Xplainsit

This is a very common question and is often misunderstood. The easy answer is no you do not need to let it run dead before charging it, assuming you have a relatively new phone from the past 10years. The issue was the older battery technologies.  Nickel- based batteries did have a memory and it was beneficial to run them all the way down before charging. Pretty much any phone produced in the past 10 years has a lithium-ion battery. Lithium-ion batteries don't have a memory and it is actually back to let them run all the way dead. It is best to keep it above %50 charged anytime it is possible.