I recently learned that I should stop using task killer apps to save battery life. I have Watchdog installed on my phone that monitors the CPU that each app consumes. Is the amount of battery life an app consumes purely a factor of how much CPU it's using? In other words, the amount of RAM used by the program doesn't dictate how much battery drain it's using? Secondly, if I minimize a game like Angry Birds or World of Goo simply by pressing the home button, such taht when I opent he game agian, it loads right away and I am back at where I left of, is it take up more battery in the background thatn if I had killed the app?