Re: loss of battery power
Welcome to Android Central! Which phone do you have? Checking battery stats after only a short period of usage gives you a skewed picture, so wait until the battery is down to 20-30%, then show us screenshots of the following:
1. The main Battery screen.
2. The fullscreen battery graph screen (to see total Awake time and cell signal strength).
3. The Screen category (to see your total Screen-On time).
4. The Cell Standby category (if present, to see your Time without Signal).
If you have a removable battery, it could be starting to fail. You could try a new battery. Or a quick and dirty test is to remove the battery, place it flat on a table, and try to spin it--if it spins freely, it's bulging in the middle, which is a bad sign. But even if it doesn't spin, it may still be worth trying a new one.