Replace OEM 12V battery with Group 25 AGM

Discussion in 'Gen 3 Prius Accessories and Modifications' started by cproaudio, Jul 9, 2015.

  1. mrstop

    mrstop PWR Mode

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    It looks like there is a new lower cost group 25 replacement from Pep Boys under the Champion Brand. It is normally $159.99, but right now it is $119.99 core and 25% off online ordering (ebates gives another 3% rebate). I took a look in the store and it appears to be manufactured by Johnson Controls. There is a port on both sides which looks to connect to our vent tubes. I couldn't find a great deal of information, but it uses a stamped grid system rather than the Optima Spiral technology. I'm not sure about country of origin, but apparently Johnson Controls has invested to increase AGM production in the US and China over the past couple of years.

    Reserve isn't quite as robust as the apparently discontinued Exide, but still more than the factor replacement and on par with Optima or Odyssey.

    Specs:
    Height (in.) 8.88
    Cranking Amps @ 32F 685
    Terminal Type A
    Width (in.) 6.94
    Reserve Capacity (minutes) 100
    Length (in.) 9.06
    Group Size 25
    Voltage 12
    BCI # 25
    Weight (lbs) 40
    Height (mm) 225
    Length (mm) 230
    Right Or Left Hand Positive Right
    Cold Cranking Amps (CCA) @ 0F 550
    Width (mm) 176
    Wet or Dry Wet
     
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  2. MattFL

    MattFL Member

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    What brand/model is currently the best (or among the best) AGM replacement for the 12v battery? Reading the Optima reviews on Amazon it seems they have an extremely high early failure rate and horrible warranty support, so it looks like their quality is not what it used to be. Is OEM the best choice at the moment?
     
  3. mrstop

    mrstop PWR Mode

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    The Champion worked fine if you have a Pep Boys near you. Only had it about a year, so I don't know about how well it will hold up long term.
     
  4. MattFL

    MattFL Member

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    Thanks for the reply. The Pep Boys web site won't show me the champion, only the optima, maybe I have to go in the store to see it. I found an AC Delco model ACDB24R on Amazon with tomorrow delivery for $165 + tax that got good reviews, the local dealer wants full retail ($217 + tax) for the OEM battery. Reading the reviews online, it seems battery warranties are worthless if bought online, so I'm debating if it's worth $55 for a really good warranty vs. no warranty...
     
  5. Mendel Leisk

    Mendel Leisk 'Orrible Oracle

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    Spend the $55 on a smart charger, and/or an electronic load tester.
     
  6. 2012 Prius v wagon 3

    2012 Prius v wagon 3 Junior Member

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    I swapped an Optima Red Top 34/78 from another car into my 2012 Prius v, working just fine. I know a yellow or blue would have been better, but I already had this red in my garage queen 911 and thought I'd see if it helped my Prius. BTW, the Prius battery can start my 911. LOL

    The fit is very snug, with a few cardboard pieces around it. The bracket over the top is connected only in the front, not in the rear, and that receiving piece (tray, etc.) was removed (and saved, of course). Given how snug the overall fit is, and being held by two cables, I have no fear of the battery moving anywhere in a crash, even with the rear (outboard) end of the bracket not connected.

    Cables required a little work - swapped in an SAE negative cable. Positive SAE clamp, with a little customization required since the post is further in-board than on the Prius battery.

    Regarding vent tubes, Optima confirms that they do not typically vent, as some do. They only vent in a fault condition. I used some hose to build a custom manifold feeding both vent outlets from the battery to the Prius hose exhaust.

    Anyway, so YES, my Optima Red Top 34/78 fits like a glove.
     
  7. cproaudio

    cproaudio Speedlock Overrider

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    Would love to see pictures of the battery installation on the Prius V.
    As of now, the only group 25 AGM battery around is the Odyssey group 25 which has similar capacity as a group 24F. Odyssey confirmed that their batteries are safe for in cabin install without vent.
     
  8. 2012 Prius v wagon 3

    2012 Prius v wagon 3 Junior Member

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    I'm not sure what the threshold is before I can post pics, but last time I tried, whatever it is, I'm below it. PM me, and I'll try to message you a photo so you can post, if you want.
     
  9. Mendel Leisk

    Mendel Leisk 'Orrible Oracle

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    Maybe technical difficulties at your end? What are you posting on, phone, Windows PC, MAC?
     
  10. 2012 Prius v wagon 3

    2012 Prius v wagon 3 Junior Member

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    Win10, Chrome. But I am running adblock plus - could that be it? I just assumed that I was being limited for being new, never tried to work around. So are you saying it should work?
     
