See image. Car was level 1 charging overnight using a charger I borrowed from someone else. It was at 30% when I went to bed, so there’s no way it got to 79% in a few hours.
I was hoping it was an app issue, but this is what is showing up in the car as well. Is there a way to reset the battery reading?
Based on advice from other threads, I pulled the hv fuse and unplugged the negative terminal on the 12v for a few minutes. Now the battery reading is back to 33%, which seems right given the cold weather. Thanks for the support everyone. I’m still puzzled by what caused this but I think I’ll avoid using this charger in the future.
@Nyle
It’s concerning that you had to take those steps. It might be worth a trip to the dealership, although they can be hit or miss with their diagnostics.
Ezri said:
@Nyle
It’s concerning that you had to take those steps. It might be worth a trip to the dealership, although they can be hit or miss with their diagnostics.
Thanks for the suggestion. I think it was a software glitch and my intervention might not have been necessary. The car would likely drive according to the displayed range, but I’m not sure it would accurately warn me as the real SOC dropped. I just feel better knowing the display now matches reality.
@Nyle
I agree. It’s likely that a full charge and re-balancing the cells on a Level 2 charger would correct the issue. Even an 80% charge might be enough for the BMS to recalibrate.
@Nyle
I would’ve tried setting the AC charging limit to 80% to see if it stops charging when it reaches that level, which could indicate whether the car thinks it’s fully charged.
Kemper said:
@Nyle
I would’ve tried setting the AC charging limit to 80% to see if it stops charging when it reaches that level, which could indicate whether the car thinks it’s fully charged.
I did set the charge limit to 80%, and when I woke up it showed the charge was complete at 80%. For some reason, it dropped to 79% before I took the photo.
The core issue isn’t just about range—it’s how your vehicle managed to charge 50% overnight on a Level 1 charger. This could indicate a problem, potentially with the battery management system or a software error. I’d keep an eye on this and possibly seek further diagnostics.
@Aubrey
Agreed. A charge increase of 49% on Level 1 charging overnight is improbable. It sounds more like a calculation or software error.
Parker said:
@Aubrey
Agreed. A charge increase of 49% on Level 1 charging overnight is improbable. It sounds more like a calculation or software error.
If you’re driving in sport mode, in cold weather, with the heat on high, and a heavy foot—1.0 mi/kWh and no regenerative braking could make some sense. Just theorizing how those numbers could align.
@Zan
What are you suggesting exactly?
Parker said:
@Zan
What are you suggesting exactly?
I’m just offering scenarios where such discrepancies could make sense, albeit unlikely.
BMS systems can be quirky. It’s advisable to fully charge the vehicle occasionally and drive aggressively during that cycle to help the BMS recalibrate. Most software, including BMS, can have moments where they read data incorrectly. It’s not uncommon across various car brands.
This might be indicative of a faulty battery cell. I’d recommend taking it to the dealer for a check-up, especially since a similar issue occurred on a Level 2 charger.
Oli said:
This might be indicative of a faulty battery cell. I’d recommend taking it to the dealer for a check-up, especially since a similar issue occurred on a Level 2 charger.
You might be right. After testing with a Level 2 charger and observing the same issue, I’ve decided to visit the dealer first thing Monday.
Ignore the app for a moment and check the percentage directly in the car. Sometimes app backends glitch, especially post-update. If there’s a discrepancy, report it through the app’s feedback feature, but always trust the car’s own display first.
Just drive the car normally and charge it up to 100% when you can. Often, these issues resolve themselves once the battery fully cycles.
What app are you using? It looks different from mine.
Keller said:
What app are you using? It looks different from mine.
That’s the myHyundai app for the US market. Hyundai uses different apps in different regions.
Keller said:
What app are you using? It looks different from mine.
That’s the myHyundai app for the US market. Hyundai uses different apps in different regions.
That’s interesting. I wouldn’t have expected them to develop different apps for different regions.
