I have been following this thread as I had a problem with My TPMS also that was a bad sensor . After it was replaced the only one who could reset monitol was a Chrysler dealer and they had to upgrade their software to do it .
I have been going to disect the old sensor that was bad to see if I could replace the battery like was stated in this thread . Well the sensor Part # 52088990AC was molded as someone stated . I had to cut and pry the thing apart to find the battery . Now manybe if I worked on 5 or 10 I could find a way to get it apart . But I would say its not rebuildable . Their is no easy access to the battery . This thing is tuffer than working on an Apple iPhone !!!
I would post some pictures but don't know how to attach them to this thread .

Thanks and hope that helps the next Guy !!