When to replace the 12 V battery?

and yet, we see little evidence here for optima longevity

 

Of course it could, because it is not a deep-cycle battery, but a regular Group 51 starting battery, slightly modified to fit the Prius terminals and vent tube.

Incidentally, people take fake CCA testers way too seriously, in my opinion.

 

Optima is higher CCA and lower amp hours, which is not really what you want with a Prius? That's the uneducated sense I'm getting, anyway.

That said, I put in an Optima Yellow Top 4 years ago, and it's still in the pink. BUT, it's garage stored, and any day the car sits idle I hook up a CTEK 4.3: it lives a sheltered life...

 

Of course it could, because it is not a deep-cycle battery, but a regular Group 51 starting battery, slightly modified to fit the Prius terminals and vent tube.

Sorry, thought this was already understood. Maybe it just wasn't very clear.

Incidentally, people take fake CCA testers way too seriously, in my opinion.

Can you fill me in on fake CCA testers?

Pep Boys clerk hooked it up to a tester about the size of a roll around battery charger and it showed the numbers I posted. Around 12.4 volts and 612 cca. I got it home and connected my OTC 3183 (made in the good ol USA) and it tested at 625. Is that not fairly accurate? Accurate enough and repeatable enough to track trends and know ahead of time when a battery replacement may be in the near future? Is there something else I should be looking at?

 

Weird, but my 2013 Prius C with 142,000 miles on it is still on the original 12v battery. Car starts no problem, I've checked the voltage, all nominal... I guess it really makes a difference not being under the hood...

 

Some auto parts places will purposely set the CCA higher than the battery specs so it would appear that the battery is very low and needs replacement. For example of the battery spec is 450CC, auto parts will put it on 600CCa & run the test but won't let you see them select "600ccA on their tester. They'll just show you the shiny red light and go "Oh our test shows that your battery is weak, come in and we'll get you a new one." How convenient.

 

Battery replacement isn't about mileage, it's about years. If you live in a Southern state, I would replace it every 4 years.

 

North state people are always left out on battery life topics.

 

As long as you have a little jump pack in the glovebox, you can use the answer "when it no longer works reliably", and spend the rest of your brainpower on more interesting questions.