I was always under the impression the apps were not "doing anything" but just sitting there and not consuming any battery power. Those apps were in a "static" state until called upon again. But I guess that's not the case.
A great many are exactly that way - hence my statement about run mode.
When an app's mode = sleep, it consumes 0% power and it's presence in memory doesn't matter - unlike the processor, power draw for ram is constant, whether filled or not.
I'd like to say that applies to most apps for most users.
Some apps won't sleep - best examples off the top of my head, various monitors and system loggers, or, your music player - that'll keep going while you run something else or even turn the screen off.
Some turn on, do their thing, see if they're in use, go back to sleep if not, and later wake up and repeat the same cycle. Many apps do that - email, weather and the like.
So it's true that background apps normally sleep but that varies by type.
Then comes resources used.
Some apps want your location, and some will go for it with GPS. And if one wants location details, it'll start Google Maps in the background. Now you've got two apps running and tapping wifi and GPS if they can - when all you wanted was geotagging on your pictures or some nice weather widget playing.
But other apps will simply do their thing, and maybe write some data to storage for you, and that's all, such as a good email app.
So, always look at app permissions before installing a new app - you can predict a lot about what to expect the more you know about those. We have a sticky thread in our Applications forum explaining those by a real expert.
And maybe keep a good monitor handy, lately I've been recommending Gsam Battery Monitor, because sometimes a bad app, or bad installation of one, or bad configuration can sneak up and cause trouble.
I think you've seen my battery graphs here - I'm highly conscientious about my apps. I don't tinker with my radios or killing apps. When I turn my screen off, my phone sleeps. The battery usage is practically a horizontal line. And so if I want to get a faster charge, rather than kill apps, I turn off the screen.
That comes with tradeoffs though.
Some apps that I like, I won't use. I still miss my favorite live wallpaper, but I chose battery life.
I like keeping a live news feed so I can see what I need at a glance. But I gave that up in favor of battery life and having to surf and refresh.
I like trying new apps, but I don't keep the ones I try and like until I'm convinced that they don't cause sleep issues.
I think of it as battery vs fun.
The more fun features you're using, the more power, ask any 3D gamer for example.
Some people have no fun and use their phone bare bones because they want days-long battery life.
So the best I can offer are some rules of thumb rather than rules because we're all individuals with individual preferences on how we do things and what we want.
Sorry this got so long, hope it helps!
)
). Still I left it alone from 1637h til 1730h and lost just 1%
