It almost got up to freezing today so I popped the hood and started checking things. The car started right up like there hadn't been a problem. I cleaned some corrosion off the terminals and tested everything I could think of. I couldn't find any reason for the no start.Stopped by the parts store and had them check it with their more deluxe charging system tester. Alternator output was 14.1 volts. Their print out said the battery was good with proper reserve and cranking amps. Alternator was good. Diodes were good. Charging current failed. How that can happen with 14 volts is beyond me.

I'm going to stop by a different store tomorrow and see if they get the same result and it wasn't a faulty tester. Any ideas? I want to find why it didn't start as I won't have a car I can't rely on. Not while I'm still making payments.

 

More likely the results are from an inexperienced hourly wage employee The results you posted and your comments about the condition of the battery have me very suspicious of the testing results?

 

I've tracked the problem down. There were some suggestions that seemed odd to me but I looked anyway. They were way off the mark. Consumer Reports gave the '16 CX-5 high marks before I bought it but they said the electrical system was a bit iffy.

I tracked it down to the voltage regulator in my alternator is failing. 13.5 normally running but spiking to over 14. Once it hit 14.9. I can get a regulator and replace it, but with the fun of removing the unit, I suspect I'll replace the alternator.

In short, the alternator is about to pack it in.

 

Problem solved. I was relying on compooters and they were telling me it was working, yet not. I went back to my training from the 1960's and treated it like a 1930's or so piece of equipment. I got my volt/ohm meter, a transistorized, but NOT computerized charging tester and basically, I had a battery low on electrolyte. Took it to a battery shop and for $20, he popped the case open, topped two cells off and resealed it. He retested it and it passed with flying colors. It's life may be shortened with the extreme cold, but it's 100% now.

My family wonders why I don't always trust computers.

 

sure but serious who would go to the trouble of breaking the sealed top cover of any battery? WOW not only takes some labor, semi dangerous but only results in the end on temporarily prolonging the already shorten life of the battery. As for your testing I commend your efforts but there is a lot more procedure when testing electrolyte correctly! More then just a volt "meter". .
Good Luck with your solution but I may recommend to make sure you are currently paid up on your AAA membership and carry a set of quality jumper cables.

 

Evidently you have a well endowed trust fund that has matured. Myself on the other hand, $20 compared to $150-200 when you're on social security makes a difference. As for cracking the case, when you know what you are doing, it's not hard nor particularly dangerous. When I ran a shop, I made sure the customers got the full value out of investments. Not everybody has the money to waste without need.

 

Ok so you do realize how electrolyte works and especially what happens when 50% of a 12volt car battery is discharged. ? I said I commended your efforts it is just not really practical in the long run on a vehicle that has so many on board electronics. Maybe pre 1995 it would be sorta ok but nothing really into OBDII and CAN-bus systems. And before you get into your "voltmeter", I have all my old battery testing and basic electrical testing equipment "NONE DIGITAL" that dates back to the mid 70"s. Digital was for electricians that made bucks not for us just starting in the auto mechanical world.. As for cracking the top on a battery I don't think I know anyone that would do that ever except back in the day I wanted to see the inside of a battery and dissembled one. What a PIA!!

Oh and you BS comment about a trust fund really dude....... I have worked very hard over decades and even had to personally pay for my education!!!!!! Don't assume things about anyone especially on the internet!

 

I've been retired for 4 years and have an excellent 401K stash which I have not touched and don't plan to, it'll be for my kid.
I have had AAA for decades now and it is well worth the yearly cost, especially now that changing a tire would likely permanently lock up my back
My wife and I live comfortably only SS and can still put money in the bank, I paid cash for my CX-5, and I've never once made a 6-figure salary.
Ones finances depend not on what your income is but how you manage it.
The monthly SS COLA for 2023 will easily buy you a new battery.
Me, I would've put the $20 toward a new battery with a warranty not gambling it on an old battery "hoping" it will last.
The average life of a sealed car battery is 2-6 years, once you break that seal the battery can go anytime.
Please keep us informed as to how long your battery functions as needed.