My advice is that you don't need to replace the batt yet since it is below 3 yrs. but charge it back up when it is bellow 40-50%. You don't always hv to wait until it is 30% or less. I charge anytime when I'm not using my iphone, even at 70-80% I put it on charge. Also Less waiting time. And don't worry ur batt will not wear out faster.