Electrical voltage in Europe is 220. The USA uses 110 volts.This is the legal standard throughout most of Europe. I would suggest you to check with the people whereever you're staying. I would say you need to have somekind of voltage converter.
the times that I have traveled out of country I have just used the adaptor and it has never caused any issues with my battery, charging functionality, ect. Most of the airports sell charges as well that will fit the outlets over seas, but again the adaptor will work just fine.
Check your charger it it can handle 220/110 V. The info is on the charger sticker. What you may need is and adapter for the plug. You can get it at RadioShack