I have owned the car since August 2024, and this happened to me twice, most recently a week or so ago. The most recent time it charged to 96% when I had it set to 80%. I have not figured out why. Maybe the system just burps sometimes.

 

I’ve had mine since June of 2024 and it has never happened to me.
You could make sure your away charge setting is not set to 100% and make sure it has not lost your home location is all I can think would cause this. Unless maybe the GPS could not locate you and the car was thinking you were not at home. Mine sits outside all the time so it’s less likely that could happen where it might happen in a garage.

 

This morning, while plugged in overnight, the car charged to 100% charge state. I did not consciously set the requested charge state to 100%, as I always keep it at 80%. That's the first time in 4 months that I observed that. Both the delayed % and 'charge now' % are normally at 80%.

A pal with Blazer EV has had this happen a couple times too, maybe once a month for him. (and in fact, he reports that his Blazer did this last night also)

This was not a case where I requested 80% and it went to 83%, i.e., some small variation from the requested number. The car clearly wanted to go to 100%.

Reasons I could think of that could cause this:

A) I somehow set it to 100%. I really don't think I did that. However, upon looking after it reached 100%, I see it is set to 100%. Unless there is a record of the requested states, I can't prove/disprove this.

B) I used a public charger yesterday, and went to near to 80% using that charger. That Shell L2 charger was much stronger (11.5 kw) than my weak 20 Amp L2 (4.8 kw) I have at home. So maybe the car's math estimates on how to reach 80% is based on the last charge rate, and errantly charged longer based on those recent rates of charge.

C) Maybe the car had some reboot/reset event, to trigger a 'fall back' to defaults. I don't know really that the default is 100%.

Has anyone else experienced this, or have insight into it? It's not a huge issue, but I don't want 100% charging as a normal state, naturally.

The culprit is the setting to 100%. For L2 charging the car queries the EVSE to determine the total power that can be supplied - it accurately detects a 20 amp 240 volt EVSE. That EVSE can provide up to 12 miles of range per hour charged.

 

There are a fair number of posts of this happening. It seems like a glitch that happens from time to time. It's gone past my 80% setting several times while charging at home @120v, but most of the time it doesn't

 

In support of (A), I must have had it set to "Charge Now" when I was at the public charger. I would not have set it to 100% though.

I checked now, and "charge later" is set at 80% and done by 330AM as expected.

So perhaps I left it on Charge Now....but I don't think I ever would leave it requesting 100%. It was definitely set to 100% on Charge Now when I got in the car today after charging.

Confusing, but not a major snag. It feels like a glitch but hard to prove that vs user error. Since my Blazer pal had it today too I'm wondering about commonality.

On the upside: my estimated range was 343 miles at 100%.

 

In support of (A), I must have had it set to "Charge Now" when I was at the public charger. I would not have set it to 100% though.

I checked now, and "charge later" is set at 80% and done by 330AM as expected.

So perhaps I left it on Charge Now....but I don't think I ever would leave it requesting 100%. It was definitely set to 100% on Charge Now when I got in the car today after charging.

Confusing, but not a major snag. It feels like a glitch but hard to prove that vs user error. Since my Blazer pal had it today too I'm wondering about commonality.

On the upside: my estimated range was 343 miles at 100%.

Given how much time GM put into building a common platform, I suspect every single GM BEV3 vehicle has this same glitch.

 

My wifes car has charged to 100% twice while set for 80%.
It also displayed 0% one day, until started even when it displayed several error codes which mysteriously disappeared when it "started".

 

This happened to me--0% SOC displayed, service high voltage--at the airport when I returned from a 3-day trip and it was about 15F. The car ran, the 3-day discharge was reasonable, and the alert disappeared eventually. I figured it was due to a battery sitting in the cold, but likely that combined with software logic errors interpreting the battery state.

 

I may have found an alternate explanation: my partial, but not complete, un- enrollment in Optiwatt. I enrolled as a trial in Jan but they never could master the 80% thing. I see that I am somehow still enrolled, and Optiwatt records that I was at 89% at 330 am.... That confirms they probably had something to do with it, since the car was set to achieve 80% at 330am. I had forgotten that they struggled with doing 80% vs 100% earlier.

So, probably not a bug in the car. It's Optiwatt. My Blazer pal l also reports the same thing.

 

Has anyone else experienced this, or have insight into it? It's not a huge issue, but I don't want 100% charging as a normal state, naturally.

Yes, it happened to me in the middle of last week. I also theorized it had to do with recent DC fast charging a 1-2 days earlier. I have a few instances where recent DC fast charging a 1-2 days earlier resulted in the car setting changing to 95%.

