New battery - tester says "bad"

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So yesterday I turned my car "on" but not started in order to put it into neutral and roll to a clear spot in our driveway so I could wash it. I ended up leaving it "on" - headlights, climate control fan, radio, etc - and killed the battery. Put my Schumaker (8A) charger on it and for ~2 hours it didn't show much progress so I ran to Walmart to get a replacement battery (this battery was 6 years old too). By the time I got home, it had successfully charged, car started, and has started multiple times today. Overnight, I put the new battery on the trickle charger and this morning it was indicating "Bad battery".

Took it to Walmart to return or exchange but they test it and their tester (admittedly, a better one than mine) says it's good. They won't exchange it in this case and said I can take it to the front desk to return, but they'll make me get it tested first and when they're told it's good, they'll refuse the return. My other option is go to a store without an auto center, which I'm considering....

Any ideas why my tester says it's bad but theirs says differently ? The manual for my tester suggests "desulfication" failed. No idea what that means....
 
Can't you just return it and say you bought the wrong one? Then buy another one and go through some other checkout line.

Anyway, I wouldn't trust your tester, just throw a meter on it and see what it says. Or get a real load tester and use that.
 
A dead battery needs like 8 hours to recharge with an 8 ampere taper charger. You were too quick to condemn the battery. Put it back on the charger for 8 hours or more untill it drops to ~ 1-2 amps.ed
 
I HIGHLY doubt a brand new battery is bad. Its possible but I've never seen it dealing with hundreds if not thousands of those Walmart batteries. You could return it and say it wasn't the right one for your car, if you still have the receipt.
 
Did you try testing that suspected bad old battery that still cranking with your load tester?
I am assuming it is a load tester.
 
I have a pretty decent charger that sometimes condems good batteries. I would use a dedicated tester for accurate results and not the one in the charger itself.
 
Originally Posted by hallstevenson
so I ran to Walmart to get a replacement battery (this battery was 6 years old too)... Took it to Walmart to return or exchange ...


Confused here... you took a 6 year old battery, that presumably doesn't have any warranty, to Walmart for an exchange? If that's the case, wouldn't you just buy a new battery and use your old battery as your core, negating the need for the battery to be tested?

If you bought a battery yesterday, and no longer want it, you should be able to just go to the service desk and ask for a refund. Don't mention anything about the battery "testing bad" by your trickle charger. Just tell them you need to return it. That you thought you needed a battery, but found out that your battery was actually good, so you no longer need the battery that you bought.
 
Originally Posted by Wolf359
Can't you just return it and say you bought the wrong one?
Originally Posted by FordBroncoVWJeta
You could return it and say it wasn't the right one for your car, if you still have the receipt.
That's definitely an option because every battery selector says to use a Group 35 but the factory battery and the battery currently installed is a 24F.

Originally Posted by FordBroncoVWJeta
I HIGHLY doubt a brand new battery is bad. Its possible but I've never seen it dealing with hundreds if not thousands of those Walmart batteries.
FWIW, it has a sticker with "11/18" on it. It's a Johnson Controls unit that they're replacing with Exide (in our area).

Originally Posted by JMJNet
Did you try testing that suspected bad old battery that still cranking with your load tester?
I am assuming it is a load tester.
My equipment is a "smart" (trickle) charger. Walmart had a pretty nice tester - it showed 12+ volts sitting on their counter and he did something else that measured "amps" and I could watch it go from 680-something to 780+.

I'm not adamant that my simple tester is right or better than theirs. Just seeing what options I should look at.
 
If the new battery starts the car and the professional tester showed good (presumably 680-780+ amperes), then I'd use the battery and not worry about it. The indicator on the charger is not the cat's meow. It may be a handy guide, but there's more going on than a simple charger can tell you.
 
A "Smart Trickle Charger" is NOT a battery load tester.
I am not sure why the smart trickle charger shows bad, though.

If you have Harbor Freight store, buy one of their load tester and try testing your battery with it.
It is only around $20 and sometimes cheaper with coupon available from their website.
Make sure the battery is fully charged before doing the test.
This load tester is analog with needle and it is not as fancy as WM or part store tester but it works better, IMO.
 
2 thoughts:

1: Walmart does not accept "remorse" returns on batteries. And they are the most lenient on car batteries out of anyone.

2: Let the new battery sit, or take some of the float charge out of it with a pile tester first. When you test it right after it's been on the charger, the algorithm in your tester is getting confused. The reason that walmart's tester probably found it good was because you let it sit off the charger for a bit before testing it. Or their charger actually puts a large enough load on the battery to accurately test.

What tester are you using at home to determine these batteries?

