Bolt EV powers down while driving, with "Minimum" 15 miles charge remaining

[GoldenZephyr]

This past weekend, I drove my three month old Bolt on a roundtrip of a few hundred miles. Charging along the way was an issue (given the cold weather in the northeast right now, a full charge displays as an "average" predicted range of about 185 miles), but I used the heater very sparingly and made sure to always leave a mileage cushion to avoid getting stranded along the side of the road due to a depleted battery.

However, on the return drive, when I was about 3 miles from home and the charge/range display showed a "minimum" 15 mile range remaining (see dashboard photo), the message "Charge Vehicle Soon" displayed and the Bolt abruptly came to a complete stop. This occurred while driving up a steep, snow-covered stretch of road, and left my vehicle stationary in the middle of its lane, an incredibly unsafe situation.

I called AAA, thinking the battery was depleted, regardless of what the range indicator showed. But they were unresponsive, and so in desperation I tried a few things, ultimately discovering that simply dismissing the useless "Charge Vehicle Soon" message using the "checkmark" button on the steering wheel restored vehicle power and allowed me to drive the rest of the way home.

So apparently what happened is that when the car reached about 8% battery power (15 miles remaining divided by 185 at a full charge), it automatically dropped into some sort of low power mode that left it unable to climb a hill. This is an insane "feature". Even with the driver able to restore full power by dismissing the warning message, programming the vehicle to essentially turn itself off while travelling at speed, is a terrible idea. Thankfully in this case, the roads were almost deserted and no one was hurt, but obviously the potential for an accident is very high when a vehicle suddenly stops in the middle of a road.

I would like to add that this vehicle behavior is not described in the owner's manual. On page 231, it is stated that at some point when the battery's charge is very low, a "Propulsion Power is Reduced" message will display and the "accelerator pedal response is reduced". However, the following sentence reads, "In addition, the remaining range value will change to LOW indicating the vehicle should be charged immediately." That never happened in my case. The "Propulsion Power is Reduced" message never displayed (though propulsion power clearly was reduced), and as can be clearly seen in the posted photo, the MINIMUM range displayed as 15 miles. That was five times the remaining distance to my home, and there was no conceivable reason for the car to shut down with that mileage remaining.

I would like a response from Chevrolet regarding this issue. Is this "normal" behavior for the Bolt? If so, can it be disabled? It's bad enough that the advertised 238-mile range drops into the 180's during the Winter, even with almost no use of the heater (only intermittently for windshield defrost purposes; otherwise I only use the heated steering wheel and front seats, at a minimal energy cost of about 1 kW). To then be denied safe use of the last 15 miles of range (dropping me to about 170 miles, if I don't want to find myself suddenly losing power while driving), for no reason I can think of (how does this improve safety or utility?), only adds insult to injury.

 

[gpsman]

It’s not a feature. It’s probably a one time glitch.

Mine does not behave like that.
Mine did just as the manual says.
I’ve gone down to one Orange Bar.
Then maximum power was reduced, but the car was very driveable (at city speeds).

 

[DNAinaGoodWay]

One heck of a glitch!

Go here: https://www-odi.nhtsa.dot.gov/VehicleComplaint/

Things like this need to be documented.

 

[GoldenZephyr]

It’s not a feature. It’s probably a one time glitch.

Mine does not behave like that.
Mine did just as the manual says.
I’ve gone down to one Orange Bar.
Then maximum power was reduced, but the car was very driveable (at city speeds).

It's obviously a pretty big deal, and whether it's a "one time" glitch or not very much remains to be seen.

Even if my car behaved as described in the owner's manual, which it does not, that would be unsafe. How is it helpful for the car to power down when low on battery charge? Does that increase the driver's chances of safely reaching a charging station? I could understand the car automatically turning off the heater, for example, but reducing accelerator pedal response is always a bad idea, and will inevitably lead to traffic accidents. Most drivers follow the vehicles in front of them too closely, and unexpected slowing and stopping leads to rear-end collisions.

 

[BoltMaybe]

Even if my car behaved as described in the owner's manual, which it does not, that would be unsafe. How is it helpful for the car to power down when low on battery charge? Does that increase the driver's chances of safely reaching a charging station? I could understand the car automatically turning off the heater, for example, but reducing accelerator pedal response is always a bad idea, and will inevitably lead to traffic accidents. Most drivers follow the vehicles in front of them too closely, and unexpected slowing and stopping leads to rear-end collisions.

