If your laptop battery stops charging properly, could very well be that your battery is on the way out, but there are a couple of other options I’d like you to check out first based on my own personal experiences. First, make sure that both the port and the connector going into it are free of debris. Wipe off the connector and try blowing a few times into the port. (If you have some canned air, that’s even better.) You’d be surprised how many times dirt or debris are blocking the connection.
Next, check your charging cord for any visible signs of damage, especially around the neck. They can be quite vulnerable there. I usually like to buy a backup charging cord in case my original goes bad. (I find that the cords invariably do.) If you have another cord, or a friend has the same cord, swap it out and see if that helps. It’s even possible that a friendly tech at a local computer store might let you test out a cord to see if that’s the root of your problem.
Check your wall plug or power strip plug. If you’ve tried charging using the same plug, that plug could be the one with the problem. If you’re using a power strip, make sure it’s plugged in at the wall and also try another plug on the strip. (And make sure the power strip is turned on, I’ve pulled that trick in the past.)
When taking the battery in and out, make sure there’s no dust or debris blocking the connection. Again, just blow on it or use some canned air.
I can’t promise that any of this will help, but you never can tell.