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2019 Bolt built June 10th. 66kWh battery?
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I purchased my 2019 Bolt on 28 August 2019 (in Anchorage, Alaska). I installed a bluetooth OBDII reader and use Torque Pro, which logs and uploads my stats to forum user Telek, as far as I know (see Chevrolet Bolt OBD2 PIDs and related posts). I have noticed a few times that I seem to have significantly more than the nominal 60 kWh battery capacity listed for the 2019 model year. It seems possible that my 2019 Bolt has the 66 kWh battery pack that was installed starting in 2020.

I haven't written down any numbers (yet), but once I remember that the info screen indicator was reporting well over 30 kWh (32.xx?) used just as the capacity indicator on the dash switched from 55 to 50% (and torque pro was reporting 49.xx% and 48.xx% state of charge).

I have noticed that kWhs on the indicator tick backward when regenerating downhill, so it's not gross usage that is reported by the indicator on the info screen (kWh used plus kWh gained through regen since last charge).

Anyone else seem to notice significantly more battery capacity than 60 kWh for a pre-2020 Bolt? Just curious!
 

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It's possible that Chevy started using the 2020 packs in late model 2019 Bolt EVs (apparently, the modules are interchangeable, though that seems odd to me). The big difference might be the BMS, which enables a different charging profile

Just keep in mind, fresh Bolt EVs will show over 60 kWh usable initially, but I can't tell whether that is just the natural +/- 1 kWh deviation I've seen.
 

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Just keep in mind, fresh Bolt EVs will show over 60 kWh usable initially, but I can't tell whether that is just the natural +/- 1 kWh deviation I've seen.
When my battery pack was replaced last year, the new pack showed 61 or 62 kWh usable via the OBD data.
 

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2019 Bolt built June 10th. 66kWh battery?
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Discussion Starter #4 (Edited)
Understood about 61 or 62 kWh on a newer pack, and maybe that's what it is. I will use nearly a full charge tomorrow and Sunday, I'll keep track and post what I find..
(BTW, for 2019 models using OBDII readers, TorquePro doesn't display a correct "Battery Capacity Guess" ("Bat Cap Est") in kWh- it always displays -8.6)

OK- Nerd fest: I kept track of the numbers, as promised, and they show that I must have around 66 kWh capacity battery in my late 2019 Bolt. Cool! Check out how the numbers add up (divide out?) on your late 2019 Bolt and let me (us) know!
See below for details on calculations.

Both trips started with a full charge and I did not stop to charge along the way. I have had the car for 10 months and it now has around 8700 miles on it:

Trip 1 (235.1 miles):
54.2 kWh used,
At the end of the trip, in TorquePro the PID labeled: "SoC Raw HD" = 21%, ("State of Charge HD Raw") and
"Batt % DIC" = 17.3 % ("Battery Level Displayed").
(four green bars on the display = 20%)

That means that using SoC Raw HD, 1 minus 0.21 (0.79), divided into kWh used (54.2) should give the total battery capacity, which = 68.6 kWh (54.2/0.79)
and for "Batt % DIC" 1 minus 0.173 (0.827) divided by 54.2 = 65.54 kWh

Trip 2 (233.6 miles):
56.9 kWh used;
SoC Raw HD = 15.8% and
Batt % DIC = 11.8%
(three orange bars on display = 15%)

yields 67.58 kWh (56.9/0.842) and 64.51 kWh (56.9/0.882) respectively.
 

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2019 Bolt built June 10th. 66kWh battery?
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Discussion Starter #5
I saw another post about a sticker on the driver's side frame showing battery capacity. I looked and mine says 57 kWh, but I still don't beleve it!
 

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I saw another post about a sticker on the driver's side frame showing battery capacity. I looked and mine says 57 kWh, but I still don't beleve it!
It's simply the result of different rating procedures. On the official EPA documents, the 2017 to 2019 Chevy Bolt EVs are listed as 60 kWh.
 

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2019 Bolt built June 10th. 66kWh battery?
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Right, but my calculations using the actual kWh the 2019 Bolt used and the actual % charge remaining strongly point to the 2019 car having a 66 kWh pack!
 

