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2024 Tesla Model Y — eV has plenty of main battery but shows a 12V warning

RustBeltDad777Community StarterMay 10, 20262024 Tesla Model Y Long RangeBrooklyn
2024 Tesla Model Y Long Range, about 44,000 miles. Traction battery is charged, but a low-voltage warning appeared after the car sat overnight. I know the small battery can still immobilize an EV. What information would you capture before service?
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8 replies

TrackCollectorCommunity StarterCommunity StarterMay 10, 2026permalink
Low-voltage gremlins will strand you even with a full pack. Try a second charger before blaming the 2024 Tesla Model Y — site sharing and pack temp change the curve a lot. That's where I'd start. This is from a 2024 Tesla Model Y in Brooklyn with 44,000 miles. Was this after sitting overnight? Parking it somewhere I can hear it better next time.
RoadHaulerCommunity StarterCommunity StarterMay 10, 2026permalink
I'd treat 12V warnings as a no-ignore. On the 2024 Tesla Model Y, I'd get the 12V/DC-DC side checked even if the traction pack looks fine. That's where I'd start. On “ev has plenty of main battery but,” that was the fork that mattered for me. Had a similar mess a couple years ago and that's what finally sorted it. No warning lights, which is why I'm documenting it.
UsedCarGarage59Community StarterCommunity StarterMay 11, 2026permalink
I'd push back a little: Match starting SOC and battery temp if you're comparing 2024 Tesla Model Y charge sessions. Then you'll know the next fork. That's the whole play. Make the next action something you can finish this week. This is me being the wet blanket on purpose.
UsedCarGarage59Community StarterCommunity StarterMay 11, 2026permalink
Don't clear the alert just to make the screen pretty. Leave the alerts on the 2024 Tesla Model Y so service can see what you saw. Then you'll know the next fork. Do that first. I'd rather be boring and correct. If the story changes I'll post the new data.
RustBeltDad777Community StarterCommunity StarterMay 12, 2026permalink
It did ev has plenty of main battery but twice this week, both times after sitting. No change in mileage feel. Might be overthinking it, but I'd rather overthink than overspend.
NoMarkupFanCommunity StarterCommunity StarterMay 11, 2026permalink
Charge curves lie if you don't match starting SOC and temp. Match starting SOC and battery temp if you're comparing 2024 Tesla Model Y charge sessions. Then you'll know the next fork. I'd want that in writing, not as a promise. Make the next action something you can finish this week. This is me being the wet blanket on purpose.
BatteryLearner102Community StarterCommunity StarterMay 12, 2026permalink
Yes, with one caveat: On the 2024 Tesla Model Y, I'd get the 12V/DC-DC side checked even if the traction pack looks fine. I'd do that before spending real money. On “ev has plenty of main battery but,” that was the fork that mattered for me. If they can't show the line item, I assume it's hiding. I'll poke at it this weekend.
RustBeltDad777Community StarterCommunity StarterMay 11, 2026permalink
Tried a second charger / second scan and the story on the 2024 Tesla Model Y didn't change. Next check is the cheap one I can do in a driveway.
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