Most chargers these days work off of 100 - 240 volts. So at worst case, you will need an adapter. And those are readily available.
I use the iGo products (
www.igo.com) I use a Charge Anywhere as my main unit, which is both a wall charger and has an internal battery to charge devices when you are away from a wall outlet. The cable also allows charging from any USB outlet, both on a computer or one of the little devices that convert wall voltage to USB.