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Right, but my calculations using the actual kWh the 2019 Bolt used and the actual % charge remaining strongly point to the 2019 car having a 66 kWh pack!
I agree. It's very likely that GM did start using the 66 kWh pack before the 2020 Chevy Bolt EV was released. They did something similar with the Volt, where late model 2012 Volt's received the larger 2013 Volt battery pack.
 

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2019 Bolt built June 10th. 66kWh battery?
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Interesting. How did those 2012 Volt owners know? And that they would have still affixed the old sticker showing 57 instead of 64 kWh
 

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I had a similar suspicion based on numbers from my first few long distance drives. That said, my 2019 is not late model (built in September, 2018). I really need to follow up with a test but my driving has been pretty minimal this year.
 

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I hear you about minimal driving. These are different times!
I'd be interested. An easy, and probably good enough, way to do a test is to charge up to reset the kWh used value, then notice the % charge indicator on the dash- as soon as it drops to a new level- 75% say- divide the kWh used value at that moment by 1- the percentage as a fraction...

In the example it's easy, just multiply kWh used by four: kWh/(1-0.75) = kWh/0.25 = kWh/1/4 = kWh used times 4. When it drops to 50% the calculation is really easy- multiply kWh used by two.

Perhaps all/many 2019's are 66kWh?? Maybe we are lab rats and GM was just testing the new battery chemistry?
 

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I hear you about minimal driving. These are different times!
I'd be interested. An easy, and probably good enough, way to do a test is to charge up to reset the kWh used value, then notice the % charge indicator on the dash- as soon as it drops to a new level- 75% say- divide the kWh used value at that moment by 1- the percentage as a fraction...

In the example it's easy, just multiply kWh used by four: kWh/(1-0.75) = kWh/0.25 = kWh/1/4 = kWh used times 4. When it drops to 50% the calculation is really easy- multiply kWh used by two.

Perhaps all/many 2019's are 66kWh?? Maybe we are lab rats and GM was just testing the new battery chemistry?
Using energy used plus battery % to calculate total energy only seems to be accurate if you've used a majority of the total capacity. For instance, your reading at 10% is going to be more accurate than your reading at 20% battery. I would consider anything over 50% battery to be very unreliable.
 

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2019 Bolt built June 10th. 66kWh battery?
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Like so many things in life and science, probably the accuracy of determining battery capacity is all about scale. I think, but would definitely be interested in your opinion on this, that for a quick evaluation of the capacity difference between 60 and 66 kWh, and not resorting to a deep dive into TorquePro, the quick-and-dirty method is probably sufficient. Read on...

I thought about it, and know that calculations assessing range (miles) or efficiency (W/mile or miles/kWh), would be sensitive to the range of the test, but wondered how the range of the test would apply to calculating capacity? A mile traveled uphill or downhill, or into the wind or with a tailwind, or through snow with winter tires vs dry pavement in the summertime, or a mile of range used is one thing; however, a kWh used is a pretty much an un-variable kWh used. (Except for temperature changes- which of course affect kWh battery capacity, which is not at all a fixed number).

I guess what I'm asking for is a convincing mechanism or example explaining why the accuracy would change enough to affect a calculation at the resolution of trying to determine if the size of the battery pack was 60 or 66 kWh? Even if a test was at an anamolous outside air temperature of 110 degrees F, the capacity probably wouldn't change enough to affect evaluation of the null hypothesis of: I have a 60 kWh battery pack? Maybe it would? Thank goodness I don't see those types of temperatures where I live!
Maybe I need a caveat: The quick-and-dirty test is reasonable one-time estimate if air temperatures are between about 50 and 90 degrees F? And, probably more importantly: it is much more accurate if you notice RIGHT when the indicator of battery % changes, AND what the display of kWh remaining shows exactly at that time? Still- easier than getting an OBDII bluetooth transmitter and installing Telek's custom PIDs into TorquePro...

