2016 Mazda CX-5 new battery needs jump

Bought a 2016 CX-5 Touring AWD in December 2020.
The battery has a sticker on it saying it was installed new SEPT 2020.
Today, June 2021, I drove to work just fine and when I came out the battery was dead. Nothing was left on. No lights etc.
I had to get a jump and drove home. Later I tried to start it again and it wouldn’t. All the connections were tight and clean.
I took the battery out, noticed the sticker (SEPT 2020), and took it to Auto Zone to be tested. It was at 10v. So something has obviously drained this new battery. They charged it up to 100% and I put it back in. The car started just fine.
But now it’s super stressful to not know whether my car is gonna start or not every time I go to start it.
The battery light was never on indicating a problem. What is draining it?
The starter sounds fine. The alternator belt doesn’t appear to be loose or have a bad bearing. ??? I’m puzzled 🤔

Thanks
 
...The battery light was never on indicating a problem. What is draining it? ....
First off you need to have the battery retested after it's fully charged, because even relatively new ones occasionally go bad. Next, assuming that it tests ok, the battery light not on doesn't automatically mean it's charging properly. You need to monitor the battery with a multimeter in order to determine if it's charging ok after being driven. At that point you'll have found out part of the story, and will know out how to continue diagnosing.
 
Do you have a multimeter/voltmeter? Check the battery voltage before starting. It should be in the 12 to 13 vdc range. Start the CX and measure the voltage again. It should be at or above 14vdc. If it's not then the charging system is suspect. If it's above 14vdc then the problem is most likely a bad battery. That battery needs to be fully charged and load tested.
 
Bought a 2016 CX-5 Touring AWD in December 2020.
The battery has a sticker on it saying it was installed new SEPT 2020.
Today, June 2021, I drove to work just fine and when I came out the battery was dead. Nothing was left on. No lights etc.
I had to get a jump and drove home. Later I tried to start it again and it wouldn’t. All the connections were tight and clean.
I took the battery out, noticed the sticker (SEPT 2020), and took it to Auto Zone to be tested. It was at 10v. So something has obviously drained this new battery. They charged it up to 100% and I put it back in. The car started just fine.
But now it’s super stressful to not know whether my car is gonna start or not every time I go to start it.
The battery light was never on indicating a problem. What is draining it?
The starter sounds fine. The alternator belt doesn’t appear to be loose or have a bad bearing. ??? I’m puzzled 🤔

Thanks
How many miles been driven on your 2016 CX-5 Touring AWD since you bought it? And what is the brand of the battery?

Drive your CX-5 back to the AutoZone or any other auto parts store and ask them to check out the charging system and alternator. Although the “battery” warning light was never on but that light is only meant if your charging system is having issues, not for the battery itself. If the alternator checked out fine, I’d go to the store which sold the battery and ask for free replacement. Most batteries now carry at least one-year replacement warranty. If the store refuses to replace the battery after they checked the battery, most likely the battery is fine. You can either get another battery with better warranty (such as Costco which is cheap and no questions asked if you ask for battery replacement, although the price has gone up from $79.99 -> $89.99 lately), or carry a jump cable or even better a small lithium jump start battery with the car all the time, and just wait and see.

IMO if the battery was drained dead at your first incident by something you forgot to turn off, the battery should be charged enough on your way home to re-start the engine the next day. All the interior lights or headlights are controlled to be turned off in a specific time frame (30 minutes?). And a car suddenly developed an electricity drain to make a good battery dead usually is unlikely. You problem could still be the battery, or the alternator. Start with the easy one, try to get the battery replaced first under warranty.

A friend of mine just had his less than a year old EverStart battery replaced at WalMart. Yes even a fairly new battery still can go bad.
 
I’ve driven it 5,000 miles since I bought it in December. The new batter was in there when I bought the car.
I do have a multimeter and can check that just to rule some things out.
The charge has held on the battery for a few days now.

I’ve read some weird things about parking sensors that don’t know the car is in park so the electric timer never goes off, and in general some other weird battery things with these years. Of course it’s an infinite rabbit hole to go down when you start googling electrical problems. I honestly hope it was just a bad battery. But it seems like it would’ve went dead faster than 9 months if it was.
I’ll probably end up taking it to CarMax and get a loaner while they sort it out. They’re good about stuff, but notorious for taking FOREVER and giving the car back about 3 times before it’s actually fixed.
 
You can test it at home with a volt meter. Charge it fully, to 14,7 volts with a good charger with 10 amps or more output (overnight at least), Lett it rest without load for 6+ hours. If it's good, it will show 12.7v. if it is 12.2, 50% charge, it should be replaced. between those voltages, it is weak and will die soon.

Check your charging voltage right after a start, It should be 14.2v, maybe as high as 14.6. Anything else needs attention.
 
Don’t waste your time with a multimeter. Take the CX to a large auto parts store and have it electronically load tested. No multimeter can do that. Make sure you get the printout. If the battery tests out okay, then the problem is most likely in the charging system. A small drain is possible too.
 
