It takes a while to get used to a new cell phone. The real details are in the manual you would have to download or you can just wing it.
A Wall Street Journal online article states that most of us are complaining about how fast our batteries lose their charge during the day.
There are some things you can do, such as lower the brightness of the screen, have the screen close after a certain time frame or more importantly and only if you don't always need it, you can disable 4G.
For your emails and calls, 4G is not that necessary especially if you don't have a way to charge your phone during the day. If you are streaming movies or using lots of data, then you will want to keep your phone set on 4G.
Besides, not every area has 4G capabilities and your phone will constantly search for it if it is set to 4G. Searching uses up your battery!
Check out Green Power Batter Saver in the Android Marketplace.
Read the article from the Wall Street Journal:
So until 4G is everywhere, here is what you can do on your Samsung Charge courtesy of a blog I came across: www.xda-developers.com:
-go to settings - wireless and networks - mobile networks - system selection - CDMA mode.