If the null hypothesis being evaluated was something closer to: My battery pack has degraded by more than 3% or 5%, then longer tests and more tests would be necessary. With that finer degree of resolution, and the longer time period between the testing, the variation due to temperature would create enough noise in the data to require a more robust testing protocol to accuratley evaluate the smaller change. 0.03 x 60 = 1.8 kWh. I see almost that magnitude of variation at not very different temperatures- 60's vs 80's F. However, I haven't seen anything approaching 6 kWh in variation yet!

Other factors influencing capacity such as charge supply equipment, and charging frequency versus state (e.g. never charge past 80% or below 20% and always on level 1 charge equipment; or always charge to 100% and run down to 2% on DC fast chargers), and number of charge cycles require more time to affect capacity. Even considering these radically different long-term factors, the onboard charger and management software should go a long way toward preserving a lot of capacity for a long lifetime, as you have already shown. Thanks!
 

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Like so many things in life and science, probably the accuracy of determining battery capacity is all about scale. I think, but would definitely be interested in your opinion on this, that for a quick evaluation of the capacity difference between 60 and 66 kWh, and not resorting to a deep dive into TorquePro, the quick-and-dirty method is probably sufficient. Read on...

I thought about it, and know that calculations assessing range (miles) or efficiency (W/mile or miles/kWh), would be sensitive to the range of the test, but wondered how the range of the test would apply to calculating capacity? A mile traveled uphill or downhill, or into the wind or with a tailwind, or through snow with winter tires vs dry pavement in the summertime, or a mile of range used is one thing; however, a kWh used is a pretty much an un-variable kWh used. (Except for temperature changes- which of course affect kWh battery capacity, which is not at all a fixed number).

I guess what I'm asking for is a convincing mechanism or example explaining why the accuracy would change enough to affect a calculation at the resolution of trying to determine if the size of the battery pack was 60 or 66 kWh? Even if a test was at an anamolous outside air temperature of 110 degrees F, the capacity probably wouldn't change enough to affect evaluation of the null hypothesis of: I have a 60 kWh battery pack? Maybe it would? Thank goodness I don't see those types of temperatures where I live!
Maybe I need a caveat: The quick-and-dirty test is reasonable one-time estimate if air temperatures are between about 50 and 90 degrees F? And, probably more importantly: it is much more accurate if you notice RIGHT when the indicator of battery % changes, AND what the display of kWh remaining shows exactly at that time? Still- easier than getting an OBDII bluetooth transmitter and installing Telek's custom PIDs into TorquePro...

If the null hypothesis being evaluated was something closer to: My battery pack has degraded by more than 3% or 5%, then longer tests and more tests would be necessary. With that finer degree of resolution, and the longer time period between the testing, the variation due to temperature would create enough noise in the data to require a more robust testing protocol to accuratley evaluate the smaller change. 0.03 x 60 = 1.8 kWh. I see almost that magnitude of variation at not very different temperatures- 60's vs 80's F. However, I haven't seen anything approaching 6 kWh in variation yet!

Other factors influencing capacity such as charge supply equipment, and charging frequency versus state (e.g. never charge past 80% or below 20% and always on level 1 charge equipment; or always charge to 100% and run down to 2% on DC fast chargers), and number of charge cycles require more time to affect capacity. Even considering these radically different long-term factors, the onboard charger and management software should go a long way toward preserving a lot of capacity for a long lifetime, as you have already shown. Thanks!
It's certainly possible that a battery with zero lost capacity reports more consistently at higher SoC, but that has not been my experience. Even early on, if I only discharged my battery 50% or less, the energy capacity estimates would vary widely. +/- ~5 kWh if memory serves.

You definitely need to cycle the full battery early on just to ensure that you don't have any bad cells, but even just for accurate measurements, you really need to do multiple cycles to account for discrepancies.
 

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Using energy used plus battery % to calculate total energy only seems to be accurate if you've used a majority of the total capacity. For instance, your reading at 10% is going to be more accurate than your reading at 20% battery. I would consider anything over 50% battery to be very unreliable.
One of the reasons for this is that the raw-to-displayed SoC correlation curve is not linear, but more like a slight "S". Actual kWh consumed per 10% of displayed usage above 50% SoC is more than that of below 50%, i.e. the displayed SoC will drop faster below 50% even if you use the same amount of energy.

