While we can’t speak for other platforms, it seems that this does not apply to iOS devices, at least according to former Apple Genius Bar technician, Scotty Loveless, who recently wrote a blog post on how to prevent iOS battery drain.
We’re sure that there are some of you who open up the multitasking window and swipe apps up to close them thinking that this could improve your phone’s performance and save battery life. Well you’d be mistaken because according to Loveless, this will actually make your battery life even worse.
This is because all you’re doing is removing the apps from the iPhone’s RAM, which means that in event that you want to reopen the apps, your iPhone will have to reallocate the space in the memory, which in turn will consume more resources, which could then lead to a battery drain. Loveless also states that iOS will detect when your device needs more memory and will automatically close apps in that situation, meaning that there’s really no need for you to get involved.
It has also been mentioned that apps only run in the background when Background App Refresh is enabled, so if you’re looking to conserve battery, disabling that could prove to be a better idea than quitting apps.