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Read This Before Buying A New 12V Battery For Your Toyota Prius

If you are needing a new 12v battery for your Toyota Prius, here are a few helpful hints to ensure you are getting the best deal and warranty.

Hey everyone! I wanted to give you a cool tip for the day if you are looking to replace that old 12v battery that is in your Toyota Prius. If you want some more information check out my other article here that talks more specifically about which battery to choose and why.

I recently bought a 2010 Toyota Prius to work on, and I am hoping that I did not make a mistake in doing so. The car for sure needs a head gasket repair and maybe a whole engine. We will see what happens when I get the head off of it.

For me to work on the car, I needed to replace the 12v battery that was four years old at this point. It would no longer hold a charge, and it would not even take charge when I put it on my battery conditioner. Doing this process is different than reconditioning a hybrid battery just so you are aware.

It was failed and I need a good power source to be able to move the Prius around in the shop while I work on it. I pulled out the old battery and decided that I would try and get it warrantied. Here is what I found out.

What A Battery Warranty Is
A battery warranty is saying that if you purchase this battery from the XYZ auto parts store, they will guarantee it to work for the specified time that is stamped on it. In my case, the "warranty" was for 75 months on this particular battery.

All battery warranties vary by the auto parts store or dealer that is selling them. Remember this, not all battery warranties are created equal, and I will explain why in just a moment.

I was excited that I may get a free battery to put into this car, which would help reduce my overall cost of ownership and get me what I need. Oh, how wrong I was.

My Friends At The Auto Parts Store
Because of who I am and what I do outside of automotive journalism, I do automotive repairs. Over the years, I have gotten well acquainted with many auto parts stores, the owners, and also the staff. My favorite place to go is NAPA.

Typically they give me a great deal, and they are easy-going. In this case, I also chose them as the battery was a NAPA Premium Legend, the cream of the crop, so to speak. I was hopeful that I could swing a deal with them and walk out without paying a dime. Nope, and here is why.

Not All Battery Warranties Are Created Equal
All batteries have different tags on them to signify when they were manufactured. They also have quite a few different ways of figuring out (when there is no receipt) to know when the battery could have been purchased. For instance, this picture below shows month and number dots that are supposed to be removed when the battery was sold.

Toyota Prius 12v battery sell date for warranty

In my case, the markings on the old battery would have signified that the battery was purchased in 2016, not bad there still should have been a warranty on it, right? Hardly. Here is what my friends enlightened me on. This second picture you see is also an indication of when the battery was manufactured—another clue they use to determine when it was purchased. My old battery had a 4/16 tag indicating it was produced in April of 2016.

Toyota Prius 12v Battery Manufacture Sticker

All of the major auto parts warehouses like Autozone, O'Reilly's, NAPA, Advanced auto, and others have figured out that selling batteries can cost them or make them significant dollars depending on what they are offering the consumer. At this point, my hopes of getting a "free" battery went south.

All of these places offer a warranty, but you need to read the fine print to know what you are getting. Most warranties will cover the full cost of replacement of the battery but only for 18 to 24 months.

That means my Premium Legend battery that has a 75-month warranty on it has to take a pro-rated warranty, which devalues the battery every month until that period has expired. But wait, there is more.

What if you swap out your battery every 18 to 24 months, then claiming it has "failed"? Nice try, but these guys thought of that trick too. You see, when you buy a new battery, the warranty is to cover a possible new battery. It is not a recycling program that you can keep exchanging batteries.

That means if your battery goes dead at 18 months and you get a full replacement, that is it, you get nothing but a pro-rated warranty after that for the remainder of the days of the battery. So my super, duper impressive battery that was still under warranty ended only giving me $6.25 worth of credit, and that was because the guys were helpful.

Getting The Best Deal On A Prius Battery
I am loyal to NAPA but usually, it is because they give me the best price. I still price shop them though. To get the best deal, call several places and see what those prices are. That is also a good time to ask them about what their warranty covers specifically.

If you have a favorite place as I do, call them up, and tell them you found it cheaper. Most auto parts places are more than willing to price match, especially in this economy.

Most of the time you can expect to spend about $250 for a new 12v Prius battery. Anything better than that is a pretty good deal. Taking the time to call around is your best friend, and we all know that time is something we have right now.

