus bar cell interconnect comprises a second metallic material and the welding region of the bus bar cell interconnect comprises a metal piece fabricated from the first metallic material and attached to the bus bar cell interconnect.
22. The method of claim 21 , wherein the first metallic material is aluminum and the second metallic material is copper.