I can't charge or sync my iphone 5?

I need some urgent help here, you see I have this Iphone 5 (I haven't updated to IOS 7 yet, so I'm stuck with 6) And when I charge it the thunder bolt sign does not appear on the battery image on the top. It also doesn't really charge at all, when I leave it for a full hour it only charges to 3% or stays at 0%. I tried changing my charger, cable but they're all fine. Also most of the time I play while its charging so I think it might be the batteries problem but i'm not sure.
I'm kind of certain that's why it won't sync either, it has only happened since yesterday and it's starting to get on my nerves because its always at 1% and dies any minute. If you have any idea of what's going then please tell me! :/ I'm sending my Iphone to get it fixed but I really want to fix it myself since it would be better.

Your best bet is to send it in. The lightning port maybe defective. What you could try is get one of the air compressed cans and blow the air in the port. There might be dust in side