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(aka Telek) 2017 LT
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Discussion Starter · #1 · (Edited)
At long last, here is my work in progress! Please only share the link and not the values directly. I would like to make this a collaborative effort to discover and learn more about the car. I have included some basic recommendations and directions on how to get started for both Apple and Android.

Feedback is welcome!

 

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At long last, here is my work in progress!
First, THANK YOU!

I had to tweak the CSV file to make it load in EngineLink (it wanted the columns arranged differently).

Can you tell us a bit more about how you went about getting these PIDs? A source? Detective work? Is there a good way to scan for possibly useful PIDs?

You asked people to send you their reading from the Battery Capacity output. Mine says 60.43 kWh. One thing I noticed was that in BlackBolt's post on pack capacity, the “Hybrid/EV Battery Pack Capacity” was in Amp Hours, not kWh, so I wonder if this is the same PID used there, or if there is another one somewhere.
 

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At long last, here is my work in progress! Please only share the link and not the values directly. I would like to make this a collaborative effort to discover and learn more about the car. I have included some basic recommendations and directions on how to get started for both Apple and Android.

Feedback is welcome!

Shortlink to google spreadsheet: http://bit.ly/ChevyBoltPIDs
Great work!

First, THANK YOU!

I had to tweak the CSV file to make it load in EngineLink (it wanted the columns arranged differently).

Can you tell us a bit more about how you went about getting these PIDs? A source? Detective work? Is there a good way to scan for possibly useful PIDs?

You asked people to send you their reading from the Battery Capacity output. Mine says 60.43 kWh. One thing I noticed was that in BlackBolt's post on pack capacity, the “Hybrid/EV Battery Pack Capacity” was in Amp Hours, not kWh, so I wonder if this is the same PID used there, or if there is another one somewhere.
By chance, was your Bolt fully charged when you got the 60.43 kWh reading?
 

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Very nice. Thank you all for working on this. I will be watching closely. Once it is all sorted out for us computer illiterates, I will be thrilled to plug 'n' play.
 

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(aka Telek) 2017 LT
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Discussion Starter · #7 · (Edited)
First, THANK YOU!

I had to tweak the CSV file to make it load in EngineLink (it wanted the columns arranged differently).

Can you tell us a bit more about how you went about getting these PIDs? A source? Detective work? Is there a good way to scan for possibly useful PIDs?

You asked people to send you their reading from the Battery Capacity output. Mine says 60.43 kWh. One thing I noticed was that in BlackBolt's post on pack capacity, the “Hybrid/EV Battery Pack Capacity” was in Amp Hours, not kWh, so I wonder if this is the same PID used there, or if there is another one somewhere.
You're welcome :)

What did you have to change to get EngineLink to work? I'll add another page and reorder the columns then.

I used a random custom app written by a guy I found on another forum. It's just a really simple android app. I'll see if he's willing to "advertise" it, or maybe post the code on github so that we can improve it.

****, I wish that I had seen BlackBolt's post earlier. Yes, it's almost certainly the same PID, but I question if it's Ah. I think that /30 to get kWh makes more sense, as it gives us almost exactly 60kWh for everyone so far. The reason that I'm skeptical is because using this as Ah would be too high for pack capacity, considering that we know it's a "57kWh" rated pack. I can believe that we can squeeze 60 out of it, but 64 is too high.

This is a topic of much debate over on the Facebook group!
 

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What did you have to change to get EngineLink to work? I'll add another page and reorder the columns then.
Here's their format. (Guesswork on my part, based on files they provide. I thought it was supposed to read Torque Pro files, but it didn't seem to work when I tried it.)

I used a random custom app written by a guy I found on another forum. It's just a really simple android app. I'll see if he's willing to "advertise" it, or maybe post the code on github so that we can improve it.
That's be great.

****, I wish that I had seen BlackBolt's post earlier. Yes, it's almost certainly the same PID, but I question if it's Ah. I think that /30 to get kWh makes more sense, as it gives us almost exactly 60kWh for everyone so far. The reason that I'm skeptical is because using this as Ah would be too high for pack capacity, considering that we know it's a "57kWh" rated pack. I can believe that we can squeeze 60 out of it, but 64 is too high.
See my post in the other thread!

This is a topic of much debate over on the Facebook group!
I wouldn't know. I don't do Facebook, never have. (I thought it'd only last as long as myspace before the next thing came along. I guess I was wrong about that, but still feel pretty good about not going down that rabbit hole.)
 

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BTW, in my GM_Volt.csv (that came with EngineLink), I have:

222429,HV Volts,0,400,V,(Signed(A)*256+b)/64,7e1


In your Bolt CSV, that's marked as an unknown, but as I recall, this has provided meaningful-looking voltage measurements, and this is how Inst Kpower is calculated for the Volt and seemed to work fine for my Bolt, specifically it's

,Inst. kPower,-100,100,kW,[HV Volts]*[HV Discharge Amps]/1000,0


Is there some reason you're not using this one?
 

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Especially great job on providing a help page for others to purchase readers, Telek!
 

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One other random piece of possibly useful info: I looked at the correlation between “State Of Charge HD Raw” and “Battery Level Displayed”. I found that

State Of Charge HD Raw ~= 9 + 7/8 * Battery Level Displayed

That means that when the displayed battery is 0%, SoC raw will be 9%, and when displayed battery is 100%, SoC raw will be 96.5%.

I don't know if this formula is fixed or evolves over time as the battery ages, but for now at least it seems like a way to calculate a more accurate version of the displayed battery.
 

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I've noticed after a full charge, the raw SOC% is 96.5
Couple of occasions it read 96.1%. today it read 96.5 on my 17k mile 2017 Bolt.
Cool. It's great when practice aligns with theory!

