HV Battery Health & RangeQuestionCommunity Starter

2024 Kia EV9 GT-Line — need advice: How are you estimating real battery degradation?

FlatSixDetailer66Community StarterOct 6, 20252024 Kia EV9 GT-LinePennsylvania
Dash range changes with temperature and driving, so I'm looking for a better way to judge battery health. What data do you trust—usable kWh, charging energy, service-mode values, repeated range tests? I'm in Pennsylvania. Any data points from owners would help. What am I missing?
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11 replies

PistonTech5Community StarterCommunity StarterOct 6, 2025permalink
Low-voltage gremlins will strand you even with a full pack. Try a second charger before blaming the 2024 Kia EV9 — site sharing and pack temp change the curve a lot. That's where I'd start. This is from a 2024 Kia EV9 in Pennsylvania. I'd want that in writing, not as a promise. This is me being the wet blanket on purpose.
QuattroGeek8Community StarterCommunity StarterOct 6, 2025permalink
I'd treat 12V warnings as a no-ignore. On the 2024 Kia EV9, I'd get the 12V/DC-DC side checked even if the traction pack looks fine. That's where I'd start. On “line — need advice: how are you,” that was the fork that mattered for me. Learned this the expensive way on a previous car. This is the version I'd tell a friend.
QuattroMomCommunity StarterCommunity StarterOct 6, 2025permalink
Don't clear the alert just to make the screen pretty. Leave the alerts on the 2024 Kia EV9 so service can see what you saw. I'd do that before spending real money. Happy to compare notes if your setup is different. If this is nothing, great. I want that in data.
TurboRiderCommunity StarterCommunity StarterOct 7, 2025permalink
Low-voltage gremlins will strand you even with a full pack. Try a second charger before blaming the 2024 Kia EV9 — site sharing and pack temp change the curve a lot. I'd do that before spending real money. This is from a 2024 Kia EV9 in Pennsylvania. Post the numbers (or the code) and people can get more specific. Only after sitting overnight so far.
RotorFanCommunity StarterCommunity StarterOct 8, 2025permalink
Yes, with one caveat: On the 2024 Kia EV9, I'd get the 12V/DC-DC side checked even if the traction pack looks fine. Then you'll know the next fork. On “line — need advice: how are you,” that was the fork that mattered for me. Had a similar mess a couple years ago and that's what finally sorted it. This is the filter I use when the thread starts repeating itself. No warning lights, which is why I'm documenting it.
EuroNomad49Community StarterCommunity StarterOct 7, 2025permalink
Charge curves lie if you don't match starting SOC and temp. Match starting SOC and battery temp if you're comparing 2024 Kia EV9 charge sessions. Then you'll know the next fork. Write the result down so the next test isn't a repeat of the last one. I'm keeping receipts and dates in one folder.
QuattroMomCommunity StarterCommunity StarterOct 7, 2025permalink
I'd treat 12V warnings as a no-ignore. On the 2024 Kia EV9, I'd get the 12V/DC-DC side checked even if the traction pack looks fine. Then you'll know the next fork. On “line — need advice: how are you,” that was the fork that mattered for me. This is from a 2024 Kia EV9 in Pennsylvania. Happy to compare notes if your setup is different. If your situation is the opposite, ignore me. Video is ugly but it shows the hesitation.
PistonTech5Community StarterCommunity StarterOct 8, 2025permalink
Fair point. Counterpoint: Match starting SOC and battery temp if you're comparing 2024 Kia EV9 charge sessions. Then you'll know the next fork. This is from a 2024 Kia EV9 in Pennsylvania. Verbal 'we'll take care of it' is not a plan. I'd rather look cautious in this thread than stuck later.
RustBuyerCommunity StarterCommunity StarterOct 7, 2025permalink
Low-voltage gremlins will strand you even with a full pack. Try a second charger before blaming the 2024 Kia EV9 — site sharing and pack temp change the curve a lot. I'd do that before spending real money. Do that first. Video is ugly but it shows the hesitation.
JDMCamperCommunity StarterCommunity StarterOct 7, 2025permalink
Don't clear the alert just to make the screen pretty. Leave the alerts on the 2024 Kia EV9 so service can see what you saw. Then you'll know the next fork. Happy to compare notes if your setup is different. Not trying to scare you — just skip the expensive first guess. I'd rather look cautious in this thread than stuck later.
QuattroGeek8Community StarterCommunity StarterOct 7, 2025permalink
Charge curves lie if you don't match starting SOC and temp. Match starting SOC and battery temp if you're comparing 2024 Kia EV9 charge sessions. That's where I'd start. A shop burned me once by skipping that step. Next check is the cheap one I can do in a driveway.
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