Thermal management systems for battery packs

Abstract

A cordless power tool has a housing which includes a mechanism to couple with a removable battery pack. The battery pack includes one or more battery cells as well as a system to dissipate heat from the battery pack.

1 . A battery pack comprising: 
 a housing;    at least one battery cell within said housing;    an electronic circuit connected to said at least one battery cell and including an electronic control unit;    a temperature sensor for sensing a temperature within said housing and in communication with said electronic circuit;    wherein said electronic control unit disables said electronic circuit when a sensed temperature exceeds a predetermined temperature.    
   
   
       2 . The battery pack according to  claim 1 , further comprising a power supply within the said housing for providing electric power to said electronic circuit.  
   
   
       3 . The battery pack according to  claim 1 , further comprising a driver circuit within said housing in communication with a pair of semi-conductor devices of said electronic circuit.  
   
   
       4 . A battery pack, comprising: 
 a housing;    a plurality of battery cells disposed in said housing; and    phase-change material disposed in said housing in heat transfer relationship with said plurality of battery cells.    
   
   
       5 . The battery pack according to  claim 4 , wherein said phase-change material individually surrounds each of said plurality of battery cells.  
   
   
       6 . The battery pack according to  claim 4 , wherein said phase-change material is disposed in a gel-filled covering tube wrapped around said plurality of battery cells.  
   
   
       7 . The battery pack according to  claim 6 , wherein said plurality of battery cells are individually wrapped by a plurality of gel-filled coverings.  
   
   
       8 . The battery pack according to  claim 4 , wherein said phase-change material is disposed in a carrier that is disposed in heat transfer relationship with said plurality of battery cells.  
   
   
       9 . The battery pack according to  claim 8 , wherein said carrier is formed from plastic.  
   
   
       10 . The battery pack according to  claim 8 , wherein said carrier is formed from a material selected from the group of aluminum, copper, and carbon fiber.  
   
   
       11 . The battery pack according to  claim 8 , wherein said phase-change material is disposed between heat fins disposed on said carrier.  
   
   
       12 . The battery pack according to  claim 4 , wherein said housing is made from metal.  
   
   
       13 . A cordless power tool, comprising: 
 a plastic tool housing;    a motor attached to said tool housing;    a battery pack including a metal pack housing connectable to said plastic tool housing and at least one battery cell disposed in said pack housing.    
   
   
       14 . The cordless power tool according to  claim 13 , further comprising a drive mechanism attached to said motor.  
   
   
       15 . The cordless power tool according to  claim 13 , wherein said tool housing includes a handle portion.  
   
   
       16 . The cordless power tool according to  claim 13 , wherein said motor is disposed within said tool housing.  
   
   
       17 . A battery pack, comprising: 
 a housing;    at least one battery cell disposed in said housing;    a circuit disposed in said housing;    a temperature sensor in said housing and in communication with said circuit; and    a temperature gauge mounted to said housing and in communication with said circuit, said temperature gauge providing an indication of a temperature level detected by said temperature sensor.    
   
   
       18 . The battery pack according to  claim 17 , wherein said circuit directly connects said temperature sensor to said temperature gauge.