So, I have a 2019 6.7L F250.

Went to start it this afternoon after it sitting for two days and it wouldn't turn over, but I would get a click.
Clipped my handy dandy rechargeable jump starter to the driver side battery and nothing. Tried that a couple of times.
Last blast chance I clipped it to the passenger side battery and it started right up. It's out there idling now.
I had the batteries replaced under warranty about 2 months ago and have either just passed or just about to pass the 36 months ago warranty I have in them from 3 years ago when I replaced them.
The passenger side battery terminals look fine; however, the driver side positive terminal looks like I haven't changed the battery since 2019 when I got the truck. Lots of acid, I guess, has seeped out and has gummed it up quite a bit. Surprising because, as I said, the batteries were replaced 2 months ago.
So, my question to the automotive board: anyone have any idea what the f*** could be going on here?
Thanks in advance for any help you can give!

Edit to add pics of passenger and driver side terminal connections.

Just checked voltage of both batteries after disconnecting them. Each was at about 12.74 V -12.78 V.
Guess I will have to jump it tomorrow morning and take it back to AutoZone.

Edit: both batteries read 14.62 when truck running.

Sounds like the batteries are currently charged. The 14.6 volts was coming from the alternator. No idea what may be causing your batteries to drain. Possibly a bad cell in one of the batteries

Clean the posts and the clamps and re-connect. make sure the negative ground cable are tight where they connect to the frame.

Sounds like a connection problem and not a battery problem.

ghollow said:

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Clean the posts and the clamps and re-connect. make sure the negative ground cable are tight where they connect to the frame.

Sounds like a connection problem and not a battery problem.

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That's exactly what it was. When I went to take it to AutoZone this morning, I decided to try starting before I boosted. It started right up like there was no problem. I guess removing the cables from the posts and putting them back on yesterday re-established a good connection to the driver side battery.
Took it to AZ anyway and both batteries checked out in good condition.

Might disconnect and load test both batteries.

Have found that some small percentage of batteries can come off the shelf with a bad cell and go downhill from there. Good voltage only half the problem and you can chase your tail trying to diagnose without verifying that you have a known good battery by way of load test.