Any advice about the following? The certified 2022 PP with 24K miles that I acquired in October 2024 is showing some intermittent electrical problems. It’s driven almost every day, and always to operating temperature. Nevertheless, although replaced at certification, the battery has failed to start the vehicle on a couple of occasions and had to be jumped. The resting voltage is 12.3V after which suggests ~70% charge (with engine idling it's 14V). I asked the dealer to check the battery last week when during routine service and was told it was OK. But that doesn’t seem right. BTW, Mazda doesn't warrant replacement batteries, even one that is only 4 months old.

Another weird one-time occurrence was the temperature gauge hitting the red zone—the engine was hardly warm. Needle returned to normal on restart.

 

I would definitely replace the battery before anything else. Easy DIY. I just swapped my 21's battery a couple of weeks ago even though it wasn't showing any issues. This is what I bought (https://www.weizeus.com/products/wei...i-dohc-152-cid)
They shipped right to the house for free. 3yr warranty and AGM. Great battery so far. 3yrs is what is said to be the life of an OEM battery.

 

autozone will test a battery for free...i picked up a battery tester a while back so i could do it at home https://a.co/d/adxn90t

 

Before doing any replacement of the battery charge to min.12.50 volts and have it load tested.
Your rested voltage should always be at least 12.50 min and if it is not you are reading the normal system draw on the battery or you have another none related battery electrical concern.
The time you purchased the battery or when you purchased the Mazda or any other platform vehicle has no indication when the battery was actually manufactured.
Not sure about you claim about no warranty on a 4 month new purchase of a battery? Never read that before unless it was a replacement and prorated? I guess???????
Assuming.... no DTC and you checked your ECU in at least 2 of the 3 main areas
Based on your first response you should see at least 1 if not more!!!!!

The charging rate @14.00 volts is not complete because your Mazda ECU controls the charging rate based on the battery and the load. Some of what you post seems you are still in OLD SCHOOL mode for charging system and battery information. No insult intended. I am use to that almost daily from DIY on the internet and coming into the service shop.

No matter what the electrical issue may be even as simple as a blown fuse it is smart to have your battery tested!

If all this is checked and it proves to be a bad battery and something else you have not yet found then what chickdr19 suggested is great recommendation for a better replacement. But I recommend NOT until you resolve the issues and find out facts about your battery charging system, and what will I am sure be something yet discovered.


I forgot to mention go to a Pep Boys or AutoZone, or Firestone for a free battery load testing. Because your specific information you posted not the dealer!!!!!

 

Also- this is a certified car. It would seem the dealer owes you some love to figure out what is going on if it isn't the battery. If it is something such as the alternator, that would likely be covered under the warranty.

 

First post info OP purchased October last year so , your thought not likely . About the only remaining item on the warranty remains would be emissions related?
Alternator would have likely expired for warranty coverage and nothing likely remaining would cover free Diagnostics troubleshooting.
But he should at least ask or read the Warranty info he has on his used vehicle purchase.

 

As pointed out you need to get the battery load tested to be certain.
I can tell you 3-5 years is the norm for high end battery meaning 3 years is most likely for the OEM.
If it is the battery it doesn't hurt to see if the place you purchased it at will replace it.
I got my shop to replace mine and with the battery of my choice free of charge, but I've been buying from them for the 25 years.