Method and apparatus for making internal connections within a battery pack

Abstract

A battery pack which provides for the making of internal connections within the battery pack includes a plurality of apertures ( 206 ) having battery pack contacts ( 204 ) in register with the apertures ( 206 ) and are located on top of corresponding metal tabs ( 104 ). The invention allows for a welding tip to be passed through the aperture ( 206 ) in order to weld the battery pack contacts ( 204 ) to their corresponding metal tabs ( 104 ). Once welded the apertures ( 206 ) can be sealed by preferably placing a battery label over the apertures ( 206 ).

1. A method for making internal connections within a battery pack, comprising the steps of:
 providing an access port in the battery pack; 
 providing a battery contact in register with the access port; 
 providing a flat tab having a substantially rectangular cross section internal to the battery pack and in substantial alignment with the battery contact; and 
 welding the battery contact to the tab through the access port. 
 
     
     
       2. A method as defined in  claim 1 , wherein the welding step comprises parallel resistance welding the battery to the contact tab. 
     
     
       3. A method as defined in  claim 2 , further comprising the step of:
 sealing the access port after the battery contact has been welded to the tab. 
 
     
     
       4. A method as defined in  claim 3 , wherein the sealing step comprises attaching a label to the battery pack which covers the access port. 
     
     
       5. A method as defined in  claim 2 , wherein the step of providing a battery pack in register with the access ports comprises the step of:
 molding the battery contact to the battery back such that a portion of the battery contact is presented at the access port. 
 
     
     
       6. A method as defined in  claim 2 , wherein the step of providing a tab comprises providing a tab which is electrically coupled to a battery cell which is located within the battery pack. 
     
     
       7. A battery pack, comprising:
 a battery housing; 
 a battery cell located within the housing; 
 a flat tab having a substantially rectangular cross section electrically coupled by welding to the battery cell; 
 a battery pack cover attached to the battery housing such that the battery cell is enclosed within the battery housing and battery pack cover, 
 where the battery pack cover includes:
 an access port; and 
 a battery pack contact attached to the cover and having a portion of the battery contact presented at the access port such that the battery contact and tab are aligned with each other and with the access port. 
 
 
     
     
       8. A battery pack as defined in  claim 7 , wherein the access port is an aperture which is large enough to allow for attachment of the battery pack contact to the tab through the aperture. 
     
     
       9. A battery pack as defined in  claim 7 , wherein the tab is attached to a flexible circuit which provides electrical interconnection between the tab and the battery cell. 
     
     
       10. A battery pack as defined in  claim 7 , wherein the battery pack cover is ultrasonically welded to the battery housing. 
     
     
       11. A battery pack as defined in  claim 7 , wherein a portion of the battery pack contact is partially molded into the battery cover. 
     
     
       12. A battery pack as defined in  claim 7 , wherein the battery contact has a split end. 
     
     
       13. A battery pack as defined in  claim 7 , wherein the battery contact is welded to the tab. 
     
     
       14. A battery pack as defined in  claim 7 , wherein the tab is attached to the battery cell. 
     
     
       15. A battery pack as defined in  claim 9 , wherein the cover includes an alignment guide and the flexible circuit includes an aperture for receiving the alignment guide. 
     
     
       16. A battery pack as defined in  claim 12 , wherein the split end has a bumped out portion that mates with the tab. 
     
     
       17. The battery pack as defined in  claim 11 , wherein the battery pack contact is cantilevered to either contact.