Battery is a diehard bought in June 2023 (original owner left the receipt with the battery, 2yr warranty). Leaving the car in the garage for 2 days and I jump in to go to work and battery was dead, jumped and went to work no issue later. Waited till the next weekend and battery went from 12.39 vdc to 11.51 just after a day and a half. When running I am getting 14.25 vdc so alternator is working.

Took it in to Advance Auto last Sunday and had it load tested (19 year old girl), they claim it is good (told me battery is 590 cca and after tested it had 418cca (how is that good?)). I drive 45 miles to work one way (work 2nd shift), got out of work Tuesday, 30 degrees out and had to jump it to get it going.

I'm pretty confident its on its way out. Now that its getting colder at night its becoming an issue. Terminals are clean and tight. Tomorrow I want to take it back to a different Advance auto (one where battery was purchased from) and get i tested again, would it be better to pull it out and take it in to have it tested or drive it in again? What in the hell could be causing a short battery life? I unplug my phone charger, nothing is left on, just don't get it. If it tests good again I am just going to go somewhere else and bite the bullet and buy a new battery.

 

12.39 is a dead battery. Should be better than 12.6.

 

Any chance the car sat undriven last Winter? A discharged battery sitting in the cold will “sulfate up” even if new. Loosing voltage that quickly suggests that possibility.

A good battery should hold 12.6 V or so. I would get it to at least that, then remove the + cable and see if it still self-discharges. If not, you might have a parasitic drain. Any aftermarket doodads or a radio installed?

Any chance the battery in it isn’t the one replaced last year?

 

I don't know, I bought it in August. I don't get how it passed a load test?

 

I agree, how did it pass a load test? Only thing I can figure is it charged while I drove it there, that's why I am wondering if I should pull the battery to take it in and have it tested?

 

A load test should be done with battery connected in the car. I had a 6 month old battery go bad it had a dead cell. It passed my fall load test , after driving down to Florida it was just dead! ☠️

 

Took it to a different Advance Auto, load test failed, they replaced it free of charge. I really believe the teenager who did the initial load test someone did it wrong, atleast got it done.

 

Pretty sure my battery is on its way out too with my snap on scan tool plugged in without the car running it’s 11.7 with it running I’m mid 13s

 

Sounds like it.

 

Yes that’s a good reason for a new battery and vent tube!