Sounds like a bad battery. Batteries usually have a 1 yr warranty, you may be able to get a new one from Acer. If the laptop runs fine on wall power, the issue is not the charger.
thanks but the battery is about 13 months old now and i dont hold much hope of getting a new one from acer. Poor show when you have to buy a new battery every 10 months or so as they are kinda expensive