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
You are describing a battery that needs replacing
You can try unhooking the battery over night and see if it drops on its own, if it doesnt you might have something on the car draining it (mabye a interior light on). Can also take the battery out and alot od places will test it for you for free
Either the battery is failing or you have a parasitic draw.
So from experience, Kia’s will sometimes keep the visor mirror light on after you shut the engine off even if you put the visor up. You need to close the little door on the mirror, to shut off the light then put the visor back up. The little light on will draw on your battery overnight.
Not saying that’s what’s going on but just as an example of the odd little things that can lead to a power draw without you even thinking about it. Turning the car off doesn’t always mean that everything inside also turns off.
Try unplugging all of the usb stuff and make sure all the lights are set to off and see if you’re still getting a lower voltage.
12.48 isn’t particularly good fresh from driving. Two tests that would shed more light on the issue are what voltage is the alternator putting out while running. And does the battery drop like this when disconnected.
This is the correct answer
What’s the voltage during cranking ?
If it’s dropping below 10v during cranking you likely have a weak battery.
Voltage with engine running should be 13.6v+. If not alternator is weak.
If you’re able to stay above 10V during cranking but the charge is dropping overnight something is consuming it. Such as a charger or other customer installed consumers such as a remote start system. Audio system. If none of that is present then I’d see what OEM stuff is staying on.
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
Might be. Could also be a slow draw on vehicle.
Do you have the means to jump start your car if it doesn’t start itself?
All you really need is a set of jumper cables and the confidence to ask a neighbor or good samaritan for help jumping your car. OR a roadside assistance plan.
If you’re comfortable jump starting your car, then IMO just wait for the battery to actually die instead of replacing early. Batteries tend to last anywhere from 3 to 6 years.