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Discussion Starter · #1 ·
I'm trying to find the easiest way to get instantaneous charge rate (in kW) and charging session log information (time stamp & kWh) for my new ID.4. I see there's an app on the iOS App Store called "Car Scanner ELM OBD2" that includes the ID.4 in its latest version history. Version 1.79.8 says it has "new readings for Volkswagen ID.3, ID.4, Skoda Enyaq." Has anyone who already has a ODB2 BLE device tried that app to see if it provides charging information?

I'm thinking about getting a OBD2 device like the Veepeak Bluetooth 4.0, but I'm trying to avoid getting an Android device or anything else that would turn this into a hobby. I just want an easy way to log charging information. Unfortunately my Level 2 charger is a dumb charger, so I can't get kWh from it.

Thanks.
 

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I'll grab the app now and try it out tonight or tomorrow with my BT dongle. Looks promising!
 

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Ok, tested it for a few minutes. Lots of info available it looks like. I’ll dig into it later. Might snag the pro version - looks like it might be worth it.
 

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Discussion Starter · #4 ·
Thanks for checking it out! Lots of interesting data there. Interesting to see the battery temperature at 90 degF--I thought the temperature was supposed to be maintained at a constant 77 degF.

Yeah, let me know if you see anything that lets you see how many kWh you added with a charge. Hopefully, it will let you see the results of several charge sessions.
 

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The car was heat soaked in a hot parking lot prior, so that probably explains the battery temp.

I tried charging the car on a 48A EVSE but the app reports 28 kilowatts (impossible) AND 27 amps. Must be a bug that it isn’t interpreting the values from the onboard charger correctly. I believe it does have a total kWh field that can be selected, but I didn’t have that one on the dashboard yet.

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Discussion Starter · #6 ·
Actually, the 27 A is probably DC current at the 367 V DC of the battery after the car's charger, right? So that works out to 9.9 kW charge rate which might make sense if any energy is going into thermal management of the battery.

Very cool--I've seen enough to go ahead and order a OBD BLE device. Looks like I'll have something interesting to play with on iOS.

Here's hoping that the iOS/OBD2 options for EVs multiply in the coming months.
 

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Actually, the 27 A is probably DC current at the 367 V DC of the battery after the car's charger, right? So that works out to 9.9 kW charge rate which might make sense if any energy is going into thermal management of the battery.

Very cool--I've seen enough to go ahead and order a OBD BLE device. Looks like I'll have something interesting to play with on iOS.

Here's hoping that the iOS/OBD2 options for EVs multiply in the coming months.
Yeah, I guess it makes more sense if it's measuring it on the battery side and not the inlet side of the onboard charger. I don't believe the A/C compressor was running though, so there's still about 2000 watts unspoken for. From what I recall, there were around three different sensor readings I could select for charging speed, but none of them really made much sense.

There's definitely a lot to play around with though, and it will be worth picking up a dongle. I'm using a "TONWON" branded BLE 4.0 device I got a few years back to modify my Prius Prime settings with.
 

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Discussion Starter · #8 ·
My Veepeak BLE dongle arrived today so I got to play around with it a bit. Doesn't look like there is any kind of charging log information available. There is a "Total accumulated charge kWh", but that shows 0. Maybe it will show something meaningful next time I charge?

One quick question: The Veepeak manual says to unplug the dongle when not in use. Is that a CYA thing, or is there a good reason to unplug it? Will it actually make a dent in the 12V battery if I leave it connected all the time?
 

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My Tonwon dongle goes dark when I exit the car, so I don't think it's getting any 12V until the car is on. You should be good leaving it in. I did all week, so far. Even checked it this AM for any lights and it was pitch black down there until I sat down.
 

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Discussion Starter · #12 ·
Veepak stays on, draws power from a different rail.
Yeah, I was about to say that not only is my Veepeak still lit up, but sitting here in my office I can still get live readings from my car in the garage. So do Veepeak owners unplug the dongle to avoid drawing down the 12V battery? Or is it a small enough not to have to worry about it?
 

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Yeah, I was about to say that not only is my Veepeak still lit up, but sitting here in my office I can still get live readings from my car in the garage. So do Veepeak owners unplug the dongle to avoid drawing down the 12V battery? Or is it a small enough not to have to worry about it?
lets assume that thing eats 3 watt in power (think 1w is more realistic, but lets assume worse case).
That is 72WH per day. the 12V battery is what, at least 50 amp hour? so that is 12(volt)*50(AH)=600watt hour.
that means you can keep it plugged in for at least a week without driving before the 12v is empty.
 

