One of the most irritating factors when it comes to phones is the possibility that your battery is going to be drained ridiculously quick. It seems like even if you charge it to full, it can’t even last you the rest of the day, and that can put you in a very uncomfortable situation. The good news is that most phones, (although people did not know this), have cases that can be bought which allow them an entire extra battery.
These cases are not made for every phone, (in fact, extremely old models will not be able to find cases like this). It simply attaches on like a normal case, and plugs in to the bottom of the IPhone, (or wherever you normally enter the charging cable). It can be charged using the charging cable, and helps you lengthen your batteries life, due to it not overcharging as much. These cases are generally inexpensive, unless you buy a case that is higher quality, (which is suggested).
$39 @ IPhone Battery Case