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More range with Bolt Software fix?

9945 Views 46 Replies 23 Participants Last post by  csandoval012
I have a 2019 Bolt that was part of the battery recall. Prior to having the update done, I was showing about 238 mile range after a full charge (prior to limiting the charge to 90%).
After the update, I am seeing a 254 mile range after a full charge. Has anyone else noticed a change in full charge range after the update?
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Hello from Canada. I had my Bolt in to the nearest dealer who can work on them, only 400 km away. They did the battery update on my 2019 Bolt due to the recall because of fire risk. It's still early days after that, but it appears that we have lost considerable range. We used to average about 16 kWh/100 km in the summer and 23 kWh/ 100 km in the winter, when we also have a roof rack on for skis. Has anyone else experienced that?
Can you clarify? You gave your previous efficiency numbers - what are they now?

Some owners have reported that their settings / preferences were reset after the software update. Is your auto defog setting on?
My consumption was about 16 kWh/ 100 km in the summer before the patch, with no roof rack on. Now it's about 20 kWh/ 100 km. No, I cannot see auto defog, and that should not make such a big difference. But I'll check that.
Can't hurt to check the other usual suspects for lost efficiency - tire pressures, brake issues, airflow issues under the car, etc. Has it been particularly windy recently?

If you have an ODB2 reader, you could look at the battery temperatures and the battery coolant pump speed, as well as the cabin heater and air conditioning power draw. I'm having a hard time seeing how a software change would reduce the car's overall efficiency. The motor is the same, the power electronics are the same, the aerodynamics are the same, etc. A 25% hit to efficiency from pure software seems unlikely, unless something like the battery coolant system or the cabin air conditioning system is constantly running...?
So...I'm pretty new to this, I just bought my used 2017 about 3 months ago. When I got it it had already had the software update that eliminated the hilltop reserve option. I drive 158 miles round trip to work every day and have been able to make the journey no problem even went 170 and still showed 30ish miles left on the GOM. Most of my drive is 70-75 with a short stint on the interstate and 24 miles of slowish (55 mph).

I just had the recall done on Monday, and I charged the car all the way to full yesterday, and on my drive and it seemed to result in the same distance/kWh as what I was getting before with the Hilltop Reserve permanently on.

Last night I turned the Hilltop Reserve back on and charged the car. So...today I'm at work and I'm half way through the batt capacity (which is more than ever before), and I'm a bit concerned that after the update either my capacity now is reduced (Current 100% charge is akin to the HTR from before the update) OR the miles per kWh is reduced...either way, I'm not happy because my drive is on the outer limits of the capability AND it means Chevrolet sold it with one set of statistics only to reduce it with this software.

Anyways....I'm going to watch this over the next few days, and construct my "discussion" I plan to have with the service manager and probably the corporate office if this turns out to be what I suspect.
The update may have reset your comfort and climate settings. Make sure auto defog is turned off - that can run your A/C and heat without any visible indication. Also can't hurt to check your tire pressures.
Just got my update done. Prior to applying the 90% update, I was consistently getting 220-240 on a full charge. The first charge after the latest update only got to 185. I will give it a little time to settle out. Is there any way to confirm that the software update was applied successfully?
Welcome to the forum!

Did you get the temporary fix before this one? If so, is the hilltop reserve setting back? If so, you got the final fix (which restores the hilltop reserve setting taken away by the temporary fix).

Reports from others indicate that the range estimate is all over the map after the software update (some higher, some lower), because the battery management system (BMS) was reset. You may need to charge to 100% and drive to a pretty low state of charge a few times for the BMS to relearn the specifics of your battery and show a relatively accurate range again.
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I am new to this forum, but not new to electric car driving. I have a 2016 Chevy Volt and a 2019 Chevy Bolt. I have been driving my Bolt for over two years. As a former Air Force pilot, I am very detailed in recording my energy consumption and range. Prior to the software update for the possible fire risk, my car was all within expected parameters. As of the update in mid-May 2021, it is no longer accurate.

I have been working with GM to try to get them to understand the problem, but I have not heard from them for some time now. Below is what I submitted to my Chevy dealer which is the only avenue that I have for getting info to GM:

2019 Chevy Bolt​
Before the May 2021 software update for battery fire prevention everything was normal
After the software update the energy consumption readings are significantly off, and as a result the range estimates for the car are also significantly off. Both are now significantly incorrect.
As a baseline, here are some electric car energy efficiencies as measured by the EPA:

Most energy efficient: Hyundai Ionic - 248 watts/mile
Tesla Model 3 RWD - 259 watts/mile
Chevy Bolt - 283 watts/mile
Least energy efficient: Jaguar I-PACE - 443 watts/mile

Manufacturers like Chevy usually display that on the instrument panel as miles per kWh. For the 2019 Chevy Bolt the standard that is displayed after a full charge is 3.9 mi/kWh. Thus, the 3.9 is the normal miles that you can expect from the EPA rated 238-mile Bolt. I usually can get a bit better at around 4.2 mi/kWh in my normal driving. At highway speeds it will drop below that to around 3.5 mi/kWh.

I have analyzed this energy consumption and range every day for the over two years I have had my Bolt.
Here is a comparison of my driving readouts before and after the software update:

Before the software update After the software update
Read out: 4.2 mi/kWh 7.9 mi/kWh
Watts/mi 235 127
Range @ 60% charge 145 245

Since the new readout of watts per mile is roughly half of the most efficient electric production car, it is clearly not correct. In fact, I have verified that I am still getting roughly 4.2 mi/kWh by calculating the % SOC at the beginning of my driving and subtracting the ending SOC to determine energy consumed over the miles driven. This method is not quite as precise as the readout, but it does confirm that my car is still performing as certified by Chevy and the EPA. Thus, the battery appears to be fine, as well as the SOC readings and the time to charge readouts. I do suspect that any battery diagnostics will show nominal battery readouts.

Ramifications:
For me it is mostly an annoyance for local driving since I am confident in my SOC readouts. On a long trip with planned charging, even for me I am not happy because I cannot get real time readouts of my energy consumption. Forget the range displayed in miles, it is totally worthless.

For others who do not have as much technical knowledge of electric cars, at first it would be mostly happiness that they now have so much more range on their cars. That is until they take a trip counting on that range and end up out of energy on the side of the road.

For GM and Chevy, a potentially huge downside as they have not elected to replace batteries with the bad separators as did Hyundai and Kia. Their reputation is riding on this battery software update, and it is currently messed up (perhaps only in my car, but I suspect not). It is my hope that I can help provide enough information to the software engineers so that they can debug their program. A lot is riding on getting this fixed quickly and correctly鈥
How many miles have you driven since the software update? Have you charged back to 100% since the update? There have been similar reports that the battery management system was reset and needs to relearn. It may take a few charges to 100% and drives to low SOC.

Having said that, there's at least one report of the software not relearning correctly, and another report of the update being installed incorrectly as determined by another dealership. If you have an ODB2 reader with Torque Pro, you can gather more detailed data to use with the dealership or the Chevy concierge.
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