I recently posted about it here. Seems like a glitch to me that is a little troubling but I'm glad it is not going to 100% becuase my work commute is downhill an I don't want 100% SOC becuase it will impact my braking.

Hope GM figures it out soon.

 

My RST did this once. I checked the settings and it was at 80%. I don't know.

 

Suggestion was to reset settings in both the app and the vehicle to something else and back again to clear any corrupt schedules.

 

For me, I have no schedules....but the cause was almost certainly Optiwatt trying to do something smart and failing. It was my error for not disabling it fully earlier.

 

Yep, no schedules here either but next time I DC charge, I'll try to reset the app as well (or double check there is not a remnant item).

 

Yep, no schedules here either

Ditto.

 

This has happened to me a number times. Car was purchased on 10-15-25. I've taken to the dealer 4 times. I got it back this past Monday (4-28-25). Charging to 100% or 78% when it was set as always on 80%. 3 times taken in for "service vehicle soon" light being on. Remote start not operating with App or FOB. As of today (4-30-25), the "service vehicle soon" light is on AGAIN. A failed charge to 79%, not 80%. Every time the dealer has it, it's always "reprogram this" or "recalibrate that."

However, since getting it back from dealer on Monday, now the posted speed limit indicator has no readout. AND the XM radio is completely inoperative. (subscription is active.)
It's going back to dealer tomorrow, for the 5th time in 6 months.

Of interest, buried in the paperwork that received on 4-28, was the statement; "advised customer ( I wasn't told of this) that GM Engineering is aware of concern, and working on proper remedy." This statement was after mentioning overcharging issue and "system fault."

 

I had this happen once so far, it spike to like ~90%. I did notice this was after having the car for about 3 ish weeks. I do wonder if it is like, it more adjusting itself to my actual driving. For example, if I am getting higher miles per kwh than what is hard coded in. I think it realizes that my 80% range is not true anymore to the rated mileage (which is currently about 281-285 miles when I leave in the morning). Well if that is true, that is about 88-89% of the "rated" 319 miles. Which while that math doesn't 100% line up, I think at least points towards not an over charging (for me) but more it recognizing it can/does get more range than projected (which for me makes sense, I rarely drive on the highway and most of my driving is stop/go city driving going about 35 mph). Wonder if that explains some of random range spikes for some.

 

If I am reading your message correctly you think the SoC (%) is adjusting for the GoM (Guess-o-Meter). If anything, it should be the other way around.

The SoC should be based primarily on the voltage of the pack, with the voltage corresponding to some calibrated level of battery charge. The GoM is based on the SoC plus some formula which adjust for prior conditions and driving experience.

After all the 319 miles is not fixed-in-stone, but based on average driving conditions at a 100% SoC. It can be higher this time of year and maybe into summer, but lower in winter.

 

I don't know if this has been said yet, but I think I figured out why this happens. Like others, I have my charge session capped to 85%.

Yesterday, I had an update come through. I set it to install, turned the car off, exited, plugged in. Came out this morning, I'm at 100%.

I bet while the vehicle is updating software, it's bypassing the settings typically in place. This might be completely for the session or just if you happen to pass your cap while it's updating. I'm being it's the former, but both applied to me yesterday, so needs further testing to confirm.

 

Last week I charged to 65% at a public DC charger. When I got home there was a software update which I OK'd. When it was done the car was at 75% (unplugged on the street). I thought it was a glitch on the 75%, but after driving it several times this week it's at 64%. Is 75% the new 65%? When plugged into Level 1 at 8amps, it charges less than 1%/hr. Set to charge to 80%, my car has at times stopped at 83%--charging for more than three hours being the target. There just lousy software on this car.

 

This is more likely about how electric cars work, similar to Nissan and Tesla in this regard.

As temperatures warm, the battery capacity increases, so estimates of the next/current charge % are based on past data, but that past data was at different(probably colder temps).

That warmer outside temperature is why my car now said 337 miles of range (vs standard 319), and that 337 was pretty accurate too I feel.

 

Not quite the same but on Monday my car charged to 90% when it was set to 80 previously. I looked at it and the target was set to 90.

Tuesday I plugged it in and was about to set target to 80 and saw that it was set to 80 by itself.

Both was at home with location set.

 

2025 Equnox EV, Last Firmware Update: GM 652.30. 48A Charger/240V.
Was away for two weeks with car on charger. Set to charge to 80% charge level.
On 9/24/25, returned to find it charged to 100%.
First occurrence. Have not plugged in again yet to see if it reoccurs.

 

You should drive around a bit with some HVAC on to bring that 100% down closer to 80%, you know, for battery longevity sake.

 

I would not freak out about the 100%. It's not ideal but the car won't blow up. Just drive it as usual. The SOC% will drop. Now, keeping it at 100% every day, day after day is not a good strategy