I, like others have standardized on AA batteries. The only survival related exception to this is my headlamp which takes 3x AAA batteries.

With the headlamp batteries fully charged, there is well over 100 minutes of burn time when the light is on low and about 50 hours on high.

With this amount of burn time, I don't mind having AAA batteries and never carry spares for the headlamp as I could not foresee having to have the lamp even on high for 40 + hours which would stretch for many, many nights with judicious use.
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Earth and sky, woods and fields, lakes and rivers, the mountain and the sea, are excellent schoolmasters, and teach some of us more than we can ever learn from books.

John Lubbock