Much like old humans, old iPhones have a tough time holding their juice -- and part of
the reason why is how you charge them. "Charging my phone is a breeze," you say. "What could possibly go wrong?" you say. As it turns out, some of our seemingly harmless habits are doing slow, silent, deadly damage to those precious lithium-ion batteries.If your palms start sweating when your battery drops below 90%, you need to chill. Maintaining a full charge is not the most efficient way to keep your phone battery strong. In fact, experts suggest letting your phone coast through the day between 30 and 80 percent full. That's where it's most comfortable, and will run most efficiently. So stop juicing it overnight, and instead go for shorter and more frequent bursts throughout the day https://www.thrillist.com/tech/nation/how-to-make-your-iphone-battery-last-longer-iphone-charging-tips/tech
