Is it good to let batteries run out before charging?

            Most modern batteries, including all those used in Mobile Phones, whether its is an Android or iPhone, make use of lithium-ion batteries. Compare these to traditional batteries and you will find out that these batteries can charge faster and last longer. Apple and other top cellphone brands measure their batteries' lifespan in cycles, with one cycle equal to a 100 percent discharge. This doesn't mean that you have to completely drain out your battery before charging. It is best to split charge cycles across multiple charges to strengthen the batteries. 

            Most  manufacturers suggest that you never let your phone battery get below 10 percent and not letting it charge 100 percent for a long time. They are both bad for your phone batteries and it can cause damage. Leaving your device plugged in until it has stored every last drop of energy can reduce its lifespan in a long term. You should take advantage of your device's built in charging design, which will likely be a "quick charge' from 80 percent and trickle-charge from 80 to 100 percent. This design ensures that you can charge quickly but stops your device from overcharging. 

            So keep your bar in the middle and charge from 15 to 80 percent to keep your battery lifespan longer.