SIGforum
Oh, Great Knows-All Sigforum Members: Automotive Battery Question

This topic can be found at:
https://sigforum.com/eve/forums/a/tpc/f/320601935/m/2080077815

December 25, 2025, 02:19 PM
PHPaul
Oh, Great Knows-All Sigforum Members: Automotive Battery Question
The trusty Cabota, which will be 11 years old in April, is on the verge of needing a new battery.

The OEM Yuasa is NLA, at least locally. Best I can determine it's a 51R (Group 51 with ground on left)

I'm not averse to spending what needs to be spent but I see WalMart batteries are significantly (~$100) cheaper than the NAPA equivalent.

Is this a case of "Ya gets what ya pays for" or are they (as I've heard rumored) actually pretty decent for the price?




Be careful when following the masses. Sometimes the M is silent.
December 25, 2025, 02:20 PM
RogueJSK
Walmart's Everstart batteries are some of the best bang for the buck in the battery world.

I typically get the Everstart Maxx.

There are only like 2-3 traditional lead-acid automotive battery manufacturers that supply nearly all the batteries in the US, with the ones at the automotive supply or big box stores generally being made by either Johnson Controls/Clarios or East Penn.

So if the specs are comparable and they came from the same factory, the price difference between different batteries from different places is just down to the brand/marketing/store markup. There can often be a $50+ difference between identical batteries that rolled off the same production line, just due to being sold at different stores with a different sticker on them. Go with whatever's cheapest with the specs you want.
December 25, 2025, 02:28 PM
PHPaul
quote:
Go with whatever's cheapest with the specs you want.


Aligns with my thinking. The $150 WalMart battery is actually a bit more robust than OEM, 550CCA vs. 430CCA.

Barring evidence to the contrary, I suspect I'll be hitting WalMart tomorrow.




Be careful when following the masses. Sometimes the M is silent.
December 25, 2025, 02:37 PM
c1steve
Actually there are quite a few independent, small battery manufacturers in business. The one I use has two owners with zero employees. Super high quality, and a very good value.
One general way to gauge what you are buying is to lift the battery up. The heavier battery will almost be the better battery compared to lighter ones.


-c1steve
December 25, 2025, 02:41 PM
smlsig
quote:
Originally posted by RogueJSK:
Walmart's Everstart batteries are some of the best bang for the buck in the battery world.

I typically get the Everstart Maxx.

There are only like 2-3 traditional lead-acid automotive battery manufacturers that supply all the batteries in the US, with most being made by either Johnson Controls/Clarios or East Penn.

So if the specs are comparable and they came from the same factory, the price difference between different batteries from different places is just down to the brand/marketing/store markup. There can often be a $50+ difference between identical batteries that rolled off the same production line, just due to being sold at different stores with a different sticker on them. Go with whatever's cheapest with the specs you want.


This!
My F-350 diesel is very hard on batteries and usually only get about 4 years on a set. With these I’ve been getting 5-6.


------------------
Eddie

Our Founding Fathers were men who understood that the right thing is not necessarily the written thing. -kkina
December 25, 2025, 02:53 PM
.38supersig
Can't really speak positive about anything from CRAPA.

The Optima battery that I have in my truck is two years older than your tractor.




December 25, 2025, 03:19 PM
tatortodd
quote:
Originally posted by PHPaul:
quote:
Go with whatever's cheapest with the specs you want.


Aligns with my thinking. The $150 WalMart battery is actually a bit more robust than OEM, 550CCA vs. 430CCA.

Barring evidence to the contrary, I suspect I'll be hitting WalMart tomorrow.
Biggest thing is to check out the date code and make sure you're getting a battery less than 6 months old as beyond that you're eating into total battery life. Per Consumer Reports:
quote:
A battery made in October 2025 will have a numeric code of 10/25 or an alphanumeric code of K-1. “A” is for January, “B” is for February, and so on. (The letter “I” is skipped.)




Ego is the anesthesia that deadens the pain of stupidity

DISCLAIMER: These are the author's own personal views and do not represent the views of the author's employer.
December 25, 2025, 03:37 PM
PHPaul
quote:
Originally posted by tatortodd:
Biggest thing is to check out the date code and make sure you're getting a battery less than 6 months old as beyond that you're eating into total battery life. Per Consumer Reports:
quote:
A battery made in October 2025 will have a numeric code of 10/25 or an alphanumeric code of K-1. “A” is for January, “B” is for February, and so on. (The letter “I” is skipped.)


Good to know. Thanks.




Be careful when following the masses. Sometimes the M is silent.
December 25, 2025, 03:56 PM
h2oys
We’ve had great luck with the Walmart batteries and consumer reports rates them highly as well.
December 25, 2025, 03:58 PM
shovelhead
Wal-Mart’s Everstart is good to go. They were labeled previously as manufactured by Johnson Controls but since they were bought up by another company they are now under that name. I presently have two, one in my daily driver Wrangler and one in my 67 Pontiac.


-------------------------------------——————
————————--Ignorance is a powerful tool if applied at the right time, even, usually, surpassing knowledge(E.J.Potter, A.K.A. The Michigan Madman)
December 25, 2025, 04:01 PM
Mr.Brooks
Project Farm did a comparison test on auto batteries some time ago. The Walmart batteries came out near the top, and IIRC were considered the best value.
December 25, 2025, 04:16 PM
flesheatingvirus
Agreed on the Walmart batteries. I've been very impressed with the Maxx. I had one in an old truck that looked like it was about to disintegrate- still cranked every time.


