Using third generation ipad with new 7.0.3 operating system. New feature shows open apps when your double click button. Can u still close apps this way? New upgrade is eating my battery life

Yes, you can still remove apps from the recents list. However, that probably won't do much to improve your battery life as very few apps are actually doing anything in the background. Notable exceptions would be apps that are streaming music or activel using GPS (e.g. navigation apps). Just swipe up on the app window.

If you want to increase battery life, turn off autobrightness and turn the brightness down to the lowest comfortable setting. Turn off Background App refresh (Settings>General>Background App Refresh>Off). If adjustments in settings don't help, sync your iPad then restore as new using iTunes.

To quit open apps from the recents list Double click the Home button to show the screen with running and recently used apps. Each app icon will have a sample page above it. Flick up on the page (not the app icon) and the page will fly away and the app icon will disappear. This quits that app.

There are quite a few posts and answers about ways to reduce battery use. iOS 7 installed many new features and turned them all on. Probably turned screen brightness all the way up too.

Turn down screen brightness. Then look through your settings for items that you don't need on.