This power reduction is common for an EV, but not without several warnings and certainly not with 15mi left. The idea is that, if you reduce to golf cart speeds, you can get another mile or two more than driving normally. Tesla cars, like the Mercedes B-Class have a reserve button that you push which will get you another 3-5mi of normal driving, but if you don't push it, you get the 20mi max speed like the other EVs. Is it dangerous? Well hate to say it but when you run out of gas in an ICE you don't get an extra mile at 20mi/hr. You stop, pretty much as you did if not worse. In this instance you suffered the same condition as a broken fuel gauge in an ICE: you ran out of gas when the gauge said there was a gallon left in the tank. Not cool in any car regardless of whether it's an ICE or an EV and "glitch" is too mild a word for sure. .

Since others have not experienced what you have and it is not what is documented in the manual, it is a straight up bug triggered by some state that your Bolt got into. Hopefully your dealer can check the diagnostics on the CANBus for information as to what that condition was, how your Bolt got to that state, and report the bug to the folks at Chevy.

In the meantime I would definitely follow the link supplied by DNAinaGoodWay because, as you say, this is a definite hazard which will cause an accident some time soon (especially if it is common in cold weather). You had no warning that you were going to lose power and that is not acceptable.

Whether it gets fixed is another story, especially given the dismantling of "excessive regulation" that our current government is performing on a wholesale basis. I am certainly going to make sure I have "plenty left in my tank" from now on.

 

[DNAinaGoodWay]

Yes, please make a full report to the NHSTA as well as GM and let us know what happens. New Technology vehicles present new engineering challenges and we need to resolve problems before anyone is killed or injured. Thanks.

 

[SmokingRubber]

It likely had a lot to do with the fact you were driving up a steep hill. I suspect that drastically changed your range and put you in the danger zone sooner than it thought you would be.

I driven mine to 8 miles range remaining, and it came with several warnings to "get off the freeway and charge your $hit you stupid m&%$@# f&%@&%"! It was probably just about to start cussing you out then you hit the hill and it lost all patience.

The sad part is, the battery isn't drained when it says it's empty. It's not SAFE to drain it further, but technically there is reserve. Example: I use LiPo batteries on my RC cars and RC planes. Using a meter on the battery tells me how many amps I've got in the battery. It doesn't say full or empty it says 4.20 when its completely full and drains to about 3.80 when I need to recharge. I've taken them lower than 3.80, but technically I need to recharge very soon. I don't know what the safe range on the Bolt is, but I'm willing to bet we could get more range with a software update. That might harm the life of the battery, but if it didn't stay drained for too long it would be ok.

They just need to educate people on how to properly maintain EV batteries. You can't treat it like an ICE vehicle where it's always empty and you plunk $5 lunch money in the tank every time you want to go somewhere. The rules are different. I'm not saying I know the rules any better than anyone else does, I'm just saying there should be a source of solid information.

 

[GoldenZephyr]

What was interesting in my case is that the car resumed normal power once I dismissed the "Charge Vehicle Soon" message. Nothing in the owner's manual indicates that simply dismissing the more ominous "Propulsion Power is Reduced" message, which never displayed for me but is supposed to be coincident with "accelerator pedal response" being reduced (exactly what happened in my case), returns the car to normal driving conditions. So it is all very odd.

I did file the report with NHTSA, using the form linked to in one of the replies. If anyone else experiences anything like this, please do the same. The reporting link follows:

https://www-odi.nhtsa.dot.gov/VehicleComplaint/

I get the impression from the NHTSA website that they do not actually do any investigating unless multiple reports of the same problem are received. In the meantime, I'm driving under the assumption that I only have about 90% of the range that my Bolt tells me I have, since even though I can "dismiss" this particular problem by pressing a button on the steering wheel, I don't want to experience such a loss of power while driving again. The steep hill may well have been part of the problem, but given that the appropriate warning message ("Propulsion Power is Reduced") never displayed, I'm not convinced that the battery charge actually hit the threshold that is supposed to trigger power down. For whatever reason, my Bolt's software seems to trigger that state in advance of when it is supposed to occur.

 

[gpsman]

Apparently some people in this thread feel gasoline powered cars are much more reliable.

They probably feel gasoline cars never stall unexpectedly. That gasolone cars never run out of gas unexpectedly. That gasoline cars never have a battery go dead unexpextedly. Never have an altermator quit working unexpectedly. And of course, they never ever get a flat tire.