________________________________________

-- Fear is the mind-killer. Fear is the little-death that brings total obliteration. I will face my fear. I will permit it to pass over me and through me. And when it has gone past me I will turn the inner eye to see its path. Where the fear has gone there will be nothing. Only I will remain. --
December 25, 2025, 04:24 PM
architect
Could somebody knowledgeable speak to the relative merits of the various battery types for typical automotive use, AGM vs. SLA vs. "wet" vs. gel, etc.

It seems like the battery industry is hesitant to provide their customers with real comparison data (as opposed to marketing speak).
December 25, 2025, 05:51 PM
trapper189
Gel cells aren’t used in cars. They used to be popular in boats because they held up better to vibrations, don’t leak if the housing cracks, can be mounted in a variety positions, and don’t require maintenance (adding water periodically). They are a different battery chemistry and require chargers set up with the correct charging curve for them.

Wet, SLA, and AGM all have the same battery chemistry. SLA and wet cells have lead plates suspended in sulfuric acid. Wet cells need water added periodically and have to be mounted with the openings up. SLA are wet cells that are sealed, don’t lose water, can be mounted on their sides, but will leak if the housing cracks as will wet cells. Neither are particularly resistant to vibration.

AGM, absorbed glass mat, are SLA batteries with glass mat between the lead plates. This makes them more resistant to vibration than wet cells and SLAs. They don’t leak if the housing cracks. The lead plates can be thinner than SLA and wet cells because of the extra support the glass mat gives them so more plates can be used in each cell giving surface area and thus more cranking power. They can be charged a bit faster because the acid is held in place by the glass mat. With SLA and wet cells, the acid has to mix as it’s being charged. Charge it to fast and they give of hydrogen. I’m not explaining this part particularly well because I don’t know the correct terminology.

I buy the AGM batteries for the boats, ATVs and, PWC because they handle the beating better. I buy the WalMart AGMs for the cars and trucks for the 4 year replacement warranty, non-prorated. They last a little over three years, then I get free replacements so a little over six years. The regular batteries with the 3 year replacement warranty also last a little over three years, but then I’d have to pay full price to replace them. Heat kills them just the same.
December 25, 2025, 06:14 PM
iron chef
We had a thread on this recently. I among many other SF members recommend Walmart's EverStart batteries.

https://sigforum.com/eve/forum...935/m/6820024815/p/1
December 25, 2025, 07:05 PM
architect
OK , so I did a little Wikipedia research and found this little gem on the page about Peukert's law.

"For different lead–acid rechargeable battery technologies it generally ranges from 1.05 to 1.15 for VRSLAB AGM batteries, from 1.1 to 1.25 for gel, and from 1.2 to 1.6 for flooded batteries. The Peukert constant varies with the age of the battery, generally increasing (getting worse) with age."

WRT gel batteries not used in cars, aren't the Optima brand gel cells?

So it appears that AGM batteries have significant advantages over other technologies, not only being more durable in crashes, but also lasting longer, and delivering more "juice" out of the gate.

Last time I bought a battery (April 2025) I could not find an AGM in my car's size, except from the VW dealer which wanted over $500 for the item, and a like amount to install it. I declined their generous offer and installed a retail SLA battery of the correct size myself. The same dealer told me that my self-installed battery "failed testing" in June 2025, I'm guessing because it didn't have a VW on the side.
December 25, 2025, 07:26 PM
trapper189
quote:
WRT gel batteries not used in cars, aren't the Optima brand gel cells?

AGM, I believe the first manufacturer of AGM batteries. Theirs are spiral wound hence the six pack shape of their cases.

I read something about the German cars needing their computers fiddled with after a battery change. I don’t know anything more than that yet. I expect I’ll have to learn when the GLI Autobahn needs a new battery. The 2018 Beetle didn’t complain when I replaced its battery.
December 25, 2025, 07:40 PM
nhracecraft
^^ The charging profile for an AGM Battery is supposed to change over time in order to maximize the life of the battery. The 'main reason' you're supposed to program the computer with the code for the replacement the battery is to reset the charging profile for a 'new battery', though various manufacturers do specify slightly different charging profiles for their batteries. This is also the reason why you should generally not install AGM Batteries in cars that were originally equipped with SLA Batteries, and vice versa.

The car won't care if you don't enter the code for the new replacement battery (or know that it was replaced), but it 'could' affect the life of the new battery.


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December 25, 2025, 08:04 PM
trapper189
quote:
The charging profile for an AGM Battery is supposed to change over time in order to maximize the life of the battery.

Same is true with regular wet cell and SLA batteries; the curve is different for AGM.

Three phases for smart chargers: bulk, absorption, and float. During the bulk phase, the charger throws as many amps as it’s capable of at the battery. IE, a 15 amp charger throws 15 amps at the battery. As this happens, the battery’s voltage rises until a preset limit. The limit is different for different batteries. Don’t quote me, but I believe 13.8v for gel, 14.4v for wet cell lead acid, and 14.7 for AGM. The batteries reach this preset limit at about 80% of fully charged. At this point, the absorption phase, the charger holds the voltage constant by reducing the amps it throws a the battery. Once the battery is fully charged, the charger goes into the float phase where it just keeps the battery charged and reduces the charging voltage, about 13.2v for a wet cell lead acid battery.

Cheap chargers let the voltage keep rising which cooks the acid and water releasing hydrogen and destroying the battery. There’s more, like temperature compensation, but I see eyes glassing over already.
December 25, 2025, 08:09 PM
John Steed
WalMart EverStart Maxx.

I had one in the Jeep for years. I later replaced it with another one of the same, not because it was failing, but because at the time I had a long commute and with winter coming on it seemed prudent to install a new one.

I see from my records that I had that second one for about seven years when I decided again to not push my luck so got a third one in 2021. That's the one in it now. On the coldest days, it starts right up.



... stirred anti-clockwise.