My Sony DSC-H5 eats NiMH cells like candy, which means I must haul along a pocketful of the things. That means I often wind up with a case containing one charged pair and one uncharged pair.
Ditto for swapping cells in the blinky lights on our bikes.
Pop quiz: which pair is which?

It’s pretty easy:
- Nose-to-tail = as in the camera = charge ’em
- Nose-to-nose = as in the charger = ready to use
You could do some remote psychoanalysis based on that sort of behavior, but you’d be completely right.