Should I return this EverStart Platinum battery, or put it in service

[SubLGT]

Will a 24F fit? Its 1.25 inches longer, the other dimensions are the same. Around here they seem to have a lot more 24F stock.

No, too long. No urgent need, I can wait for a 35 to come back into stock.

 

[M1Accord]

Is Cayman as in a Porsche? If so, very nice brother.

As my personal rule, I don’t return battery unless it is defected. If I find a better price locally, I’ll see if I can get price matching but as I get battery from Wally or Costco, I doubt there is better price around.

The reason I don’t return batteries is that I think people shouldn’t be returning those things, which have to be put back on the shelves and if it was either used or misused unintentionally, the next person is essentially paying new price for a used battery. I know my logic isn’t flawless but it is my rule and I tend to research the things I most hesitant to return very carefully before the purchases.

So yeah, I would exchange for a fresh battery and do the check at the store to get the battery with the tested CCA you expect. The last time I bought battery because the car kept not starting or rev high at idle, I brought my multimeter and tested their battery right there at Costco. That didn’t solve the problem so it wasn’t the battery but I kept it anyway and used the order battery as a jump box.

 

[JimPghPA]

Double post, deleted.

 

[JimPghPA]

Are you connecting your battery tester directly to the Post of the battery, or are you connecting it to a connector that is connected to the battery or even worse to a cable at a distance away from the battery. You should realize that we're talking about mili-ohms here. As in 1/1000 of an ohm, as in 0.001 ohms, or in the case of a reading of 4.7 mili-ohms that would be 0.0047 ohms.


If you're measuring it after a connector that is not an extremely good connection you could add enough resistance to drastically throw off the reading and also drastically throw off the cold cranking amps that the battery tester is indicating. When you're dealing with 760 Amps every 0.001 ohms of resistance adds 0.760 volt drop.

0.0047 ohms at 760 Amps will cause a 3.572 volt drop if the battery tester actually loaded it down with that much current. In reality the battery tester calculates the internal resistance of the battery by extrapolating from a curve created by taking measurements with different amount of current being drawn from the battery but nowhere near the actual cold cranking amps.


Small amounts of resistance are really a super big deal and can drastically throw off a battery checker if you're not directly connected up to the terminals.

The temperature that the battery is at will also affect the cold cranking amp rating and the internal resistance a little bit. If it's extremely cold then you'll see a significant decrease in cold cranking amps.

A brand new battery should measure more than 25% greater than the actual cold cranking amps ready. But that's when you're connected directly to the post on the battery and it's fully charged.

I bought a brand new Walmart MAXX 24F on 9/17/2033 and it had a 9/22 sticker on it and I tested it in the store before I bought it. Rated 725 CCA test showed 1,117 CCA


Since then I've been testing it in my car but connecting up to the vehicles connectors that are on the post and not actually on the battery post and there is a slight reduction of CCA immediately from what I was getting in the store because of the added resistance.

The following are the cold cranking amps readings that I have taken on that battery since I purchased it but these are all connecting up to the vehicles connector that are connected to the battery post (though mine are heavy duty after market and very clean and kept from any corrosion by being sprayed with Corrosion X Aviation grade. Not actually to the post of the battery.

Note, Bat temp taken by using an ir temp gun aimed at the top of the bat.

CCA 1040 11/27/22 Bat temp 57.5F 3.07 m ohms
CCA 948 2/4/23 Bat temp 25.5F 3.36 m ohms

CCA 1060 6/17/23 94.0F 3.03 m ohms

CCA 1010 12/2/23 Bat temp 72.0 F 3.16 m ohms

CCA 871 1/17/24 Bat temp 10.5F 3.64 m ohms

So you see, even after being a year old it tests significantly above it's rated cold cranking amps even when it's pretty cold.
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OP, if you are actually connected up to the post to the battery you and have good clean connections and the readings are that high for the mili ohms (4.7) for a new battery it is definitely a bad battery.

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When I tested the battery in my brother-in-law's Jeep I tested it first by using the jump connections under the hood, and the battery is located inside the vehicle under the front passenger seat. The cable connection between the battery and the jump connection under the hood was quite a lot of resistance and drastically through off the reading and the battery tested bad, but when I tested it on the post of the battery it tested good. You should realize that I am talking about an adding of a small amount of resistance that can throw off a battery testers reading significantly.

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By the way, the proper notation when you're dealing with mili-ohms (1/1000 of an ohm) is a prefix of a small m. Proper notation when you're dealing with Millions of ohms (1,000,000 ohms) is a prefix of a large M.

The difference between using the small m and the large M is a factor of a billion, so using the incorrect prefix is really a pretty big deal in getting something written down correct or wrong.

I get a kick out of reading a prescription bottle when the prescription is for milligrams and they use a Big M. They're actually notating it on the bottle for Millions of grams with their improper notation so their notation is only off by a factor of a billion, LOL.