And is the figure in the app correct? Or are they all wrong? There's also the figure reported in the log on the car, does that match the trip computer? Lots of questions to investigate I guess! :)
Thanks for the analysis. One thing to question, is the energy remaining figure you're getting from the scanner accurate? I've been doing some tests and what I noticed is that number is not consistent with the SoC reading. Whether you use 77400 Wh or 74000 Wh as the 100% SoC, the energy remaining number is always quite a bit less. I've been trying to get a handle on this but haven't gotten enough data points to understand it. If you have any insight it would be great to hear. Also, go back to your spreadsheet and use the various SoC numbers against the full 77400 Wh bank, does it change any of your calculations?
Yes, I've noticed a lack of linearity too. Easy to spot at 50% SOC when it's obvious that the value seen is not 1/2 of the 100% SOC value. I'm still convinced the incorrect efficiency readout is regen related though.
I just did a 100% to 2.5% based SoC per my bluetooth dongle. It was on crawl mode and power was super limited on acceleration and speed. I was pushing it for sure and it was a learning lesson as I will not be doing that again. It's just not worth it. My efficiency was low around 2.3kWh vs my expected 3.0kWh. It was raining the whole time so I believe this was why. I have an EV6 GT btw. So when I charged to 89% according to Electrify America it showed that I was charged for 78.54kWh. Keep in mind that I couldn't charged more and if I did to 100% then it would've been a total of 88.25kWh. As you know the car is rated at 77.4kWh.
@@volcalstone one of the problems with looking at how much you fit into the battery from charging is that you need to know what the charging loss is and take that from the value. If you put 70 kWh in from the charge point and there's a 10% loss in the delivery then you've only put in 63 kWh. The only way for us to determine the charging loss is to compare the delivered amount (charger reading) to the received amount (battery remaining reading). But if you start to question the validity of the battery remaining value then you have to question the loss calculation too, then you're in a viscous circle of not knowing what's true and what isn't.
The SoC the car displays is conservative. When the car is charged to full where it stops, it shows 100% which may be obvious but if you read the OBD you’ll see a lower number (in my car 96.5%, this varies with battery health) because the car stops before it’s really full to protect the battery. Similarly (with opposite sign) the car displays a lower SoC than the real number at low SoC (I recently had my car to 5% displayed and BMS said 9%). Some people say there’s even a further buffer below zero, I am not going to test that. The SoC is also always rounded down to a whole number. That’s why when you have charged to 80%, it will almost immediately go to 79% as soon as you start driving.
@@tomm5936 from the research I've done I believe that the buffer below zero that can be accessed (if necessary) is 3 kWh. This would make sense with the battery being 77 usable kWh but the remaining energy above 0 being 74 kWh when new. The missing 3 is below zero. But I haven't tested that! :)
Hi I don’t think that you took into consideration the recuperation rate of your drivers style. If you factor that in you’ll find the data showed on the car is correct.
I don't think that's the case. I did a drive with the regen turned off and still found that the data didn't make sense. I will be looking into it further though.
That may help understand what the car calculates but I would agree with the video that the calculation should be (kWh in battery at the start - at the end) / miles driven.
That's really interesting, and well done. But this video could have been about 6 minutes long not half an hour! Soooo much fast-forwarding to get to the bloody point.
Fair enough, it did end up longer than I'd expected. But if I take stuff out then those who want to watch those parts can't, whereas if I leave it in those who don't want to watch it all do have the option of skipping.
It will be different in the app if you have a look mine is
And is the figure in the app correct? Or are they all wrong? There's also the figure reported in the log on the car, does that match the trip computer? Lots of questions to investigate I guess! :)
Thanks for the analysis. One thing to question, is the energy remaining figure you're getting from the scanner accurate? I've been doing some tests and what I noticed is that number is not consistent with the SoC reading. Whether you use 77400 Wh or 74000 Wh as the 100% SoC, the energy remaining number is always quite a bit less. I've been trying to get a handle on this but haven't gotten enough data points to understand it. If you have any insight it would be great to hear. Also, go back to your spreadsheet and use the various SoC numbers against the full 77400 Wh bank, does it change any of your calculations?
Yes, I've noticed a lack of linearity too. Easy to spot at 50% SOC when it's obvious that the value seen is not 1/2 of the 100% SOC value. I'm still convinced the incorrect efficiency readout is regen related though.
I just did a 100% to 2.5% based SoC per my bluetooth dongle. It was on crawl mode and power was super limited on acceleration and speed. I was pushing it for sure and it was a learning lesson as I will not be doing that again. It's just not worth it. My efficiency was low around 2.3kWh vs my expected 3.0kWh. It was raining the whole time so I believe this was why. I have an EV6 GT btw. So when I charged to 89% according to Electrify America it showed that I was charged for 78.54kWh. Keep in mind that I couldn't charged more and if I did to 100% then it would've been a total of 88.25kWh. As you know the car is rated at 77.4kWh.
@@volcalstone one of the problems with looking at how much you fit into the battery from charging is that you need to know what the charging loss is and take that from the value. If you put 70 kWh in from the charge point and there's a 10% loss in the delivery then you've only put in 63 kWh. The only way for us to determine the charging loss is to compare the delivered amount (charger reading) to the received amount (battery remaining reading). But if you start to question the validity of the battery remaining value then you have to question the loss calculation too, then you're in a viscous circle of not knowing what's true and what isn't.
The SoC the car displays is conservative. When the car is charged to full where it stops, it shows 100% which may be obvious but if you read the OBD you’ll see a lower number (in my car 96.5%, this varies with battery health) because the car stops before it’s really full to protect the battery. Similarly (with opposite sign) the car displays a lower SoC than the real number at low SoC (I recently had my car to 5% displayed and BMS said 9%). Some people say there’s even a further buffer below zero, I am not going to test that. The SoC is also always rounded down to a whole number. That’s why when you have charged to 80%, it will almost immediately go to 79% as soon as you start driving.
@@tomm5936 from the research I've done I believe that the buffer below zero that can be accessed (if necessary) is 3 kWh. This would make sense with the battery being 77 usable kWh but the remaining energy above 0 being 74 kWh when new. The missing 3 is below zero. But I haven't tested that! :)
Hi I don’t think that you took into consideration the recuperation rate of your drivers style. If you factor that in you’ll find the data showed on the car is correct.
I don't think that's the case. I did a drive with the regen turned off and still found that the data didn't make sense. I will be looking into it further though.
That may help understand what the car calculates but I would agree with the video that the calculation should be (kWh in battery at the start - at the end) / miles driven.
That's really interesting, and well done. But this video could have been about 6 minutes long not half an hour! Soooo much fast-forwarding to get to the bloody point.
Fair enough, it did end up longer than I'd expected. But if I take stuff out then those who want to watch those parts can't, whereas if I leave it in those who don't want to watch it all do have the option of skipping.