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Showing my ignorance here.

Can you make gauges based on a formula you input into torque pro? I want to take vehicle speed in mph divided by instantaneous KW to give me a "real time" miles per kWh gauge.

Thanks,

Keith
 

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Showing my ignorance here.

Can you make gauges based on a formula you input into torque pro? I want to take vehicle speed in mph divided by instantaneous KW to give me a "real time" miles per kWh gauge.

Thanks,

Keith
I don't use Torque Pro as I have an iPhone and use LELink app instead, but I don't see why this wouldn't be possible. LELink supports this and much of the gauges I put on my screen are calculations from multiple formulas.

I think the way to go about it is to create a custom entry that puts out the number with the formula you need. Many of the values in the Custom PID file are already like this, so you can easily add one yourself. Then have the gauge use this custom entry.
 

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I don't have an official OBD scanner tool, but I have worked with CAN and J1939 and have a PCAN-USB adapter that can receive/transmit any and all messages on a CAN bus using PCAN-View (freeware). I wired it up to the standard OBD II CAN pins, set it to 500kbps, and can see all the data on the 2019 Bolt's OBD II CAN bus. If there's anything specific anyone would like me to look for just let me know and I'll give it a shot. This will all be raw data unless someone knows how to code in Python and can create an app that does all the dirty work.

For starters, I tried sending the 7DF 02015B0000000000 message (SoC raw, according to Telek's PID spreadsheet) and received 7E8 03415BCAAAAAAAAA. This appears to be a correct response with the data being CA hex, which is 202 decimal. Multiply by 100 and divide by 255 and you get 79.2% which is the SoC reported by the myChevy app.

Any suggestions on what message to transmit for the battery capacity? I tried 7DF and 7E4 032241A3 but it returned nothing and a 7EC 037F2231 which appears to be a "did not recognize request" type of response.
 

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Any suggestions on what message to transmit for the battery capacity? I tried 7DF and 7E4 032241A3 but it returned nothing and a 7EC 037F2231 which appears to be a "did not recognize request" type of response.
I didn't understand a word of what you wrote, but I do know that the battery capacity PID, which Telek found, does not work in the 2019 Bolt...only 2017 and 2018.
 

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Ah, well that sucks! They probably buried it in some other PID or it may even be on the other CAN bus.

This screen shot of the PCAN-View application shows the raw data I was babbling about. The Torque app shows you a nice GUI but does this stuff in the background. These are just some of the OBD II messages on the CAN bus after pushing the start button with the car off.
27244
 

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Ah, well that sucks! They probably buried it in some other PID or it may even be on the other CAN bus.
Yeah. But after 15 months of watching that PID value move up and down from 56.2 to 60.0, and everything in between, and back again, I have decided it doesn't give me any information I can use.
 

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It's certainly not worthless data! It seems like the capacity should be easy to calculate, but getting an accurate value is not trivial.

If you were to put the car in a temperature chamber and record the capacity value from -20C to 65C (approximate operating range for Lithium cells) you would see it decrease substantially at lower temps (below about 0C) and to a lesser degree at higher temps (above around 50C). That's just how these batteries operate.

There's a lot of speculation about how the capacity number is calculated. The more accurate single cell battery gas gauge ICs use a combination of measurements (voltage, current, temperature) and predefined parameters (chemistry, capacity, impedance, and other data that comes from lots of manufacturer testing) to determine the capacity and state of charge. And that's just for a single cell. Don't forget that the battery is really 96 series banks of 3 cells in parallel, which doesn't make this calculation any easier.
 

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I don't have an official OBD scanner tool, but I have worked with CAN and J1939 and have a PCAN-USB adapter that can receive/transmit any and all messages on a CAN bus using PCAN-View (freeware). I wired it up to the standard OBD II CAN pins, set it to 500kbps, and can see all the data on the 2019 Bolt's OBD II CAN bus. If there's anything specific anyone would like me to look for just let me know and I'll give it a shot. This will all be raw data unless someone knows how to code in Python and can create an app that does all the dirty work.