:roll:

Probably you should sell your Bolt right away. It’s much too dangerous of a car for you. In fact, you should probably turn in your driver’s licence too. Being able to deal with unexpected problems in real-time is part of the requirement of being a responsible driver.

What you should do is post on here: “Hey, this happened to me the other day, did this ever happen to anyone else?” And collect information collaboratively. Shouting “the sky is falling” and “this car is going to kill people” is completely inappropriate.

 

[oilerlord]

And of course, they never ever get a flat tire.

EV's don't get flat tires, however they ARE prone to "sudden tire failure".

The OP's issue could simply have happened due to a low 12V battery. If he's so concerned, just take the car in for service, and do the board a solid by reporting back. Who knows, there may be a TSB on this.

 

[GoldenZephyr]

And of course, they never ever get a flat tire.

EV's don't get flat tires, however they ARE prone to "sudden tire failure".

The OP's issue could simply have happened due to a low 12V battery. If he's so concerned, just take the car in for service, and do the board a solid by reporting back. Who knows, there may be a TSB on this.

Ok, it obviously wasn't due to a low 12V battery. Dismissing the warning message restored full power, which wouldn't have worked if the 12V battery was low.

As for cars randomly losing power while at speed on the open road, that's clearly a safety issue. Drivers don't expect the cars in front of them to suddenly slow down, especially in the absence of brake lights or turn signals. It's not remotely paranoid to imagine this behavior leading to rear-end collisions. Imagine losing power in the middle of an intersection!

Now power loss would be expected when the high-voltage battery is depleted. Not when the gauge shows a minimum of 15 miles remaining. This is clearly a software issue. There's no need to be an apologist for bad programming.

 

[SeanNelson]

Ok, it obviously wasn't due to a low 12V battery. Dismissing the warning message restored full power, which wouldn't have worked if the 12V battery was low.

While I agree that it seems unlikely, it's still possible that a low 12V battery caused some funky condition to be set somewhere that then eventually triggered the reduced propulsion power. 12V battery issues can be a real source of gremlins for battery and hybrid electric vehicles.

 

[GoldenZephyr]

Ok, it obviously wasn't due to a low 12V battery. Dismissing the warning message restored full power, which wouldn't have worked if the 12V battery was low.

While I agree that it seems unlikely, it's still possible that a low 12V battery caused some funky condition to be set somewhere that then eventually triggered the reduced propulsion power. 12V battery issues can be a real source of gremlins for battery and hybrid electric vehicles.

Hmm. I've always assumed that the 12V battery was kept fully charged by the main battery pack. I also never received any sort of error message regarding the 12V battery.

My bigger concern at the moment is my "fully charged" Bolt showing a median predicted range of 169 miles. I'm not sure where the oft-quoted 238-mile range figure originates. Maybe all downhill, with no curves, no AC, and no heat? And this is from someone who uses the regen paddle at every opportunity, and forgoes the heater (even when it's 0 degrees outside), except for intermittent windshield defrosting purposes. The combination of predicted mileage in the mid-100's, and being unable to use the last 10% or so of the battery charge without hitting the "power down" error, effectively makes this a 150-mile range vehicle.

 

[LeftieBiker]

My bigger concern at the moment is my "fully charged" Bolt showing a median predicted range of 169 miles. I'm not sure where the oft-quoted 238-mile range figure originates. Maybe all downhill, with no curves, no AC, and no heat? And this is from someone who uses the regen paddle at every opportunity, and forgoes the heater (even when it's 0 degrees outside), except for intermittent windshield defrosting purposes. The combination of predicted mileage in the mid-100's, and being unable to use the last 10% or so of the battery charge without hitting the "power down" error, effectively makes this a 150-mile range vehicle.

EVs are generally range tested in mild weather, with no heat or A/C. Some newer tests include some use of both, but in general range figures are to be taken as "in mild weather, at moderate speeds." It is accurate to say that in Winter, the Bolt is a 150 mile EV. My Leaf is currently a "42 mile EV." When it warms up this week it will be a "50 mile EV."

 

[SeanNelson]

Hmm. I've always assumed that the 12V battery was kept fully charged by the main battery pack. I also never received any sort of error message regarding the 12V battery.

The charging protocol for the 12V battery is a lot more complex than you might expect. It's not the case that the battery is charged continuously - when the car is turned off the onboard computers check the battery state of charge only periodically and on an ever-increasing interval, and they only charge it for a set amount of time upon each check.

