When you say "dying fast" can you be a little more specific...define "too fast" if you can

Here's a couple of things you can check and do:
--Charge your phone every day by powering off the phone completely and using the provided charger and usb cable. You can go a day without charge, but generally speaking it's good to turn it off and charge it daily...or more often if necessary.
--You mention OS, 44% is not necessarily high...it depends on what you have running (widgets and other apps). Keep in mind that widgets are nice, but some can use a lot of battery and therefore OS time. Check to see what you having running. Do a menu>settings>apps>running apps. That will give you an idea of what is running and consuming OS time. You may find apps running that you have no use for and don't realize they are running.
--If you have a 3rd party "Task Killer" installed that would be the first thing I would uninstall. 3rd Party Task killers seldom do more good that harm.
--If you have apps that require a periodic sync like weather, Facebook, news feeds, email etc then consider changing the frequency that they sync or stop them from automatically syncing and do it manually.
--Things like GPS and Bluetooth use OS time. If you're not actively using them turn them off.