I don’t know much about this, but we a 2020 2020 Kia Sedona with 36,000 miles, original battery. It had trouble starting the other day but I believed that was from an open door and light being left on. It has been driven about 2 hours since then. The 12.48v reading was right after I drove and turned car off. The morning reading was a cold 30F morning if that matters. I don’t know too much about cars so wondered it was worth replacing. Thank you
Wasn’t able to check it during cranking as I was by myself, but while it was running it was 14.36v. I didn’t disconnect it, but seeing as I haven’t modified or adding anything to car since we bought it, I think I can rule that out. Sounds like it probably just the battery which I’m fine with. Thanks for the advice on the troubleshooting