My iPhone 4s only charges until 4%, and then dies! Why?

I have an iPhone 4s in good condition, and I recently plugged it into a charger, which was in bad condition, and the charger wasn't working, so I went out a bought another charger which did not work either. So soon after I used someone else s iPhone charger, and came to find out my phone only charged until it turned on at 4% then dies after that! How do I fix this, please help!

How to turn your iphone on from the computer?

My sisters iPhone 4s has been stolen at school and whoever has it has turned it off, we tried tracking it on Find my iPhone but it says it is offline and will notify me when it is turned on. I know there's a way to turn you iPhone on from the computer but I can't figure out how!

Can at&t detect that i'm using a iphone when it is unlocked?

I have an iphone 3gs and i was using it without a data plan when i suddenly got a text saying that i'm using an iphone and that i need a data plan.i've been reading around and if i unlock the phone i can apparently use the iphone without a data plan.true or not?

How to unlink my iPhone from an Apple ID?

I just purchased the iPhone 5. I chose to reboot from an apple ID-- but apparently my genius ex linked a bunch of different apple id's to the old phone, so now the new phone is linked to those as well. Every time I click on settings I'm asked to enter a bunch of passwords for accounts I didn't even know existed.

So my question is: Is there anyway to disassociate my phone with those old accounts?