Because of this issue, I keep track of the usable capacity based on SoC-kWh relation with a 14-day moving average. It smooths out those differences.

30052
 

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To simplify the battery estimate and get visibility with some confidence intervals try this

  1. Make sure you can read the percentage SoC from the MyChevrolet app or another tool. If the MyChevrolet app works for you, don't dive too deeply into Torque pro.
  2. Locate the kWh and miles used screen (Usually the home screen)
  3. Make a simple paper table with two columns: SoC, and kWh used
  4. Start at any SoC, preferably over 85%
  5. Drive, and record at reasonable SoC intervals: SoC, and kWh used
  6. Collect data over several days without recharging, or on one day where you have reason to get to lower SoC.
  7. Enter the data as two columns in Excel, Google Sheets, Open Office, etc.
  8. Use the x-y chart function to graph the data into information
  9. Ask the spreadsheet to add a TRENDLINE to the data
  10. Use the LINEST function to derive standard errors for the estimates.
Here is a screenshot of a recent drive from Portland, Maine to Hartford, Connecticut (204 miles). I was not horribly disciplined, and took data at rounded SoC intervals. (Watch the app until the percentage I wanted clicked over and then changed to the home screen to record the kWh used.)

30051

And the corresponding data and statistical information

SoC (%) from My Chevrolet appkWh used from home screen
100%0.0
80%11.6
50%28.7
35%37.4
Low estimateHigh estimate
>97.8% confidence z=257.1557.74kWh
Slope and Intercept-57.4557.48
Standard Errors (1 SD)0.150.10
R-squared1.000.07
Other statistical functions154842.252.00
847.680.01


As @NewsCoulomb notes, if your battery has low spots these will show up as non-linearities in the plotted line. Again, I did not drive to 5% because I have done full tests and really have not seen this effect to any great degree. (I do see some deviations downwards below 35%, but as of yet these are small.)

In this method, the slope and intercept should be equal except for non linearities. The test above shows 57.45 and 57.48, very close with some non-linearity below 40% (from the graph). The consumption from 100%-35% implies a battery capacity of ~57.6 kWh, an acceptable level to me after 57,000 miles.

The standard errors for the coefficients are also close. Using the larger of the two of 0.15, doubling it for a z-value of 2, I get that my battery has between 57.15 and 57.48 kWh capacity (at 97.8% confidence level).

Again, this simple method used the existing vehicle indicators and an app, gives useful data with as little as 3 data points, and generates a visual and mathematical indication of non-linearities. If you have the LINEST statistical functions available the method also gives you a confidence level.

Realistically, if you were fortunate enough to get an updated battery before the model year, wonderful! The statistics in this method will be plenty sensitive to see the a 6kWh difference.

Good testing!
 

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I got my 2019 in June 2019 and it was built in March. I've not driven mine below 50% so far but in the couple calculations I've done, I get around 59.5 kWh capacity. Don't know what that means.

Mike
 

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I got my 2019 in June 2019 and it was built in March. I've not driven mine below 50% so far but in the couple calculations I've done, I get around 59.5 kWh capacity. Don't know what that means.

Mike
It means that your 2019 likely has the previous generation battery. It might be possible to narrow down when GM started using the updated packs in the Chevrolet Bolt EV by check build dates. It does make sense that they started using them for the MY 2019 because battery supply has always been the constraint for Bolt EV production. Several owners have even reported getting MY 2017-2019 modules replaced with MY 2020 Bolt EV modules.
 

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This is the scenario that got me wondering. I drove 185.8 miles (starting at 100%) using 56.2 kWh. The display said I had 34 miles left (minimum 27) with the trip average being 3.3 mi/kWh. The battery level was at 15% - which could in theory be as low as 11% because of how it's displayed. I calculated two different ways - one assuming I would get 3.3 mi/kWh for the remaining 27-34 miles and one where I calculated 56.2 kWh being 85-89% of the battery. Both calculations gave me answers ranging from 63 to 66 kWh pack.
 
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