Many cameras come with an AC battery charger. But charging from a USB power source can be far more convenient when you’re traveling. The good news is that there are USB chargers out there for the batteries used in common camera models, even if you have to hunt a little to find them.
I take photos and travel. I do it for a living. Seven continents. Dozens of countries. Up mountains. Under water. And a bunch of places in between. Based in Washington DC.