Battery system with selective thermal management

Abstract

The present invention is directed to battery systems. In various embodiments, the present invention provides a battery system having a first battery group and a second battery group. The first battery group and the second battery group can share a single housing, or be positioned within separate housings. The first battery group and the second battery group can each have a plurality of cells configured in parallel, and the two groups can be electrically integrated. When operating at a low temperature, the first battery group is configured to provide electrical energy to a heating module that selectively heats up one or more segments of the second battery group. In addition, the first battery group also provides energy for initial operation of an electric vehicle or equipment. Once the selected segments of the battery group are heated up to an operating temperature, the selected segments supply electrical power to the vehicle or equipment and charge the first battery group. In addition, the selected segments of the second battery group provide electrical energy for heating other segments of the second battery group. There are other embodiments as well.

1 .- 30 . (canceled) 
     
     
         31 . A method for operating a battery system, the battery system having a first battery group comprising battery cells, wherein the battery cells of the first battery group each comprise a liquid electrolyte, and a second battery group, the second battery comprising a plurality of battery segments of battery cells electrically coupled to one another in parallel, wherein the battery cells of the second battery group each comprise a solid-state electrolyte; the method comprising:
 receiving a signal for starting the battery system;   determining a first temperature of the second battery group;   if the first temperature is below a predetermined threshold:
 using and partially discharging the first battery group; 
 heating a first battery segment of battery cells using energy from the first battery group; 
 charging the first battery group and heating a second battery segment by energy from the first battery segment once the first battery segment is at an operating temperature. 
   
     
     
         32 . The method of  claim 31  wherein the first battery group and the second battery group are electrically coupled in parallel. 
     
     
         33 . The method of  claim 31  further comprising charging the first battery segment by the second battery segment if the second battery segment is at the operating temperature. 
     
     
         34 . The method of claim [ 31  further comprising determining voltages of the first battery segment and the second battery segment. 
     
     
         35 . The method of  claim 31  further comprising:
 receiving a second signal for turning off battery system; 
 recording energy level of the first battery segment and the second battery segment. 
 
     
     
         36 . The method of  claim 31  further comprising discharging the second battery segment if the first battery segment is discharged below a predetermined threshold level. 
     
     
         37 . The method of  claim 31  further comprising charging the first battery segment by a second battery segment.