Is this with the engine running?
If the engine is off it’s a little low, depending on how much load there is (accessories & lights).
If this is with the engine running there’s a problem with the charging system.
It should be 13.5 to 14.5V.
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I assume the red numbers are temperature. We really need to see what voltage reading shows while the engine is running around 1,200RPM. The static voltage reading is lower than it should be. You should read close to 12.6 volts or more when the engine is off and the battery is fully charged.
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No this is with the engine off, i haven’t tried it with the engine on yet, the only accessories that was on was the lights because i had the car door open
when i used the meter i did leave the car door open which left the lights inside the car on.
You would be incorrect in stating that because the belt is tight it means the tensioner is good. Not so.
In a prior post what I said was that it’s possible for a new belt (and tensioner) to slip because the alternator pulley (or other pulleys) are worn.,
Want to know if the alternator is good with a backyard method? Turn the key to the RUN position (engine NOT running) and touch the alternator pulley with a screwdriver or other ferrous metal object. If you can feel the magnetic attraction in the pulley the alternator is good.
If the alternator is good and is NOT charging the battery then you need to consider a blown fusible link; which is a fused circuit between the alternator and battery positive terminal. All easily checked…
Some may disagree but I tend to kind of think I know what I’m talking about… 
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DriveTime,
That meter is helping already!! Unfortunately, bad news.That is a low reading on the voltmeter, assuming it is accurate, Is there any load on it, like a dome light with headlights or something else on? Cougar is right, what is the voltage when at a normal idle, during the day with no headlights? It should be in the 14-14.4 or so range. When the car is turned off, it should immediately be about 12.9 Volts with no lights or anything. Anything lower means something is wrong.12.2 is definitely in a problem range. If you know somebody with a more trustworthy (Fluke Brand preferably) or something of equal quality to verify your mini-meter.
Considering the history of battery’s you have given, I’d say your lucky it’s starting. Does the car sound like it is turning over fast? You keep feeding me the info, we will get this figured out.
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@hubert275_171399 The OP did state that when using the volt meter she had the car door open which had the interior light on.
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This vehicle is only driven 5 miles each week and it might spend more time with the doors open than on the road. This is why the battery should be recharged every few months.
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88 posts when it seems that a 30 to 45 minute drive each week would solve this .
Drivetime’s idea about taking a class for vehicle repair is not really that good. The cost of class , tools and diagnostic equipment might be more than buying a new vehicle . Which also would have battery problems if not driven enough.
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Thank you, i appreciate all your help with this, after circuitsmith said “depending on how much load there is (accessories & lights).” i remembered that i did have the door open and lights on when i use the meter so last night i went back out and rechecked it with the door closed and it read 12.5, tomorrow we are taking the car out so i will test it with the engine on and post what the number are plus i do think there is a more accurate meter that plugs in the lighter on amazon it a Jebsens and i will order that one. I wish i could get a meter you put right on the battery but the hood latch is so loose I’m afraid to open it until we get the oil changed because it might break the next time i try. When we started it yesterday there did seem to be a little drag in the starter but i could be wrong, i will listen more carefully tomorrow. I was thinking and i know i’m not a expert but if keeping the lights on when i used the meter took 3 volt off the reading and made it 12.2 and checking again with the lights off add back 3 at 12.5 that means i’m still missing 4 volts somewhere if it’s supposed to be 12.9 so maybe something else is on in the car and i don’t see it, maybe the light in the glove box or something like that, of course i’m no expert just thinking…
i totally agree, the class and tools i couldn’t afford right now and even if i could it would be better to buy a new car with the money. My plan is to become a artist or win the lotto and buy my mom a new car. (God willing)
Actually, a full, healthy battery will settle out to 12.6-12.7V after sitting for some hours, with no load.
Also, when you have lights or other accessories on there will be a small drop in the wiring, so while the meter read 12.2V at the lighter socket it was a bit more at the battery terminals.
But that’s splitting hairs. Plus, you haven’t verified the accuracy of your meter.
A basic digital meter can be had for ~$20, and you can use that to compare with your plug in meter.
Example:
https://www.amazon.com/AstroAI-Multimeter-Ohmmeter-Voltmeter-Non-Contact/dp/B0842HTN8C
BTW, I keep this meter plugged in my lighter socket, and I’ve verified it’s accurate +/- 0.1V:
https://www.amazon.com/gp/product/B01M9IKYVH
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Just as a quick reference, I took my car out a little while ago and plugged in the voltmeter. It read 13.7 while driving. With the car off, it read 12.7. So I know the battery is good and the 13.7 says the alternator is charging the battery. These readings are pretty much what they should be.
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You have calibrated equipment at work to make this an easy check. How can people without access to calibrated equipment test their VOM?
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Go to a shop that has a decent meter or two with a box of donuts and ask them to do a comparison.
In the OPs case a new $20 DVM can be a trusted standard, with 10X the resolution of the lighter socket meter.
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During this Virus problem I doubt if any shop wants strangers showing up just to get a free calibration of anything. Even with donuts.
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Where are we likely to find those shops? I can take stuff to work too, but most of us don’t have that opportunity.
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Again, a new $20 DVM can be trusted to read a 12V battery within 0.1V.
The 6+ digit meters I have at work would be overkill.
Why make a mountain out of a mole hill?
Or is this just a battle to have the last word?
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@drivetime Hi Drivetime. As a woman who has been getting good advice here about my cars for many years, I’m jumping in to offer some advice.
Time to refocus on the essential problem of your battery repeatedly going dead and the simple remedy you have been advised to take.
-
Drive the car farther to keep the battery charged
This is the essential action needed as advised by everyone responding!
Failing to drive the car far enough to charge the battery more than it gets depleted by starting the car will continue to kill the battery.
You need to budget time and budget money for gas for driving long enough and far enough each time to adequately charge the battery. So if going out only once a week for groceries and other essentials, take time to drive awhile before stopping at the store. It’s that simple. -
Use your volt meter as instructed which is to take a fairly long drive to check if the alternator is properly charging the battery.
The only way to know if the alternator is doing its job and if the battery is fully charging and maintaining charge is to drive far enough to test these critical factors. Again, the universal advice you have gotten is to drive the car far enough.
Focus on this essential basic first!!! Follow the universal advice given to drive the car far enough to properly charge up the battery.
Report the volt meter readings from taking a good, long drive. Then the knowledgable, experienced experts can continue to help you. But first you absolutely need to follow their direction for that first step which is to drive the car farther distance.
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I know we have a few engineers here and I don’t want to spoil the party but getting a calibration check on a $10-20 plug in volt meter is . . . OK kinda extreme. In other words who cares if it’s off a little. As Taryl would say, it’s not the space shuttle. The important part with a $10 meter is to do a basic base line reading. Then in future readings you will be able to see the trend. Mine read 13.7 v. So it could be off .5? Doesn’t matter.
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