Thermal runaway detection

A temperature control system comprising:

• a first temperature sensor that measures a first temperature within a first region and generates first temperature signals;
• a second temperature sensor that measures a second temperature within a second region and generates second temperature signals;
• a heat-transfer element positioned in the second region that is configured to heat or cool the first region;
• and
• a controller which is configured to receive the first signals and the second signals and to regulate the heat-transfer element, wherein, during a normal condition the controller uses the first signals from the first temperature sensor to adjust the heat-transfer element to maintain a desired temperature in a feedback loop, and wherein the controller is adapted to determine
• (i) a first abnormal condition when the first temperature indicated by the first temperature signal is decreasing while the second temperature indicated by the second temperature signals is rising, wherein, in the first abnormal condition, rather than attempting to use the first signals from the first temperature sensor to adjust the heat-transfer element to maintain the desired temperature in a feedback loop, instead the controller sets the output of the heat-transfer element to enable recovery when the first abnormal condition ends;
• and
• (ii) a second abnormal condition when the first temperature indicated by the first temperature signal is increasing while the second temperature indicated by the second temperature signals is decreasing, wherein, in the second abnormal condition, rather than attempting to use the first signals from the first temperature sensor to adjust the heat-transfer element to maintain the desired temperature in a feedback loop, instead the controller sets the output of the heat-transfer element to enable recovery when the second abnormal condition ends.