Bad Battery on EMachine M622-UK8X?

Question

I have an EMachine M622-UK8X that’s a few years old. Now when I plug it in to an AC outlet the battery light flashes a few times, then goes out. If I try turning it on with no AC connection, no lights at all. I don’t want to spend the money on a battery if it’s a bad AC adapter or something else. Is there any way to verify my battery needs replacing?