Battery decision time, 2005 Camry: I am 3.5 years into an Everstart Maxx 24F 750CCA manufactured by Johnson Controls, (1.5 years of proration remaining on the warranty). One cell is bad, as measured by my hydrometer. Battery tests at the auto parts chain stores here in the LA area, at the beginning of the year and today, sometimes say “ok” but sometimes say “bad battery”. Today they measured voltage of 12.34v, 12.5v. The battery has never failed to start the car and never even had difficulty starting the car. I can’t figure out from internet searches what a bad cell really means for the future life of the battery.

I had the battery tested last December by Walmart and they passed it at 12.73v, and 635CCA measured at 68degrees F. That Walmart is 30 miles away, so it got 35 minutes of charging by my still good alternator by the time I got there.
Even after calling Walmart several times, including talking to one of their Auto Service centers, I can’t tell how they determine if the battery has failed, warranty-wise. They might say that since it still starts your car, it’s still good.

I’ve had good luck with Walmart batteries, but they’ve changed their sourcing from Johnson Controls to “made in S. Korea” (no company name listed). The new 24F model is now maintenance-free, and listed as 700CCA instead of 750CCA. It has a three year warranty (replacement), no pro rating period. They dropped the price to $90 on the website, but are still using a picture of the old 24F version. That price is waaaaay under anything else I’ve seen. A lot of stores have been out of stock on them, which makes me wonder if they are closing them out.

Worryingly, the manufacture date stamped into the case of the new model does not seem to follow the usual coding practice, so I can’t confirm that the battery was actually manufactured in Nov 2020, as the sticker claims.

I’ve read that a battery in bad condition taxes the alternator, but I don’t know at what point in a battery’s decline into old age it starts being a burden on the alternator. I still have the original Denso alternator, and it’s more important than any battery.
So do I currently have a good enough battery that could easily last another couple years, or should I get a three-year $90 battery with an unknown manufacture date? Or buy and store a battery until the old one gives out, cuz this is such a low price for a three year battery.

 

Don't buy and store a battery. I would have it tested again next time it's convenient. If they still get around a 500 or 550 cca reading or more I'd continue to drive with confidence. (If the battery were already 5+ years old I'd be more conservative and quicker to replace)

To get an accurate voltage reading I pop the hood after driving it home in the evening. Then go out the next morning and check voltage without opening a car door so no interior lights or anything wakes up causing a current draw. I would hope it reads 12.5 volts unless it's sitting outside in the cold this time of year.

Also if most of your driving is in the city, I believe it is a good practice to put a car battery on a charger a couple of times a year - at a low amp charge rate for a few hours.

Thanks for sharing about the new battery sourcing at Walmart. I've been wondering why their prices have gone down a bit or stayed the same when most of the others are $25-40 more now. I guess we will not know about any quality changes until more time has passed.

 

Battery specification for Camry: 24F and 582 CCA is all required. It may be that the OEM battery is 582 CCA.

 

I live in Louisiana and here O'Reilly Auto Parts has a Motorcraft group 24 AGM battery for only $140.

I just bought a battery and all the other AGM batteries I found were $200 or more.