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2019 Bolt built June 10th. 66kWh battery?
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Discussion Starter #81
For those that may be interested in comparing their capacity estimates, I have recorded data from 2 trips that used only the top 50% or so of the battery SoC, but one was the lowest estimate yet (62.38 kWh. The other was 65.01 kWh). The low estimate comes with a curious observation.

Details:
141.3 miles driven
33.0 kWh used
Ending DIC SoC (from TorquePro): 0.471
Capacity estimate: 62.38 kWh
Air Temp: 30s-50s F

125.2 miles driven
30.1 kWh Used
Ending DIC SoC: 0.537
Capacity estimate: 65.01 kWh
Air Temp: 50s F

I am especially interested in similarly derived estimates from folks with 2020 and newer Bolts.

The low air temperature at the start of the first trip seems the likely cause of the lowest capacity estimate yet. However, I also noticed that the level on the dash indicator was very close to 50% when the car was switched off after I pulled into the charging station: The dashboard indicator light had just dropped to that level when kWh Used was reading 32.9 (which gives a capacity estimate of 65.8 kWh). But when I switched the car back on to look at the numbers from TorquePro, I was surprised to see the DIC value of only 47.1%.

I can think of two possibilities for this seemingly too-low value: Perhaps the sudden power use of switching the car off and back on biased the TorquePro SoC DIC % value some way without changing the car's display of kWh Used? Alternatively, maybe the low estimate really was due to the low air temperature and the dashboard display doesn't necessarily blink down to 50% at the same "SoC DIC %" level every time?

So, like NewsColumb and others have pointed out, this capacity-estimating business is pretty imprecise. Even over the same exact conditions, a seemingly minor change in estimation method produces values over 5% apart: 65.8 and 62.38 kWh! Values in this range still seem solidly above the values that anyone has obtained with a 60 kWh battery pack, although my lowest estimate, 62.38, might overlap with their highest estimates using SoC DIC %? Standardizing estimation methodology would eliminate some of the variability.
 

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Alternatively, maybe the low estimate really was due to the low air temperature and the dashboard display doesn't necessarily blink down to 50% at the same "SoC DIC %" level every time?
Correct...two for two. I have observed both of these to be true.
 

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2019 Bolt built June 10th. 66kWh battery?
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Discussion Starter #85
More data:
One more trip, about 228 miles, low 50s F, rainy in part. Since last charge to full:
kWh used: 56.6
Charge remaining (TorquePro SoC DIC): 12.9%
kWh Capacity Estimate: 64.98

Another trip, about 150 miles, very rainy and high winds (tailwinds and headwinds), ~50 F, heater and defroster on a lot:
kWh Used: 42.7
% Charge remaining: 34.5
kWh Capacity Estimate: 65.19

On the first trip, to the dealer to get the main fuse replaced due to recall (quick and easy once they received the part), the above numbers reflect the trip to the dealership- draining the full battery down to 12.9%. After that, I went into "NewsColoumb Mode"- ready to run it as low as I felt comfortable, since I was in the big city and chargers were nearby. The car was started and stopped five times, and driven less than 20 miles (didn't record that data). This used 2.9 kWh, but that 2.9 kWh used reduced the DIC SoC by 9.4%, down to 3.5%. If I include those numbers for the last 2.9 kWh Used in the total capacity estimate for the entire trip, the estimate drops to 61.66 kWh!

Therefore, switching the car off and on reduced the % estimate of DIC SoC in much greater proportion than the reporting of kWh used. In other words, the software seems to estimate battery % remaining independently from kWh Used. This begs the question: does switching the car off and on (especially at a low state-of-charge) really kill the battery capacity for that charge cycle, or is the indicator being too conservative, and I could have actually driven much further than shown. The dash reported the range remaining as "Minimum", the single bar on the dash showing battery % was flashing orange and the display read: "Propulsion Reduced". I have a strong feeling that the former is true: battery capacity is greatly reduced by switching the car off and on, at least at low states-of-charge.
I assume that if I had not stopped at the dealer or for other errands, and continued driving around I would have retained much more capacity. If you are running low- keep going until you reach that charger (he says hopefully)!
 

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Isn't it a lot easier just to read "miles traveled" and "kWh used" directly from the energy information screen in the car?
Yes, if you are in your car. With the app, you can be anywhere, like inside your house. :)
 

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2019 Bolt built June 10th. 66kWh battery?
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Discussion Starter #87
Isn't it a lot easier just to read "miles traveled" and "kWh used" directly from the energy information screen in the car?
And especially when you get the message that the app does not work with all phones...
 
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