Replace OEM 12V battery with Group 25 AGM

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

 

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?

 

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.

 

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...

 

Spend the $55 on a smart charger, and/or an electronic load tester.

 

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.

 

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.

 

Maybe technical difficulties at your end? What are you posting on, phone, Windows PC, MAC?

 

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?

 

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



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:



To try a quick experiment:

1. Type "Snipping" in the search bar:



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



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.

 

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.

 

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.

 

Great prius v info on gen 3 section.

 

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!

 

I am planning on putting a bigger (60 ah) battery also in my car but I was wondering if there is a long term danger for damage to the charging circuit of the inverter.
I read it is capable of delivering max 120amp but still since my electrical knowledge is limited I wonder how harmful will be to have a 60ah or bigger battery which from time to time will discharge near 12volts or less and then having the inverter charge this battery during driving back to full.

 

Thanks everyone for this thread! Very interesting. I have a 2012 OEM battery that's tired and won't hold the full charge, choosing to sit around 12.3 in above-freezing winter temps. I'm thinking of a U1 tabbed 35AH AGM battery from Harbor Freight with the U1 to SAE/DIN kit one can buy on ebay. Because of that I will be buying elearnaid's nice kit that changes the car side terminals from JIS (the small posts temrinals) to the SAE that my modified Habor Freight battery will be offering.

My question is: with AC/DC inverters attached to the aux battery, what/how much negative effect will I see against the new 35AH battery versus the old 45AH OEM battery - this is about a 20% capacity loss.

Also, of course the Harbor Freight battery isn't set up for the venting tube. Since all these AGM batteries actually have a little compartment that vents through 6 little 'spill proof' holes under a long black cover, can people who've added venting to a battery please comment how they did it?

Thanks

 

I completely support fiddling in the back passenger little hell hole to get a cheaper than OEM battery in there - heck, it's a great time to also make sure no water's getting in / clean out the rust and junk under the battery. I'm on this journey too at the moment.

Just in case anyone read your above comment and wasn't sure, I'd suggest people NOT get anything other than a gel or AGM or 'deep cycle' battery for the prius - the car doesn't need a traditional 'starting' type battery and the charging system isn't set up to work with that kind.

The concern about a battery in the rear corner inside the cabin is real: when a battery is stressed (too much charging, too much discharging etc) it is in the 'error condition' which will cause it to vent. The gasses aren't good and are explosive. As long as you never use an inverter or overcharge or overdraw, I guess you can rely on the nearby HV battery vent, but for folks dabbling in battery replacement, perhaps they want to take the time to do it right.

Another thing about the back of the car: this is where collisions are likely. Be careful to buy a battery that has the positive terminal far from the metal wall of the car.