My nikon cool pix s 3100 is plugged in but won't charge

I have a Nikon S 3100 and it is about 2 1/2 years old. When I plug it in to the wall (the outlet works) the little crooked arrow blinks green but it won't turn on. It's been charging for about 2 hours and it still won't turn on. Any thoughts?

Have you ever let your Li-ion battery sit while it was fully discharged for any length of time (three days or longer)?

It is very important to keep stored batteries fully charged.

I just recharged one of my Li-ion batteries and it took nearly 4 hours to fully charge.

Just put your battery in your charger and let it charge over night.

Coolpix S3100's battery needs just 2 hours to charge. I think your battery is exhausted and you should try a new battery.

At 2 1/2 yrs old the battery is probably finished. Rechargeable batteries don't last for ever.
You need a new battery.