If you need a new battery for you, Prius, to be sure you understand what the actual warranty entails. I have heard that Costco batteries are a good way to go and that they start the warranty period over even if you exchange a dead battery. I have done this on my mom's Lexus, and that is what Costco told me.

The 12v is going to be expensive no matter what, so help reduce that cost and find which one has the best warranty before you buy it.

I hope you are all safe and healthy out there. If you want to know something, drop me a line on Twitter @the_hybrid_guy or even shoot me a message on Facebook. I am always willing to help a fellow Prius owner get the most out of their hybrid.

I look forward to seeing you in the next story. 3 Signs You Have A Bad Head Gasket In Your 2010-2012 Toyota Prius.

Watch this Toyota Prius truck with a nice little bed and click to subscribe to Torque News Youtube for daily automotive news analysis.

Peter Neilson is an automotive consultant specializing in electric cars and hybrid battery technologies. He holds a Bachelor of Science in Automotive Service Technology from Weber State University. Peter is also an Instructor of Automotive Technology at Columbia Basin College. Peter can be reached on Linkedin and you can tweet him at The_hybrid_guy on Twitter. Find his page on Facebook at Certified Auto Consulting. Read more of Peter's stories at Toyota news coverage on Torque News. Search Toyota Prius Torque News for more in depth Prius coverage from our reporters.


David Bonacci (not verified)    April 3, 2020 - 12:45PM

Thanks for the battery info.
My 2010 Prius, purchased new in August of 2009, is still on the original 12V battery. The car is about to turn 112000 miles.

Alan (not verified)    June 24, 2020 - 9:28AM

Out of curiosity, I asked at Costco about a 12v battery for a 3rd-genration Prius -- a Group 51 battery -- and they told me that they do not carry them and cannot special-order them.

alain (not verified)    April 18, 2022 - 12:12AM

In reply to by Alan (not verified)

that is correct, Costco (best place) only carry regular group 51 (not AGM nor vented) bummer as they are $80 vs ~$200. Found the Interstate AGM at Napa for $150 after rebates, but won't be costco warranty nor price :(

Alex (not verified)    August 25, 2020 - 6:16PM

I have a 2015 Prius 2. with 152K miles on it, and my 12V atill works fine. Just had new brakes rotors and pads installed for the first time a few weeks ago.
Best car I've ever owned.
+ the parts and labor are really affordable even at the Toyota dealership.

Ulev (not verified)    January 3, 2021 - 8:08PM

I had the very same battery experience with my 2010 Prius III.purchased Sept 15,2009...The 12 v battery lasted over 10 yrs..
Till yesterday...left my new Z cam up and evidently drained the venerable 12 v. Over several days outside in intemperate weather...
I thought I saw a Prius 12 v battery test, by using internal available dash
Bit different for 2010 models, anyone have a hint to where it may be found ?

Richard Dale (not verified)    August 20, 2021 - 8:16AM

We have a 2018 Prius Plus and since it was new, whenever we leave it idle for a couple of weeks (like airport parking lots), the 12 v. battery runs down. Is there a solution?

Panel Hartman (not verified)    July 5, 2022 - 1:57PM

Having problems starting my 2014.5 Canty Hybrid lately on days I don't drive more than a mile each way to work. I jump start it easily but wondering at 66k should I be replacing it? If so with what type? Owhere manual doesn't state and I don't trust dealership. Please help me !

Thomas Francl (not verified)    December 9, 2022 - 3:26AM

2017 Prius Hybrid. Need to replace the 12v battery. AAA road tech told me that they no longer replace them because of problems. He said there is a dependency between it and the big battery. He wasn't real clear, but said the big battery had major issues if disconnected from the 12v battery. I can't believe that I must have the dealer do the replacement.

CLAIR KRAFT (not verified)    January 13, 2024 - 1:35PM

In reply to by Thomas Francl (not verified)

You can leave a jumper wire on your positive side of your battery terminal and avoid problems and losing stored memory on your car. I hooked up my positive charger clip to the positive battery cable and switched the battery out.

Gus Munguia (not verified)    February 28, 2023 - 7:44PM

2014 Prius. I went to Interstate Battery to buy a replacement 12 volt battery, I was told it's a dealer item they only sell to dealers otherwise they loose the contract, patent rights have not expired I was told. I find it hard to believe only the dealer can replace this battery $$$.