We keep 4 cell , C and/ or D battery Mag-Lite flashlights, upgraded with LED build modules ,in out family cars as utility an emergency , nearly indestructible, flashlights. They are kept in the passenger cabin. But they r still subject to both high heat in summer and freezing cold in winter. So my question is, what in ur opinions , are the best batteries to use to survive the temperature swings, not burst their cases from corrosive battery failure and provide long life power to the LED bulb. Modules?