For starters, I tried sending the 7DF 02015B0000000000 message (SoC raw, according to Telek's PID spreadsheet) and received 7E8 03415BCAAAAAAAAA. This appears to be a correct response with the data being CA hex, which is 202 decimal. Multiply by 100 and divide by 255 and you get 79.2% which is the SoC reported by the myChevy app.

Any suggestions on what message to transmit for the battery capacity? I tried 7DF and 7E4 032241A3 but it returned nothing and a 7EC 037F2231 which appears to be a "did not recognize request" type of response.
I think people who are unfamiliar with CAN Bus messaging protocol would not be able to decipher this easily.

The first part would be:

7DF = request message
7E8 = response message

The second part would be:

For "02015B0000000000"...

02 = how many bytes are going to follow in this message (02 means 2 bytes, 03 means 3, and so on)
015B = the "SoC Raw" PID (01 = Show Current Data, 5B = Hybrid battery pack remaining life)
The following digits are ignored and are meaningless.

For "03415BCAAAAAAAAA"...

03 = we're looking at 3 following bytes here
415B = response from the "SoC Raw" PID (40 "response" + 01 Show Current Data, 5B = Hybrid...)
CA = actual data in hexadecimal (=202 in decimal)

As in the original post, the formula for this PID is data * 100 / 255, so it's 202 * 100 / 255 = 79.2(%)

The battery capacity PID for 2017-2018 Bolts was 2241A3, so that's why the "7DF 032241A3" was attempted. Some searching suggests that a "7EC 037F2231" is some sort of "out of range" response, so the 2019 Bolt is refusing to provide any data on that PID.


Technobabbles aside, it all comes down to finding another PID that does provide the data we need. I'm not well versed in the intricacies of the CAN Bus and the OBD-II scanner output, so I'm not sure if a "brute force" approach to scan all the possible PID space is reasonable or feasible.
 

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It's certainly not worthless data! It seems like the capacity should be easy to calculate, but getting an accurate value is not trivial.

If you were to put the car in a temperature chamber and record the capacity value from -20C to 65C (approximate operating range for Lithium cells) you would see it decrease substantially at lower temps (below about 0C) and to a lesser degree at higher temps (above around 50C). That's just how these batteries operate.

There's a lot of speculation about how the capacity number is calculated. The more accurate single cell battery gas gauge ICs use a combination of measurements (voltage, current, temperature) and predefined parameters (chemistry, capacity, impedance, and other data that comes from lots of manufacturer testing) to determine the capacity and state of charge. And that's just for a single cell. Don't forget that the battery is really 96 series banks of 3 cells in parallel, which doesn't make this calculation any easier.
It is true and I fully agree that getting an accurate battery capacity is not trivial due to the multitude of factors involved. However, I think the thing that most people are interested in is what the car thinks it’s current battery capacity is. All that calculation is already done internally, and the result is being used as a basis to calculate and display various numbers related to battery. It’s just that GM decided to not expose the raw capacity number outright to the consumers, and only “leak” it via PID 2241A3 in 2017-2018 Bolts.

Based on my nearly 32,000km (20,000 miles) of driving and nearly daily logging of the data, I can pretty much confirm that the said PID is indeed the raw capacity value that correlates with the SoC.

27246


Notice that the blue line (value directly calculated from the PID) go along nicely with the numbers derived from both the displayed SoC and the raw SoC. I think a 2019 Bolt user could reasonably assess the battery capacity with careful logging like what I did, and if any of the values from the CAN Bus has a correlation to those, then it should be a good candidate for the new battery capacity PID.
 

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From driving day in and day out, for over two years, I know that our Bolt could deliver up to 58 kWh for the first six months. For the last year and a half it can deliver 55 kWh minimum to 56 kWh maximum. I don't need any more info than that. I am expecting/hoping the battery to stay at about this level for several years, before seeing another significant drop.
 

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From driving day in and day out, for over two years, I know that our Bolt could deliver up to 58 kWh for the first six months. For the last year and a half it can deliver 55 kWh minimum to 56 kWh maximum. I don't need any more info than that. I am expecting/hoping the battery to stay at about this level for several years, before seeing another significant drop.
Hmm... that's similar to what's happening with my Bolt, too, according to the graph. The first five months hovered around 58kWh, then slid down a bit and settled around 56kWh for the past half year or so.
 
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