This could be very helpful.

There's nothing more frustrating than seeing your battery die when you're expecting a call or if you're relying on it to provide some entertainment for your commute home, but the Battery University have provided a few tips to get some more juice from your phone. Here they are. 1) Charge your phone in short periods If you're one of the people that are happy to let your phone run down to 1% battery life before charging it up to 100%, it's likely that you're doing some damage. The constant stress that this puts on your battery can eradicate its longevity, meaning you have re-charge it sooner. Essentially, those long periods when you charge your phone overnight could be doing some damage. 2) Unplug when it's fully charged. On a similar note, they also fully recommend unplugging your charger as soon as the battery reaches 100%. Failure to do so could wear the battery down in the long run. 3) Remove the case when charging Phone cases insulate heat which can reduce how effective your battery is. By keeping your battery cool, it's likely that you'll prolong its life. Here's hoping that these tips can keep your phone alive for a bit longer.