Car is kept in the garage on a tender. Just got in and there was clicking coming from the dash. Got out, door would not reopen for a min or so. Got back in and tried to start it, nothing. Can turn key backwards for radio. When I go forward with the key the dash kits up kind of dimly and whe. I try to start it I just get clicking from the engine Bay.

Thinking this is just the battery?

Appreciate the help in advance!