Battery issues

I have an Inspiron 5537 and the original battery recently completely died on me. The AC adapter will power on the computer, though. I bought a new battery for the laptop, and the battery light will light up saying that it is detected, but the battery icon will say something like, "78% charged" and "01 minutes until fully charged" without even charging. Furthermore, as soon as I unplug the adapter, the laptop shuts off as though the battery isn't working. Does anyone know what could be the problem and how to fix this? I'm desperate!