I think your notebook is a little bit older… right?
Well, I think the battery is faulty… this is nothing unusual and can happens after a long time of usage.
My old battery cannot charge as well… but in my case it does not matter because I use always the AC adaptor.
So in your case I recommend replacing the battery with a new one.
Please check the label at the back of the battery… there is a part number which helps you to identify the right battery for this notebook.
If found this very nice article about problems with battery charging:
If it doesn’t help it’s time to replace the battery. You can get such a battery from an authorized service provider or on some online places. If you search with the current battery part number on Google you should find enough shops where you can buy such battery.