  11. Mendel Leisk

    Mendel Leisk 'Orrible Oracle

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    When you're in the text editor, composing a message, do you see the "upload a file" button?

    upload_2019-11-28_9-52-18.png

    If so, click on it, navigate to your image pile, select it and click ok. Then the image should be attached. You can also place the image within the posting, by positioning the cursor where you want the image, then clicking:

    upload_2019-11-28_9-54-40.png

    To try a quick experiment:

    1. Type "Snipping" in the search bar:

    upload_2019-11-28_9-46-55.png

    Click on the Snipping Tool app (should be first result.

    upload_2019-11-28_9-47-56.png

    Click "New" in the app. Then click-and-drag across a rectangular area of your screen, to take a snapshot of it. This will put the image in Windows Clipboard (on deck, so to speak).

    Now commence a new post in this thread, locate the cursor and type [ctrl] V. It should "paste" the image where the cursor was.

    Click the "post reply" button and see how it goes.
     
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  12. 2012 Prius v wagon 3

    2012 Prius v wagon 3 Junior Member

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    That's what I had been doing. I did a quick test just now, without saving, and it looks like it works. Doing nothing different on my end vs. before, so maybe some limiting window timed out. Now I just need to go and take some pics of the battery.
     
  13. 2012 Prius v wagon 3

    2012 Prius v wagon 3 Junior Member

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    Here are the pics for the setup as described above in post #66.

    I know an Optima yellow top would be more appropriate in this application, but I had the Red top in my other car, and figured I'd swap it in. Not optimal. But I think if anyone wants to put a yellow top Optima 34/78 in their Prius v (2012 at least, like mine) it should fit.

    I did not want to push my luck with the old original Prius battery being able to start my other car, so with a great deal at Pep Boys, I bought a replacement AGM group 34 for that car. Specifically, it was the Champion AGM 34-740CHAGM, made by Johnson Controls. Figuring it was the same group size as the Optima 34/78, I tried to see if it would fit in the Prius and ... NOOOOOOOOOO. Although the overall dimensions match with the Optima, it is the curved corners in the Optima due to their spiralcell thing that allow it to fit so well in the Prius. The sharp rectangular corners on the Champion AGM (and I expect any rectangular battery) make it not even close to fitting.

    Summarizing findings here:
    • In my 2012 Prius v (the v is known to have more room back there, I believe) ...
    • Optima 34/78 fits really well, enabled by its rounded corners
    • A rectangular group 34 battery was tested and is not even close to fitting
    BTW, when I built that little adapter for the positive terminal (from 1 mm thick copper sheet), it was just because I wanted to get something built and in there. I have since bought the proper pencil post to SAE post adapters, in case I ever want to re-do that. Cheaper and easier to do it that way if one has the foresight to see the problem with the post being too far inboard.
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  14. Grit

    Grit Senior Member

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    Great prius v info on gen 3 section.
     
  15. cproaudio

    cproaudio Speedlock Overrider

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    I did mention on post # 35 that a larger battery might be able to fit the prius V. I'm just glad that he confirmed it for me.
     
  16. TheBungler

    TheBungler New Member

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    I know this is the 3G section but I found this thread via Google looking for battery options on my 2G, so I figured this would be a good place to post.

    A group 25 does NOT fit a 2g Prius. I tried and it didn't quite fit.

    After going through the Walmart battery rack with a tape measure I found that a group 51 Everstart Maxx is a perfect almost OEM fit. Runs about $110. As mentioned earlier in this thread you'll need a ground cable w/integrated clamp and a US sized battery terminal. I was able to purchase both of these, again at Walmart for under $10 combined.

    I purchased the "Marine" battery terminal and there was a slight compatibility problem. Had to drill out the hole in the Prius terminal a little larger for the bolt to fit through. There wasn't enough clearance for the included wingnut to attach so I had to dig a regular style nut out of the parts bin.

    Other than this, no surprises. Dropped right in.

    Please note that the Everstart is *not* a spillproof AGM battery, and can *not* connect to the vent hose. If you get rear ended there's a possibility it could spray acid everywhere. If your charging system malfunctions there's a possibility it could vent hydrogen gas and cause a small explosion. Given that the battery is fairly well buried and is right next to the rather-drafty vent for the HV battery cooling system I judged these risks to be pretty low. You will want to make your own assessment.

    Hope this is of help to someone!
     
    #76 TheBungler, Dec 20, 2019
    Last edited: Dec 20, 2019
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  17. cproaudio

    cproaudio Speedlock Overrider

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    Group 51 is the SAE version of S46B24R. Pepboy's Bosch Platinum group 51 is the OEM replacement for the Prius. I believe it even has the JIS post for direct fit to the Prius.
    Careful about the Walmart's prorated warranty. The replacement battery takes over the original warranty. If your 7 year battery craps out at year 6 and you paid 80% cost of a prorated warranty replacement, your replacement battery has only 1 year warranty left. If it dies on you on year 2, it has no warranty at all. You just wasted that 80% cost. Learned it the hard way when my replacement battery died after 2 years.
     
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