Iphone Battery And Performance Apple Support Five Tips To Maintain Your Iphones Battery Healthy 5 tips to maintain your iphone's battery healthy. 1. keep your iphone at room temperature. that means between 20 and 25 degrees c. the worst thing that can happen to a lithium-ion battery is to have a full charge and be subjected to elevated temperatures. so don't leave or charge your iphone in your car if it's hot out. 5 tips to maintain your iphone's battery healthy. 1. keep your iphone at room temperature. that means between 20 and 25 degrees c. the worst thing that can happen to a lithium-ion battery is to have a full charge and be subjected to elevated temperatures. so don't leave or charge your iphone in your car if it's hot out. Anyone knows how to improve battery life on iphone 7/7 plus, thanks! " many people have upgraded their iphone to an iphone 7/7 plus because of the poor batter battery life. however, things look sound a little frustrating. the...