12v Battery Age?

Looks pretty new. Can't be a 2014 - they don't last that long.

The definitive test is an old school load test, usually free at an auto supply.

 

I’d load test it (with one of the electronic load testers), go from there.

last battery I put in our 2010 was September 2015, still testing like new. I’m using a Solar BA5 (latest iteration Solar BA9).

note, the pictured battery is an Optima Yellow-Top, with 450 CCA spec, and maybe 38 Amp Hours. Not really optimal for Prius; when I replace it I’ll go with something with specs closer to original, say 325 CCA, and higher Amp Hours.

 

While I've never used the old school tester, I have a digital tester and based on my experience, wouldn't trust that too much. It's easy and cheap, but I'm not sure how accurate. Which type do the auto supply places use? I suppose it varies.

 

If that car was always dealer serviced; you should be able to pull up the history through it's VIN.

 

If the "old school" load tester (still available everywhere) has analog meters and ventilation it is more likely to be accurate. The better units are called "carbon pile" load testers.

 

I think harbor freight still has the lower pictured one for around $20; pretariff price. That intel is more than a year old....

 

The David Letterman Battery Tester