OP,
I had a similar problem. My Dell laptop battery died out. I ran on AC power for about a year. Then finally, I ordered a cheapie on Amazon. It wouldn't charge. I ordered another cheapie on Amazon. Still wouldn't charge. I knew the AC adapter was good, the computer would run on the AC adapter, and I had 2 of 'em that worked fine. Contacted the manufacturer of the second cheapie. He had me change some settings in the operating system that ran the battery completely dead. Discharged way beyond what it was supposed to be. The goal was to "shock" the new battery into charging. That didn't work. A friend went into my computer and found that the charging circuit on the motherboard was fried. This is a common issue. If you run with a bad battery in a laptop on AC power, you run the risk of damaging the charging circuit on the motherboard.
If the pieces fit together, this could be your issue. My solution? New motherboard? Heeeeck no! Way too expensive and too much trouble. I ordered an external battery charger for my specific laptop battery. Where? Amazon of course! Now since I have 2 batteries and an external charger, one is charging while one is running my laptop. I also have another laptop now too. Why? The external battery charger was my second idea. A new laptop was my first. Either way you look at it, problem solved.
Good luck!