This myth seems as if it could be legitimate due to the idea that any additional processes use system resources, and the more programs you have running, the slower the device will be. However, both operating systems limit just how much these apps can do while they’re running in the background; Android, less so than Apple. But the amount of drainto your battery is quite minimal, and as far as slowing down your phone is concerned, it’s unlikely that multi-tasking is the culprit.
Task killing apps are essentially useless, and while they do their job by closing background apps, they aren’t actually saving much in the way of resources, or battery life. You see, both Android and iOS will automatically kill a task when more memory is needed and neither will show a noticeable difference without any apps running in the background.
Lithium-ion batteries actually perform better when they remained charged. Older NiCAD and NiMH lasted longer when you let them fully drain before charging back to 100 percent. Modern batteries don’t face this same sort of problem because they don’t have “cell memory” like the older NiCAD and NiMH rechargeables.
This is another myth that was true at one point, but as battery and charging technologies have improved, it’s now completely false. Older batteries weren’t smart enough to realize when they’re full, and overcharging them consistently led to decreased battery life over time.
Today’s charging mechanisms are smarter. Once your phone is fully charged, it stops drawing electricity.