Design of lithium, primary battery comprising several parallel strings for high pulse current loads

The problems which result from parallel connection of high rate lithium cells are discussed. It is shown how thermal management is exacerbated by unequal current sharing, particularly toward the end of discharge, and that some force of thermal/current overload protection must be included. Experiments are described which allowed selection of protective devices which allow good utilization of the battery high current capability but at the same time prevent thermal runaway from occurring. The importance of additional cooling is also shown. The tradeoffs which are possible between the duration of high current pulses and the maximum ambient operating temperature are explained. Test results are given which illustrate the performance of the battery at high ambient temperatures