If the car was sitting untouched on some dealer's lot for several months, the battery may have run down enough to damage it to the point where it won't hold a proper charge even when the car is left for just a couple of days.

If the battery is low, it can lead to funky readings from the vehicle sensors which then result in mysterious codes or conditions that are extremely difficult to troubleshoot. That's why checking the 12V battery is almost always recommended whenever you see weird things happening with the vehicle.

None of this is peculiar to the Bolt - if you frequent other BEV or Hybrid forums such as those for the Prius you'll see much the same kind of discussions. It's the result of electric drive - you don't need a honking big battery to turn over the engine, but at the same time you've got these control computers that always place a drain on the battery and which tend to go a little strange if the voltages get too low.

 

[GetOffYourGas]

Ok, it obviously wasn't due to a low 12V battery. Dismissing the warning message restored full power, which wouldn't have worked if the 12V battery was low.

While I agree that it seems unlikely, it's still possible that a low 12V battery caused some funky condition to be set somewhere that then eventually triggered the reduced propulsion power. 12V battery issues can be a real source of gremlins for battery and hybrid electric vehicles.

Hmm. I've always assumed that the 12V battery was kept fully charged by the main battery pack. I also never received any sort of error message regarding the 12V battery.

My bigger concern at the moment is my "fully charged" Bolt showing a median predicted range of 169 miles. I'm not sure where the oft-quoted 238-mile range figure originates. Maybe all downhill, with no curves, no AC, and no heat? And this is from someone who uses the regen paddle at every opportunity, and forgoes the heater (even when it's 0 degrees outside), except for intermittent windshield defrosting purposes. The combination of predicted mileage in the mid-100's, and being unable to use the last 10% or so of the battery charge without hitting the "power down" error, effectively makes this a 150-mile range vehicle.

Yup, unfortunately that's completely normal for any BEV. All cars are less efficient in the cold. Cold air is denser, causing more drag. There may be snow or slush on the road, causing more drag. In addition, BEVs don't have "free" heat from an inefficient engine, so they have to generate heat from battery power. PLUS batteries hold less energy when they are cold, so you have less energy to begin with.

In my climate (Syracuse, NY), I figure that my Bolt has, at worst case, a 100-mile range. That's dead of winter, plowing through snow, running the heat, etc. I also know from experience that during warm weather, my car will easily travel the 238 miles or more driving 65 MPH down the highway with the A/C running (contrary to ICEV experience, the A/C adds very little load whereas the heat is what really kills your range).

 

[GoldenZephyr]

Yes, 100 mile range (running heat full blast), or 150 mile range using it only for windshield defrosting sounds about right in the northeast, during Winter. 100 or even 150 miles is not equivalent to 238 miles, however, and an approximate Winter range (say, road tested at 32 degrees, with interior heat running and thermostat set at 62 degrees), would be extremely helpful information to have posted on the car's window decal while it sits in a dealer's lot. About 170 miles before sudden power loss was all my Bolt could achieve on my recent trip, without the heat on except for defrosting. It was a depressing drive, made more so by the fact that the interior car temperature hovered near the below-freezing exterior temp (because I kept the heat off to conserve power). It was like driving through a snowstorm in a convertible.

The current situation, in which only the 238-mile figure is quoted, would be equivalent to the window decals on ICE cars mentioning only the highway MPG, without even noting that it's the highway MPG. Actually, it's worse than that, since having your ICE car run out of gas sooner than you expect just means looking for a ubiquitous gas station for a 5-minute fill-up, whereas when your BEV runs out of charge prematurely, you're probably calling for a tow truck...

I imagine that in a few years, when regulators catch up to the issues specific to BEV's, there will be a requirement for more realistic and detailed range estimates to be provided by manufacturers. Until then, unless you live in CA or some other "not too hot, not too cold" part of the country, it's definitely a case of caveat emptor.

 

[LeftieBiker]

All true. In the meantime, I suggest we tell people that an EV has "about half" the range in Winter as in mild weather, or half what is posted as the official range..

 

[DNAinaGoodWay]

There’s a couple more reports on the Facebook group of this OP’s problem. Both early builds under the recall. New packs installed, issue resolved.

 

[winterescape]

There’s a couple more reports on the Facebook group of this OP’s problem. Both early builds under the recall. New packs installed, issue resolved.

Good to know, thanks for the updated info