What was the average m/kWh or kWh/100 km in both cases : 50% and 10% ?I got a new battery in my 2017 Bolt 4 days ago and did my first capacity check using OBD-2 codes from Sean Graham (thank you Sean). I'm wondering if this looks reasonable and whether I did the test correctly. Here are what I think the critical codes are at 100%, 50%, and 10% SoC:
View attachment 39907
The kWh used values come from the infotainment screen. My calculations estimate the capacity between 58 - 62 kWh with the battery temp in the mid 50s F. If 70 F yields the highest capacity, and according to Sean's FAQ the capacity drops about 1% per 2 F below 70 F, I need to add about 7% to get the capacity under ideal conditions. Assuming the kWh at 10% SoC is more accurate, then the capacity should be around 62 kWh (58 kWh X 1.07%). Does this all make sense? Thanks in advance.
-
Hey Guest, welcome to ChevyBolt.org. We encourage you to register to engage in conversations about your Bolt.
New Battery capacity check using OBD-2
I got a new battery in my 2017 Bolt 4 days ago and did my first capacity check using OBD-2 codes from Sean Graham (thank you Sean). I'm wondering if this looks reasonable and whether I did the test correctly. Here are what I think the critical codes are at 100%, 50%, and 10% SoC:
![Font Rectangle Screenshot Number Parallel]()
The kWh used values come from the infotainment screen. My calculations estimate the capacity between 58 - 62 kWh with the battery temp in the mid 50s F. If 70 F yields the highest capacity, and according to Sean's FAQ the capacity drops about 1% per 2 F below 70 F, I need to add about 7% to get the capacity under ideal conditions. Assuming the kWh at 10% SoC is more accurate, then the capacity should be around 62 kWh (58 kWh X 1.07%). Does this all make sense? Thanks in advance.
The kWh used values come from the infotainment screen. My calculations estimate the capacity between 58 - 62 kWh with the battery temp in the mid 50s F. If 70 F yields the highest capacity, and according to Sean's FAQ the capacity drops about 1% per 2 F below 70 F, I need to add about 7% to get the capacity under ideal conditions. Assuming the kWh at 10% SoC is more accurate, then the capacity should be around 62 kWh (58 kWh X 1.07%). Does this all make sense? Thanks in advance.
1 - 20 of 46 Posts
What was the average m/kWh or kWh/100 km in both cases : 50% and 10% ?
I didn't check my m/kWh. My driving was atypical - highway speeds with the cabin heat turned on in order to run down the battery faster. How would it help to record my m/kWh? I could run the test again over the next week or so driving as I normally do and record it if I know how to use it. Thanks
How would it help to record my m/kWh?
If you discharge a battery at 1/10C, you can actually get more energy out of it than if you discharge it at 10C, because some energy is lost to heat at higher C rates. But unless one test was done at 25 mph average, and the other was done at 93 mph average that isn't going to account for the difference you are seeing. The difference is caused by greater accuracy the larger the sample size. If you ran out 100% of the battery, you capacity test would be 100% accurate.
Yup. Can't wait for warm weather.Assuming the kWh at 10% SoC is more accurate, then the capacity should be around 62 kWh (58 kWh X 1.07%). Does this all make sense?
Wait! Why are you using the Raw HD SoC to calculate usable capacity? As far as I know, everybody has used the DIC SoC to do these calculations.I got a new battery in my 2017 Bolt 4 days ago and did my first capacity check using OBD-2 codes from Sean Graham (thank you Sean).
I used SoC Raw because that's the only OBD name I've seen referred to in this context, and that was only one time. Most instructions I've seen say to "use OBD". Using DIC instead of SoC Raw the capacity value is 55.5 kWh.
In another discussion I saw people refer to the Ah measure called Bat Cap Raw as accurate and as something GM uses for the battery warranty. If that's true, my fully charged new (nominal 64 kWh) battery has (161 Ah X 398 V)/1000 = 64.1 kWh. However, by that measurement my old battery (nominal 60 kWh) had 65.5 kWh, which is hard to believe.
Suffice it to say, I'm confused.
In another discussion I saw people refer to the Ah measure called Bat Cap Raw as accurate and as something GM uses for the battery warranty. If that's true, my fully charged new (nominal 64 kWh) battery has (161 Ah X 398 V)/1000 = 64.1 kWh. However, by that measurement my old battery (nominal 60 kWh) had 65.5 kWh, which is hard to believe.
Suffice it to say, I'm confused.
Trying to reduce your confusion: DIC SOC is an OBD value. It gets used because it actually gets to 100%, whereas the raw value is not at 100% when you have charged the battery to its maximum. Driving a full battery to less than 10% (ideally as close to zero as possible) is used because the battery is not linear. Ah capacity is probably a better measure, but multiplying that by an average voltage won’t be totally accurate either. Finally, both Ah and kWh capacity fluctuate over time and with temperature. My Ah (2020) has ranged from 183 to 189, and is currently at 187.I used SoC Raw because that's the only OBD name I've seen referred to in this context, and that was only one time. Most instructions I've seen say to "use OBD". Using DIC instead of SoC Raw the capacity value is 55.5 kWh.
In another discussion I saw people refer to the Ah measure called Bat Cap Raw as accurate and as something GM uses for the battery warranty. If that's true, my fully charged new (nominal 64 kWh) battery has (161 Ah X 398 V)/1000 = 64.1 kWh. However, by that measurement my old battery (nominal 60 kWh) had 65.5 kWh, which is hard to believe.
Suffice it to say, I'm confused.
Good to know. That would put the new battery estimated capacity at 56.35 kWh. Thanks.
