Is it my iPod charger that's messing up or it is my actual iPod?

So I've had my iPod touch 4 generation ever since January 1, 2011 and I use it practically all the time, so I have to charge it alot. In that time I've already gone through a charger, now I'm using one that I've had for probably about 3 months or so and for the past two days, the charger or battery or the iPod as a whole has been messing up and it's really starting to freak me out because I'm so attached to my iPod. At first I thought it was the charger, then I thought "Well I use it alot so maybe the battery is going dead" Which for me is the worst case possible. But I'm wondering if it's charging, but it's just not indicating it. Please please Please help me!

(for the record I use the "Nikon EH-68P AC Adapter wall charger, which seems to work but I'm not sure if it's safe)

I can't answer your question, but if it is your battery, then you can take it to apple for a new one (as long as you didn't jailbreak it) since its a part of your one year warranty