Iphone dying faster than charging?

So my iphone 5 has been dying faster than it can charge like I'll put it on the charger and listen to music or skype and usually my phone will get to 100 and stay there while it's on the charger but lately it's been dying really fast even when on the charger and charging really slow what do I do? I have done all the things help slow how fast the battery does for iphone but no help… I did buy a new charger when mine broke around the same time this happened but it's an iphone charger not some fake brand and I've been keeping it outside for music (on the charger as well) when I swim but I kept it under a towel… Did I mess up my battery or something? Did it get to hot?

I have the same phone, i guess you have to take proper care of it. Try turning off the bluetooth sign and make the brightness lower ( lower than half) and umm when you charge and its 100% take it out, basically don't charge too much. And also when your opening apps. Don't forget to double press the home button and swipe upwards to close the apps. That'll save u some charge
i hope this was of any help.
take good care of your phone.

Buy another new certified charger that will deteriorate near the plug.

The iPhone will know when to stop charging when it gets to 100%. Heat will deteriorate the battery OVER TIME. In fact, the first time you use the phone or charge the battery will it start to get weaker.There's no harm in keeping it in the charger. But consider going to Best Buy or any other iPhone repair store.

As to this question, I think Battery Doctor can help you to optimize your battery. This is a free app and it is very easy to use. Many features are included. Here it is: http://freewaretube.com/battery-doctor-the-best-free-app-to-help-you-prolong-ios-battery-life/