Chris Malcolm wrote:

If a Li-on battery camera has a battery recharging socket then it's
easy enough to make up an AA battery of the appropriate voltage with
the right plug on the end. Then you can have the best of both worlds.

Very few Li-Ion powered cameras (or AA powered cameras for that matter)
have internal chargers any more. My Canon G2 has that feature, but
current G series models don't have it.

You could still charge the Li-Ion battery with ten AA cells and a 12V
charger. All this assumes that you're in a place with no AC or DC power.
But the advantage of the AA cells is that you just buy some Alkaline or
Lithium disposable batteries at the convenience store, and you don't
need to worry about chargers, cables, etc.

For a D-SLR, most of the vertical grips can take six AA cells or two
Li-Ion packs.