Cold cranking amps

You battery needs to be 12.8 volts or higher with everything off... But the cold cranking amp number is totally irrelevant for a Prius because the hybrid battery handles the cold cranking amps. The 12 volt in a Prius doesn't start the engine, just runs all the computers and sensors, which means a high quality 12volt backup power supply / wheel chair battery with 55 amp hours or higher is not only cheaper than the battery the mechanic will sell you, but of a much higher quality for the needs of a Prius.

 

At 10 volts the battery definitely needed to be replaced.

 

jr stated a light was left on overnight, which discharged the battery, but not completely. personally, if a light was left on overnight, but didn't completely kill the battery, I would think it could be charged. Charging an AGM at 2 or 3 amps takes a little while. Replacing it doesn''t. I'm betting the dealer just said the heck with it and just wanted to replace it, whether it would have charged or not. If it was the original 2012 battery, it was coming due anyway. Just a little harm, just a little foul.

 

Typically CCA ratings for a battery are very conservative. I measure my current battery with a Solar BA5, the CCA is well above rated. The OEM battery, installed new in November 2010, I retired about 3 years back. I've kept it around, not sure why now, and very occasionally hook it up to a smart charger. It still shows CCA almost but slightly lower than spec.

At rest voltage for a decent battery that's sat overnight, in a car that's getting near daily use: good would be 12.6~12.8 volt. If the car's getting more sporadic use, and/or the battery's getting on, you'll get 12.4~12.6. Anything lower is not good.

So yeah, 50 CCA and 10.33 volts is very dead.

This was the original battery by the way? If so, it's a good time to replace, even if it was in better shape, because it won't last much longer: timely replacement will prevent you being stranded at inconvenient times/places.

 

It doesn't "need" to be any such thing.

The voltage at any one measurement can vary due to all kinds of things.
No need to worry until it reads less than 12.5 on several readings.

 

Probably true.

But just ONE episode of dragging it down to 10.5 might not mean certain death.

The story from the shop is BS.
It certainly could have been charged and re-tested.
It might have still failed.
It might have lasted for years......or months......or weeks.

If it was more than 3 years old, replacement was a good move.
If younger than that, I would have charged it first.

While CCA is not really a critical factor for a battery in a hybrid car, all of the shop equipment is calibrated to show CCAs......and bad is still bad, no matter what unit of measure you are using.

 

You can't even do basic maintenance on your car, so you probably don't even own a multi-meter, let alone how to use it to test 12v battery voltage. Direct experience with 12v batteries is much different than repeating what someone told you is true.

 

Insult ignored.
FYI.....close to 40 years as a Senior Electronics Engineering Technician.

 

Any time a battery is tested for CCA it has to be fully charged. If it will not charge it is bad.
Checking a battery CCA is a sign of it's health.

 

Dude, this crap needs to stop. I'm seeing you in more than this thread being snarky - and it's not needed. You may not like him, but you don't have to reply. Use the ignore button. Reporting your posts in the 3 threads I've seen this morning in hopes that this will end.

 

Some people have never had exposure to car repairs. For me it started with me holding the light for my dad when I was a kid and have learned ever since. If you grew up or had no exposure to auto repair your choices are limited. There are a lot of people here that have a problem and a lot of the time they are short on cash and are trying to get the information they need to make an informed decision. At least they are trying to learn. Things are way more complex now than they used to be and there is so much more to learn.

 

Sam Spade 2 has a well established reputation of not treating new people who post on here in a respectable way... He even had to change his name by adding the 2 because he lost his last account.

When you're trying to help someone with a broke down car who can't afford to spend lots of money and they're stressed out and he chimes in the results are incredibly discouraging and unfair. At first I just put up with it and tried to relate to what he was saying, thinking maybe he had some knowledge or experience that would be of value. But yesterday he revealed quite the opposite about his skills and experience. And quite frankly there's no way to tell brand new posters to ignore his comments, so it needs to be pointed out and will continue to be pointed out to the point that it is necessary to help new posters better understand. If the thread is just a bunch of regulars who already know about him then I agree with you, it's easier to ignore him.

 

There's no issue with me in regards to what you're saying... I totally agree with you... The issue I have is when "people here that have a problem and a lot of the time they are short on cash and are trying to get the information they need to make an informed decision" Sam Spade 2 will troll them and tell them they're wasting their time and they need to spend thousands of dollars instead of a less expensive fix. And if he had the skills and experience to back that up his claim his perspective would be valuable. But yesterday he revealed that he's the equivalent of you holding the light for your dad while acting like you know more than your dad about fixing the car. That's not helping people, that's hassling people. When people have a broke down car and are stressed out let's do all we can to help them, not hassle them.

 

Once you say something that raised the hair on their neck up they don't come back.

 

An absolute distortion of the truth.
Quite the opposite is true, in fact.
I have often advocated for checking the simplest and cheapest fixes first.

And I never insult people in the process of giving advice......unlike you who can't seem to stop yourself from continuing an unwarranted rant of insults.

I hope you get help for your rage. It can't be healthy.

 

Hopefully it’s ok to ask a question in a reply thread on this same topic?! My mechanic just said my CCA was 2.5 and that I should replace the battery (out the door he quoted me $270).

The battery costs $191 (price matching local Toyota dealer) and he’s charging $79 for service.

Does that all sound right and fair?

 

CCA should be at least 300 for the OEM battery, if I recall correctly. I remember having a heck of a time trying to find the OEM battery CCA spec, wandering around Yuasa website. I think I ended up guessing 310?

A typical, healthy battery will read well above the spec'd CCA. A borderline battery would read 25~50 below CCA. 2.5 is basically toast.

That price is "ok", not fantastic, but he's got to make a living. It'll take him about 15~20 minutes, fwiw. You can get the Bosch battery at Pep Boys sometimes for around 150 US, and they'll install for free. But you don't want to mess around, I understand.

 

The stock SKS model prius 12v battery rated CCA is 325. A new one will test around 450-475 with my OTC electronic tester. My battery is around 4? years old and still tests around 375-400.

the number 2.5 makes no sense, as any electronic tester would never be able to get to the load test if the battery were that weak.

First test is checking battery voltage and deciding if the battery needs to be charged.
Second test is to look for a failing internal cell
Third test is the load test to determine real time CCA

As for jr in post #17, if I tested my battery and it showed 208 CCA, I would 100% start keeping my eyes open for a reasonable deal on a new battery. That battery is on the edge of leaving you stranded. A $200 battery now beats the heck out of a $200 tow and then a $200 battery.