You can test it at home with a volt meter. Charge it fully, to 14,7 volts with a good charger with 10 amps or more output (overnight at least), Lett it rest without load for 6+ hours. If it's good, it will show 12.7v. if it is 12.2, 50% charge, it should be replaced. between those voltages, it is weak and will die soon.

Check your charging voltage right after a start, It should be 14.2v, maybe as high as 14.6. Anything else needs attention.
I put a digital voltmeter in my 2016 and I never observe the running voltage to be over 13.8v. I think it would be better for the battery if the charging voltage was 14+.

As for the battery, I can't recall having a bad battery that went dead (although 10v isn't completely dead, it's the cutoff voltage for the battery saver circuit) and then later held a charge. A possible cause of short battery life could be extreme heat, causing the plates to warp and shorting the battery. I don't think a battery would recover from warped plates.

I don't find it surprising that modern cars could have parasitic drains, after all you need the car to respond to the remote to open the doors, etc.

If I were you, and the battery seems ok after a thorough charge, I would just monitor the battery voltage, put it on a battery maintainer once or twice a month, and buy a jump starter for peace of mind.
It could take CARMAX forever to figure out an intermittent and minor current drain.
 
I’ve driven it 5,000 miles since I bought it in December. The new batter was in there when I bought the car.
I do have a multimeter and can check that just to rule some things out.
The charge has held on the battery for a few days now.

I’ve read some weird things about parking sensors that don’t know the car is in park so the electric timer never goes off, and in general some other weird battery things with these years. Of course it’s an infinite rabbit hole to go down when you start googling electrical problems. I honestly hope it was just a bad battery. But it seems like it would’ve went dead faster than 9 months if it was.
I’ll probably end up taking it to CarMax and get a loaner while they sort it out. They’re good about stuff, but notorious for taking FOREVER and giving the car back about 3 times before it’s actually fixed.

Your CX doesn't have any parking sensors.
 
Don’t waste your time with a multimeter. Take the CX to a large auto parts store and have it electronically load tested. No multimeter can do that. Make sure you get the printout. If the battery tests out okay, then the problem is most likely in the charging system. A small drain is possible too.
Using a multimeter is not a waste of time. The info you can get from a meter can be diagnostic if you know what you're doing.

I never said that a meter can load test a battery.

Did you read the last sentence of my post above?

"That battery needs to be fully charged and load tested."
 
Using a multimeter is not a waste of time. The info you can get from a meter can be diagnostic if you know what you're doing.

I never said that a meter can load test a battery.

Did you read the last sentence of my post above?

"That battery needs to be fully charged and load tested."
“If you know what you’re doing”. Right. For the rest of us, a load test gives all the information required to disgnose the battery, and of course it’s free and reduces the stress the OP has.

Oh, BTW I wasn’t replying to your post, so……
 
So a couple of days ago the battery had been fully charged at Autozone. It lasted a few days before struggling to start again.
I let it sit over night, went out in the morning and BEFORE STARTING got a voltage reading of 10.56. And WHILE RUNNING got a reading of 13.1
Does that tell me anything ?
 
So a couple of days ago the battery had been fully charged at Autozone. It lasted a few days before struggling to start again.
I let it sit over night, went out in the morning and BEFORE STARTING got a voltage reading of 10.56. And WHILE RUNNING got a reading of 13.1
Does that tell me anything ?
This means you should drive your CX-5 to AutoZone and get charging system checked.
 
So a couple of days ago the battery had been fully charged at Autozone. It lasted a few days before struggling to start again.
I let it sit over night, went out in the morning and BEFORE STARTING got a voltage reading of 10.56. And WHILE RUNNING got a reading of 13.1
Does that tell me anything ?
It tells you to load test the battery……
 
So a couple of days ago the battery had been fully charged at Autozone. It lasted a few days before struggling to start again.
I let it sit over night, went out in the morning and BEFORE STARTING got a voltage reading of 10.56. And WHILE RUNNING got a reading of 13.1
Does that tell me anything ?

It means the battery is probably toast. Discharging a Pb-SO4 battery below 50% State Of Charge shortens its life irreparably. I would guess one cell is shorted for some reason. That might also mean it is pulling so much current trying to charge that you alternator cannot drive it above 13.1V, or that you also have a bad alternator. More data, Mr. Spock!
 
It does sound like a bad cell. Each cell should be 2.1v.

Six cells gives you 12.6v.
Five gives you 10.5v.

Has it been hot where you are?
 
Yeah, that 10.56 is no bueno, probably holding a charge. - may be time for a $89.00 Costco Battery - YMMV
 
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Heat definitely kills batteries. How hot was it that afternoon?

I don't know where you are regarding the warranty on the battery. If you can find the receipt it should help.
 
Heat definitely kills batteries. How hot was it that afternoon?

I don't know where you are regarding the warranty on the battery. If you can find the receipt it should help.
Remember OP had brought his once dead battery to Autozone and passed the test. And the battery was at normal voltage for a couple of days without issue and now dropped to 10.56 V. IMO the charging system needs to get checked too as it also can be the culprit.
 
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