Edit:
I was assuming you were using an actual tester.. HF sells a good smart analyzer, which I've confirmed is ~95% as good as the more expensive ones: https://www.harborfreight.com/digital-automotive-battery-analyzer-66892.html

As a previous poster mentioned, getting a simple pile tester IN CONJUNCTION with the smart analyzer is a good idea as well:https://www.harborfreight.com/100-amp-6-volt12-volt-battery-load-tester-69888-9191.html
 
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A battery can show 12.8 volts sitting there and still be bad. Load test is the only way to tell if battery is good.
 
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Ok so it was dated 11/18.... Sat likely uncharged the entire time... A flooded battery... Flooded batteries lose 5-12% charge per month sitting around uncharged... That means it could have been down a fair amount of charge/capacity... It being charged would help it quite a bit. Though it could be suffering from sulfation due to sitting around that long without any charge applied. That will not be hurting it now but could shorten it's life to a degree at the end.

I would not worry about it now... Just really charge it well now. And try to charge it regularly on a charger. The alternator is not going to bring it any where near one hundred percent.
 
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I would not have bought a new battery so quickly. You need a better battery tester.

But if Walmart will not accept a return, then install it and return the 6 yr old one as core. A 6 yr old battery does not have that many years left.
 
My supposed "smart charger" sometimes reports a good battery as bad simply because the connections to the battery terminals aren't good. Wiggle the connectors a bit and make sure they have a good strong connection. I too recommend keeping the new battery and returning the 6 year old for the core charge.
 
Originally Posted by Donald
I would not have bought a new battery so quickly.

But if Walmart will not accept a return, then install it and return the 6 yr old one as core. A 6 yr old battery does not have that many years left.
I was planning on replacing the battery proactively given it's age. This just pushed me to do it sooner.
Originally Posted by AuthorEditor
My supposed "smart charger" sometimes reports a good battery as bad simply because the connections to the battery terminals aren't good. Wiggle the connectors a bit and make sure they have a good strong connection. I too recommend keeping the new battery and returning the 6 year old for the core charge.
After the first 8+ hour trickle charger, where it showed "Bad battery" after those 8+ hours, I charged it again twice - first time for an hour or so before it reached full charge and flipped to "maintain" mode and again today, I repeated that, but it took less time to go into "maintain" mode. I decided the "Bad battery" indication was a fluke and the battery is installed as of now.

Part of me wants to have this 6+ year old "Infiniti" (dealer-installed) replacement tested to see how it's doing after this many years.
 
A little confusing but what I make out is the old dead battery in the car was eventually revived.

The new battery is labelled as "bad", desulfation, you can have the correct voltage but one or more of the internal plates faulty. Very rare on a new battery. But physical shock or mpoor manufacturing can cause it.

What does walmart use to test the battery? The only way I know of to work this out is to do a CCA test. BTW the old style CCA testers can actually damage the battery, You need an electronic one (very exoensive!)
 
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Originally Posted by bonjo
A little confusing but what I make out is the old dead battery in the car was eventually revived.
Yes, that's correct. I eventually got it charged and it was working fine. To clarify, it was on the charger for 4+ hours and my simple voltage meter was showing 6.xx volts and I figure I killed it good and it probably wouldn't recover. It was also 6 years old so replacing it wasn't a crazy idea. I drove to the store and got a new battery, ran to a 2nd store, and then an errand which ended up taking me ~3 hours. The charger was still on the battery during this too. When I did get home, the voltage was 12+ (I don't remember the number now) and the car started fine. I pulled it into the garage and continued charging it until the charger switched to "maintain" mode.

Originally Posted by bonjo
The new battery is labelled as "bad", desulfation, you can have the correct voltage but one or more of the internal plates faulty. Very rare on a new battery. But physical shock or mpoor manufacturing can cause it.
After my "old" battery was fully charged, according to the charger, I put the new battery on the charger overnight. In the morning, this is when it indicated "bad battery". According to Schaeffer, the charger manufacturer, it did talk about "desulfation".

Originally Posted by bonjo
What does walmart use to test the battery? The only way I know of to work this out is to do a CCA test. BTW the old style CCA testers can actually damage the battery, You need an electronic one (very exoensive!)
It looked like the type you'd see in a repair facility, had a heat-sink section or louvered section (for something that creates heat obviously), and a digital readout. One of the tests, it indicated CCA and by the time I looked at the screen, it was reading 700-something and eventually went up to 780+ and the guy insisted the battery is fine.

I even called Schaeffer tech support to ask why their unit says the battery is bad when a more professional unit says otherwise. He suggested charging it again and I presume, not leaving it on for 8+ hours. He said charge it and check it every 30 minutes or so. Once it switches to "maintain" mode, turn it off. I did that one day and repeated it a 2nd day. After this, all seemed well and it's installed at this point. I kept the "old" one for close to a week just in case. I think the indication of a bad battery was just a glitch or fluke, at least I hope so !
 
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