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The car was heat soaked in a hot parking lot prior, so that probably explains the battery temp.

I tried charging the car on a 48A EVSE but the app reports 28 kilowatts (impossible) AND 27 amps. Must be a bug that it isn’t interpreting the values from the onboard charger correctly. I believe it does have a total kWh field that can be selected, but I didn’t have that one on the dashboard yet.

View attachment 4051
Hybrid HEV/EV battery parameters seem incorrect in Car Scanner, probably because Hybrid/EV battery voltage is falsely reported (over 1000 volts)

However DC battery sensors in Car Scanner shown in your earlier post report correct values: kW power, amperage and voltage, while driving or charging:
 

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lets assume that thing eats 3 watt in power (think 1w is more realistic, but lets assume worse case).
That is 72WH per day. the 12V battery is what, at least 50 amp hour? so that is 12(volt)*50(AH)=600watt hour.
that means you can keep it plugged in for at least a week without driving before the 12v is empty.
I suppose it isn't possible for a OBDII dongle to wake on demand? Perhaps using just enough power for its radio?
 

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OBD2 dongles may drain the aux battery because they might keep some electronic modules constantly awake or take longer time before all electronics goes to sleep.

I always disconnect it, there are too many complaints about flat 12v batteries on EV forums.
 

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Discussion Starter · #17 ·
Thought I would share what I've been doing with Car Scanner ELM OBD2 on my Veepeak OBD BLE device. First of all, let me point out that there are a couple of things about this that are unpleasant: 1) In order to log the data, you have to have the app running and viewing the sensor data you want to have logged. It's quite clunky since the app is designed for ICE cars and is a general-purpose OBD app. You can leave the app momentarily if you need to do something else with your iPhone, but one very quickly sees the benefit to using a second device for logging the data. And 2) depending on the device, it might be powered up all the time. If you aren't going to drive in a few days, you might find your 12V battery discharged if you forget to unplug the OBD dongle.

That said, it is cool to be able to get insight into inner workings of a charge session. It works fine to just view the log data within the iOS app itself. Below is what the DC Fast Charge Session looks like within the app. In my next post I'll show some charts after processing the data a bit in Excel.

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Discussion Starter · #18 ·
Below are the charts for a DC Fast Charge session and a Level 2 home charge session for comparison. The data log that the Car Scanner Pro app outputs is a sparse CSV file with several rows of data for each second. I had to do a bit of Excel manipulation to just get it into the form of a single record of data per second. The other manipulation is that I inverted the DC Power and DC Current signals to be positive.

Everything makes sense, but there are a few things that are not clear to me. There are 3 different SOC signals that come back from the OBD device, none of which match exactly with what the car displays. The difference was most notable when I filled up to 100% charge before beginning our road trip. When the charging finished, the OBD signal named "State of Charge BMS" reported 96% and the OBD signal named "State of Charge Display" reported 100.03%. However, at lower SOC value, the "State of Charge BMS" is closer to the value displayed on the infotainment display.

Also, the DC Power signal from the OBD is less than the power shown as being delivered by the EA charge station. When I first plugged in, the EA charge station was saying 127 kW while the OBD data maxed out at something less than 125 kW. It's not too surprising since that might represent losses between the charge station and the car's battery.

Anyway, here's the charts for what they're worth:

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Also, the DC Power signal from the OBD is less than the power shown as being delivered by the EA charge station. When I first plugged in, the EA charge station was saying 127 kW while the OBD data maxed out at something less than 125 kW. It's not too surprising since that might represent losses between the charge station and the car's battery.
This is normal, as the cooling can take up to 6KW on top of the battery charging. So the EA station will show upto 6KW more than what OBD reports.
 

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Discussion Starter · #20 ·
Tangentially related... Here's what a charge session looks like from the perspective of the Solar Edge app for our solar panels. We just got solar a couple of months ago and I oversized the system a bit in anticipation of getting an EV. We were well on our way to generating more electricity than we could use, and then we sprung the ID.4 on them. Our panels have been whining "not fair!" ever since :)

Yes, the car was still charging at midnight today until about 3 AM.

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