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.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.
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.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.
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.Ah, well that sucks! They probably buried it in some other PID or it may even be on the other CAN bus.
I think people who are unfamiliar with CAN Bus messaging protocol would not be able to decipher this easily.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.
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.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.
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.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.
A response of 03 7F is definitely an invalid request message. The 7EC part is not relevant. Your message is not recognized. It is not a valid request. 03 7F is essentially The same as Syntax Error or asking for something out of range.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.
No, I believe that it's almost 100% accurate for the current conditions.Our 12/16 build Bolt LT now has over 24K miles on it.
I first got the app set up 06/17/18. It started at 57.7 kWh, and has moved as low as 56.2 kWh on 09/09/18 to as high as 60.0 on 04/09/19. It currently is 58 kWh and change.
At this point I would say, however it is measuring, it is only within +/- 4% accuracy. The only number that really matters is the usable capacity. This can only be determined, with precision, by running from 100% to as far below 5% as you are prepared to go.
We are seeing very little degradation - on the order of 5-8% after 100,000 miles.Hello everyone, I just bought a used Bolt the other day (a Nov '16 build) with 101k miles on it. Just ran it from 100% down to "low power" (it stopped indicating range once I dropped below 20mi estimated left, maybe this was because I "dropped the hammer" coming up to my house and sent it into "low power", idk yet the behavior of these vehicles when you get them that far down) so I decided to just calculate it.
That last 20mi @4.3mi/kWh the efficiency I was getting came out to 4.65kWh (at the time I couldn't get a trusted SoC result so I decided to calculate it using the 4.3 mi/kWh I had been getting up until that point.
With my energy summary reporting 53kWh used I figured that particular charge would have resulted in a 57.65 usable kWh.
Shortly after this I hooked up my freshly acquired Chinese Elm327 OBDii Reader and manually inputted some tester Pid's and using the "Divide by 30" method got a "battery capacity" figure of 57kWh even.
Can anyone chime in on how I might be doing this wrong or if I should consider other factors when making this assumption? I feel 57kWh (or 57.65 by my estimate) is a little high for a Bolt this old or high mileage.
I'll be taking many many more logs once I can figure out how to transfer those CSV files (for now I have to literally enter them in one by one with each equation. I'll also run the "multiply by 0.35 or 0.30" versions and see what I get from them)
Also as a side note, even though the car is new to me, I can confirm it was an ex Uber Lyft vehicle and has only had one owner, so its safe to assume this car has seen a hard life. I also plan to use this vehicle as moreorless a work truck/commuter. So many many more miles and DC fast charges to come.