I hope this doesn't further muddy the waters: Sean also provided us with pids for estimated kWh capacity, although he admitted they are rather conservative. I modified the formula for mine to closer match my run down calculation just to have a quick reference. By sheer happenstance I exchanged a few emails with him shortly before he dropped off the various Bolt forums, during which he shared the updated formula he was then using, which happens to produce a result almost identical to mine. I'm not sure how well the modifications transfer from the 2019+ formula to the 2017-2018 version though.Trying to reduce your confusion: DIC SOC is an OBD value. It gets used because it actually gets to 100%, whereas the raw value is not at 100% when you have charged the battery to its maximum. Driving a full battery to less than 10% (ideally as close to zero as possible) is used because the battery is not linear. Ah capacity is probably a better measure, but multiplying that by an average voltage won’t be totally accurate either. Finally, both Ah and kWh capacity fluctuate over time and with temperature. My Ah (2020) has ranged from 183 to 189, and is currently at 187.
Yeah. As I recall his last formula for the 2017-2018 amounted to Ah x 320.0 volts . Mine is Ah x 332.5 volts. Wesley's was Ah x 319.68 volts. All were based on our own capacity runs.I hope this doesn't further muddy the waters: Sean also provided us with pids for estimated kWh capacity, although he admitted they are rather conservative. I modified the formula for mine to closer match my run down calculation just to have a quick reference.
Your numbers both muddy the waters and raise a concern. Your Ah measures are in the 180s, while mine are 167 for the old battery and 161 for the new battery. Is my battery temperature (56 F) cold enough to explain that decreased capacity? I doubt it, but I don't know. Or does your newer model Bolt have a more accurate way to measure capacity? It would be useful if forum members who have OBD readers and newer 64 kWh batteries (original or replacement) could post their Ah and temp values. Even a handful would give us some idea of what's normal.
I think the bottom line here is none of this is an exact science. I’ve seen #s from 3 new batteries lately: 2 @ 194.3, and 1 @ 202 🤷🏻♂️ FWIW, my 187 is at 20°F, and fluctuations seem to occur over relatively long periods of time. I also don’t know if those folks using EngineLink achieve the same results as Torque (although they should if they’re using the same pid.Your numbers both muddy the waters and raise a concern. Your Ah measures are in the 180s, while mine are 167 for the old battery and 161 for the new battery. Is my battery temperature (56 F) cold enough to explain that decreased capacity? I doubt it, but I don't know. Or does your newer model Bolt have a more accurate way to measure capacity? It would be useful if forum members who have OBD readers and newer 64 kWh batteries (original or replacement) could post their Ah and temp values. Even a handful would give us some idea of what's normal.
There was a big range of Ah, when new, for 2017-2018 batteries, ranging from 185 Ah to our 167.7 Ah, and probably some lower that never saw an OBD 2 check.I think the bottom line here is none of this is an exact science. I’ve seen #s from 3 new batteries lately: 2 @ 194.3, and 1 @ 202 🤷🏻♂️ FWIW, my 187 is at 20°F, and fluctuations seem to occur over relatively long periods of time. I also don’t know if those folks using EngineLink achieve the same results as Torque (although they should if they’re using the same pid.
From June of 2018 to June of 2019, the first full year I had Torque Pro, our Ah went from 167.7 Ah to 180.0 Ah, and everything in between.
The Bolt technician at our local dealer has agreed to put my car on his OBD reader, which is amazing given the pressure on him to swap batteries. I'll ask him to check Ah capacity. It's possible my EngineLink measure isn't accurate for some reason, or maybe he has a different way to measure capacity that I'm not seeing in Sean Graham's spreadsheet of OBDs.
Thanks Voltar, Gjetson, and Toyotiac for your help! If you think of anything else, please let me know. This concern about capacity, unfortunately, takes a bit of the shine off having a new battery. After getting on official record of the capacity from the dealer, I'll just live with the battery and see how it behaves instead of fussing over it.
Thanks Voltar, Gjetson, and Toyotiac for your help! If you think of anything else, please let me know. This concern about capacity, unfortunately, takes a bit of the shine off having a new battery. After getting on official record of the capacity from the dealer, I'll just live with the battery and see how it behaves instead of fussing over it.
...for that cycle. Other cycles may vary. Change is the only constant.The difference is caused by greater accuracy the larger the sample size. If you ran out 100% of the battery, you capacity test would be 100% accurate.
And the long term trend is down, always and forever, with all batteries....for that cycle. Other cycles may vary. Change is the only constant.
I will say this : you’ll get different readings every time you do them. If you want to know what’s exactly your available battery, drive your Bolt from 100% to 0%.The Bolt technician at our local dealer has agreed to put my car on his OBD reader, which is amazing given the pressure on him to swap batteries. I'll ask him to check Ah capacity. It's possible my EngineLink measure isn't accurate for some reason, or maybe he has a different way to measure capacity that I'm not seeing in Sean Graham's spreadsheet of OBDs.
Thanks Voltar, Gjetson, and Toyotiac for your help! If you think of anything else, please let me know. This concern about capacity, unfortunately, takes a bit of the shine off having a new battery. After getting on official record of the capacity from the dealer, I'll just live with the battery and see how it behaves instead of fussing over it.
Do what this guy did here
My new battery has a sticker on it that says 64kwh. That's all I need, really.
I did math also based on the car displays and it comes out very close to 64. Acceptable because of lack of significant figures, unsure of rounding vs truncation in the car display as well.
I did math also based on the car displays and it comes out very close to 64. Acceptable because of lack of significant figures, unsure of rounding vs truncation in the car display as well.
1 - 20 of 46 Posts
- This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Chevy Bolt EV Forum
We’re the Largest Chevy Bolt EV Online Community and Owner's Club. Join to discuss sport mode, reviews, battery range and charging!
Full Forum Listing
Recommended Communities
