Aspire 1642 Battery wont charge and is slowly discharging but runs on AC power

Hi, I know you must have read people all the time complaining about batteries not charging. I think my case is different. My power adaptor had a broken wire next to the dc plug where you connect to the computer. Before I repaired it, it was always alternating between mains and battery power because the wire was connecting and disconnecting itself, though I tried to avoid this intermittent situation it still happened. So I cut the cable and resoldered the wire and now the adaptor is working ok. The thing is, now the battery won't charge, in the plug/battery icon yesterday it said 33% charging, I left it all night plugged in and the charging light was orange as normally is when charging, today I turned on my computer and now it is 25% but it still says charging and the orange light is still on. So the wierd thing is, the battery port detects the battery as normal and shows its capacity, but though the computer is plugged to the wall 24/7 it is slowly loosing its charge.

Could the battery be busted or did the "alternating from AC to DC fried my charging section of the main board? I think this model doesn't have seperate charging boards so if this is the case I'm so screwed, please help. I don't wan't to spend money on a new battery with out being sure if its the battery's fault, also, is the anyway I can know it's the battery or the main board?

Thank you