Is your battery really bad?

[partsman48210]

I'm posting this as just something to think about off of first hand dealings with batteries determined to be defective by local parts stores.

Don't believe everything your local parts guy tells you, and this is why:

I used to work for a U-pull salvage yard here in the Detroit area. Part of my job was testing all the batteries that came in with cars and to bring the good ones up to the front for resale. I would bring the batteries up every morning after they charged overnight and were tested in the morning. I would take back all the battery cores that were brought in by customers and my favorite thing to see on core batteries was that bright yellow sticker on the side that said "bad" and a few other things. Some of you have seen this sticker. It's from autozone or oreillys and brings a frown to most peoples faces knowing they will now have to fork out a whole bunch of $$$$ for a new battery.

Hold your horses, not so fast. The reason I loved seeing this sticker is because we sold more used batteries than we could get and most of these so called "tested" "bad" batteries brought in as cores were not bad at all. I would throw a good charge on them and load test them and 9 out of 10 really were still good batteries. I would then let them sit overnight off the charger and test them again in the morning before putting them back out for sale.

There are some good knowledgable people at the parts stores but there are just as many guys working there that think they know more than they actually do and end up costing people more than they should because of their arrogance and refusal to admit they dont know how to do something correctly..

Use this knowledge however you will. I'm not the all knowing and will never claim to be but if this saves one person from throwing out a bad battery thats actually good then I have succeeded.

 

[SoHK_alumni]

Very true, the rapid charge most parts houses put on a battery is only surface deep and a far cry from a full deep charge that brings the specific gravity of the battery acid back up to par.

Its only after a deep charge that won't correct the acids can you say the battery is probably NFG.

Might be old school but the old hydrometers are hard to beat when testjng batteries.

 

[wifes2011xlt]

I hope you did a full analysis and not just a load test on those used batteries you sold. Plenty of batteries that test fine on load test but still won't start a car because of bad plates. Load tests don't tell you much about the cranking amps that the plates conduct.

Have the auto parts store clerk test it front of you and just watch them hook the leads up to the posts and see what the gauge spits out. It's not rocket science. The gauges might even be color coded.

 

[partsman48210]

I hope you did a full analysis and not just a load test on those used batteries you sold. Plenty of batteries that test fine on load test but still won't start a car because of bad plates. Load tests don't tell you much about the cranking amps that the plates conduct.

Have the auto parts store clerk test it front of you and just watch them hook the leads up to the posts and see what the gauge spits out. It's not rocket science. The gauges might even be color coded.

No it's not rocket science. I trust my 20+ years of knowledge and experience as a mechanic over the guy who has been working at AutoZone for 3 weeks or has never turned a wrench in his life

But that's not the point.. The point is there are a lot of people that visit forums for answers that are first timers or novice mechanics. They trust in the words printed on these pages to help solve problems. They also trust that the local parts guy knows what he is talking about and won't steer him wrong.

I'm sorry if I did not give explicit details on how to "analyze" a battery and that my information was insufficient for you

 

[wifes2011xlt]

No it's not rocket science. I trust my 20+ years of knowledge and experience as a mechanic over the guy who has been working at AutoZone for 3 weeks or has never turned a wrench in his life

But that's not the point.. The point is there are a lot of people that visit forums for answers that are first timers or novice mechanics. They trust in the words printed on these pages to help solve problems. They also trust that the local parts guy knows what he is talking about and won't steer him wrong.

I'm sorry if I did not give explicit details on how to "analyze" a battery and that my information was insufficient for you

I'm sorry that I actually had to try to get more explicit details from you. Your post read like all you did was charge the battery, load test it, let it sit overnight and if it load tested fine again, then you would flip the battery on a secondary market. I was actually just trying to take your advice. You know, don't trust the local parts store guy???

 

[partsman48210]

I'm sorry that I actually had to try to get more explicit details from you. Your post read like all you did was charge the battery, load test it, let it sit overnight and if it load tested fine again, then you would flip the battery on a secondary market. I was actually just trying to take your advice. You know, don't trust the local parts store guy???

I understand what you're saying and I would never intentionally sell someone a bad product just to make a buck. If it was up to me I would test the cores before a customer purchased another battery. By the time I got the batteries that customer was long gone.

As to your point about testing, as long as it is tested correctly it will show a dead cell if it has one.

Here's a link to proper testing because I didn't plan on getting into all of it. http://autorepair.about.com/library/weekly/aa101604c.htm

 

[wifes2011xlt]

As to your point about testing, as long as it is tested correctly it will show a dead cell if it has one.

Well, yes, but my suggestion to test the plates is another analysis to conduct if the battery is tested properly and still shows cells are good. Cells can test fine but plates can still be bad. A conductance test will give you a good idea on how healthy the plates are that are needed for starting.

Here is a link that explains how to measure cranking amps (need for starting) with a battery conductance tester….around the 7:00 mark.

http://youtu.be/Oi8sUE9XCgA

 

[partsman48210]

And all of this goes well beyond what AutoZone will do for someone before they just try to sell you a battery. And then said person comes to these forums because their problem is still not fixed. I've seen it in numerous posts.

 

[wifes2011xlt]

It's been my experience that if you walk into Autozone knowing what tests you want run, you'll get a much better diagnostic. I've seen guys walk up to the counter asking if they can get their battery tested and the clerk grabs a voltmeter. :scratch:

If a clerk tried that with me, I would say I already tested with a voltmeter and want bench testing under load and CA/CCA measured.