(I rarely charge to full, so I didn't have these numbers myself. I live at the top of a hill, so if I do charge to full, heading down the hill it's going to go “beyond full” with regen — this really happens, once I hit flat road I have to drive for a bit before “energy used” climbs above zero.)
 

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Air Temp 0, mode + pid should be 0146, not 0046. But that was an easy catch (if nobody beat me to it), as it is one of the standard PIDs ;-)

I have imported your list in Torque Pro and many things seem to be working well (But, how does one know? If we knew the values to compare with, we wouldn't need this list, would we? :nerd:) I am using an OBDLink MX Wifi adapter in Infrastructure mode. When driving, it connects to a hotspot setup by my phone. The phone hotspot uses the same SSID and password as my home network, so when parked on the driveway, the adapter automatically connects to my home network, and I can access the data from my living room. Very nice :D

What I have noticed is that, after turning off the car, the adapter stays active. Even after the car finishes charging. But it will give back "NO DATA" to any query I send. I am okay with getting back "NO DATA", but I am a bit concerned with the adapter staying active and potentially draining the 12 volt AUX battery. Any idea how long before the AUX battery will be so low that I can no longer start the car?

BTW: interesting to see that, as soon as I access data from the car via OnStar, the adapter starts returning data as well ... for a while, that is.
 

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During an AC charge session, I got this:



Left column:
- AC Amps, reported by car
- AC Voltage, reported by car
- AC Watts, calculated from the above
- AC Watts, reported by my EVSE (I call that my Ampera EVSE, as I have one for my Outlander as well)

Right column:
- DC Amps, reported by car
- DC Voltage, reported by car
- DC Watts, calculated from the above
- Instant Power, reported by car

So, if I am not mistaken, we can see what goes on before AND after the AC/DC converter, giving us an impression of efficiency (95-ish percent)

Interestingly enough, with the car switch off, Instant Power is not available. Checking source PIDs (volts and amps), neither turn out to be available. So, I turned on the car, and recorded the screen for a while:


Instant Power does show. It is all over the place, but not getting near CAC Power or even CDC Power. I believe it IS aligned with the DIC, though. I had seen that before. Others (in the Netherlands) reported that the DIC value was much closer to what they expected, taking into account the EVSE capacity.

For those of you that have looked at the video with sound, ironically enough it is the Dutch radio news. In the second part they are announcing Trumps plans to cancel tax plans regarding green vehicles, installed earlier by Obama.
 

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This PID:

MG Current ?,?MG A1,2224DF,(Signed(A)*256+B)/10,-600,600,A,7E1

Seems to give pretty much double the value of this PID:

HV Current,HV Amps,222414,(Signed(A)*256+B)/20,-200,500,A,7E1

Which seems not weird, looking at the divider.
 

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Discussion Starter · #18 ·
BTW, in my GM_Volt.csv (that came with EngineLink), I have:

222429,HV Volts,0,400,V,(Signed(A)*256+b)/64,7e1


In your Bolt CSV, that's marked as an unknown, but as I recall, this has provided meaningful-looking voltage measurements, and this is how Inst Kpower is calculated for the Volt and seemed to work fine for my Bolt, specifically it's

,Inst. kPower,-100,100,kW,[HV Volts]*[HV Discharge Amps]/1000,0


Is there some reason you're not using this one?
Yes, because it's not correct, it's a red herring. If you monitor over time, it does NOT track as a voltage does, and if you take away the calculation used to transfer to a voltage, it tracks with other non-voltage things much closer than it does a voltage.

It's possible that it's voltage applied to a particular system (maybe the motor AC inverter?) But it's not a voltage that we can use outside of that.

If you want, record raw values and graph over time to see what I mean.

From my notes:

===== the following are all spiky while driving, 22534 while charging (0x5806), close to that when not moving =====
222428 -
222429 - was HV Volts (V)
22242D -
222434 - big bumps while driving
22288A - seems almost entirely flat, has some small bumps during driving but nothing while charging
? could be torque applied or motor voltage??
 

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Discussion Starter · #19 · (Edited)
One other random piece of possibly useful info: I looked at the correlation between “State Of Charge HD Raw” and “Battery Level Displayed”. I found that

State Of Charge HD Raw ~= 9 + 7/8 * Battery Level Displayed

That means that when the displayed battery is 0%, SoC raw will be 9%, and when displayed battery is 100%, SoC raw will be 96.5%.

I don't know if this formula is fixed or evolves over time as the battery ages, but for now at least it seems like a way to calculate a more accurate version of the displayed battery.
Oh, I have been working VERY HARD on this one, and it's not as simple as that.

Long story short, no linear function works. Yes, you can get close with a linear function ( Displayed_HD = 1.086(RAW_SoC_HD) - 5.857 ) but it's off at the top and the bottom.

Here's what I mean:

Note that the values that I recorded manually by hand by watching the charger closely match this from my 100-to-0-to-100% experiment, and from another vehicle too. It's not a linear progression. If I cut off even the top and bottom 20%, it still doesn't come out a straight line.

The slightly polynomial function does very closely match, but it's still a little bit off at the top and bottom. This seems bonkers, but is the closest to the data that we can collect.

You'll notice in my "to fix" tab of the spreadsheet that I have been playing with this, but this data shown here is more accurate.
 

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Discussion Starter · #20 ·
I've noticed after a full charge, the raw SOC% is 96.5
Couple of occasions it read 96.1%. today it read 96.5 on my 17k mile 2017 Bolt.
Yes, I've found the same. DCFC stops around 95.3 to 96.1 for me, but if I push it with L2 I can get up to 96.5.
 
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