Thinking of extra battery for vaca

I have gotten hooked on the Kindle app and am thinking about getting an e-reader but haven't yet. (and besides a BB compared to a Kindle or iPad to the head when I start falling asleep reading at night is much better :o) I have rediscovered my joy of reading so much! I am looking forward to reading on the beach this summer! I'm apprehensive about battery life! I have seen those turbo chargers and thought about that and then I read here many who carry extra batteries, so maybe that's a good move. Stupid question, how are they charged? I have a charger for my digi cam battery.....would it work or do I need to buy another charger too?