The battery is about two years old.....
How old is the battery? It may just be dead from age. Li-ion batteries have a "memory" so you don't need to condition them like other rechargeables.
whoa, very misleading response you got above. lithium batteries do NOT have a "memory", hence no need to condition between charges, fully discharge, etc.
secondly, lithium batteries decay from the moment of production until death. doesn't matter when it takes its first charge.
hope this helps? i'm sure you've come to understand that battery won't hold a charge, now it's just about helping you understand why!