Inspiron 1545 battery

I'm not sure what's going on with my computer, but it's gotten to where it dies when it says its 50% charged.. It just started recently. Before it would get down to 10% before it died then it just somehow started making it's way up. The battery is only about 3 months old. I had to get new one when the battery that came with the computer experienced "technical difficulties." I really appreciate any help y'all could give me! Hopefully I won't have to spend another $75 on a new battery.