Display sometimes not working; Sign of dying 12v Battery?

Sometimes when I crank (well, "start") her up the right side of the Multi-Information Display (the consumption & odometer side) doesn't show up. I'm guessing from foruming around that the 12v battery is giving up the ghost. I don't know if it's the original battery, I'm the 2nd or 3rd owner -- I guess I could look. It seems to act up first thing in the morning, and the rest of the day the display is fully visible.

She also sometimes doesn't "start" the first time I press the brake and mash the start button. (Please no sexual jokes, stop it! Stop it!)

What are the other symptoms of a dying 12V battery? She might be displaying impotence in other ways, to which I'm currently unapprised.

 

That would indeed be bad

 

Thanks, I'm hoping that's it. Yes it's only the right half the display (Odometer side) that's gone out completely, but only every few days, seemingly after it sits for more than 12-14 hours.

 

[SOLVED}: Yesterday was the day! Car wouldn't start, display fading & flickering, excited triangle. Got AAA out for a jump & battery test. 87 CCA, should be 325 wow! The amazing part: that was the OEM factory battery, lasted 10 years! AAA wanted $350 for a new one -- I've bought batteries from them before, so I'm not against AAA, but I knew I could go down to Pep Boys and get a Bosch 12v with a 48 month warranty for $152. Did so and put it in myself yesterday, easy job. So far so good, seems strong. I will update this if I have problems.