Thuds/clunks when NOT charging?

[mod3lWii]

I made an appointment in the app but until then, thought I'd get feedback here, too. In the last week, I've been hearing thuds/clanking from my car while it's in the garage unplugged. It sounds like the noises you hear when supercharging - where the battery expands, etc due to temperature changes and the like. Have I just never noticed this all these years and it's normal? Or is something possibly amiss? Basically I'm sitting on the couch and every hour or so I'm hearing a bang in the garage and I think it's the car. Not sure if maybe it's also waking up when it shouldn't and the noise(s) are the battery contractor noise or something...