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Discussion Starter · #1 · (Edited)
Reading the German forums I found they made a shared Battery state of health (SoH) tracking spreadsheet to see how the batteries are doing over time. Some of us have already been doing this, so I translated and made it into one we can use in the US to both track our own battery, and compare to everyone else who wants to contribute their numbers. To use this to track and graph just your own battery SOH use File-Download to get your own copy of this spreadsheet and use Excel or other spreadsheet app (I use the free Apache OpenOffice.) and then you can delete all the other data in your downloaded copy to track just your car.


To add your data to this shared sheet in my google docs, go down to the end and add your data. Please don't modify anything like sort, filter, or other people's data since any change you do shows up for everyone. It doesn't need to be in any special order for the graphs to be useful. Download your own local copy if you want to play with sort, filter, etc. To see the graph of the data use the SoH vs Miles tab at the bottom.

Here is how to get an accurate SoH number. You need an OBD dongle and the car scanner app (android or iOS.)
Discharge to <10% and charge to > 90%, then wait an hour for the BMS to balance the cells. Temperature around 70F. Then read the Maximum energy content of the traction battery, and both the battery and outside temp. If your battery is not near 70F the number may be lower by 1-2kwh and this is why its good to note that in your tracking. The battery temp is the one that matters, and its useful to record the outside temp so people realize there can be a big difference between the battery and outdoor temp.

All our ID.4 so far are 77kWH when new, and when the smaller battery models arrive they will be 58kWH. The spreadsheet automatically calculates your SoH in column I and L from your inputs. The ratio of AC/DC kWH may be useful once we get enough data here to see if that makes much difference in SoH. This Ratio is in % so the numbers should add to 100 such as 90/10 means 90% AC, 10% DCFC.

Please don't enter your data more than once a month or it will skew the graphs compared to other people's data. Here is the current graph from the German forum with 53 data points:
Rectangle Slope Plot Font Parallel

and here is the German shared spreadsheet this started from, and its in KM so best to not add our US data to it (don't mess it up!)

Here are 2 more big threads with many numbers and discussion so the knowledge is linked together, and you can compare:

I will add the US graph to this post once we get enough data for it to be interesting. I know some of you here have been tracking this data!
 

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Discussion Starter · #3 · (Edited)
Here are dongles that are proven to work for this with car scanner (search your app store) :
I have used this $22 one for the past 6 years on multiple cars (android only.) Watch out some of the other cheap BT dongles have many problems.
BAFX Products - Bluetooth OBD2 OBDII Car Diagnostic Code Reader Scanner Tool
for iOS there are less choices since they need the expensive Apple authentication chip, these should work on iOS or android:
$140 OBDLink MX+
$32 but slow because its BLE: Veepeak OBDCheck BLE (this one has no security so don't leave it plugged in.)
 

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I've used this dongle with an iPhone 13 without issue.
for iOS there are less choices since they need the expensive Apple authentication chip
You know this topic much better than I do, and I get there are reasons to use the more expensive products, but I'm using a cheaper BLE dongle with CarScanner on my iPhone 13 with no issues I can detect. The dongle also works for ABRP integration. I don't leave it plugged in when I'm not in the car.
 

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Discussion Starter · #5 ·
I've used this dongle with an iPhone 13 without issue.

You know this topic much better than I do, and I get there are reasons to use the more expensive products, but I'm using a cheaper BLE dongle with CarScanner on my iPhone 13 with no issues I can detect. The dongle also works for ABRP integration. I don't leave it plugged in when I'm not in the car.
Which dongle? Link to it here since others may want to use it. Some BLE dongles will work but with a 100x slower data rate, so you may not be able to monitor as many parameters at the same time, or in real time. This slowness is no problem for checking the battery SoH since you don't need real time fast updating like you get with BT classic dongles. BLE does not need the Apple auth chip so they are a cheaper option, but I can't tell you which ones will work since I quit writing apps for iOS a few years ago.
 

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Here is how to get an accurate SoH number. You need an OBD dongle and the car scanner app (android or iOS.)
Discharge to <10% and charge to > 90%, then wait an hour for the BMS to balance the cells. Temperature around 70F. Then read the Maximum energy content of the traction battery, and both the battery and outside temp.
Do we know that 10-90% is the correct range for this test? Is that in the owners manual? Sorry I can't look it up myself, I don't have one yet.
 

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Discussion Starter · #9 ·
Do we know that 10-90% is the correct range for this test? Is that in the owners manual? Sorry I can't look it up myself, I don't have one yet.
You can read the Max. energy content without doing this. Doing a deep cycle helps the BMS learn the capacity to report more accurately, but the battery temp is the biggest thing that causes the number to vary. This procedure comes from the VW shop battery test procedure posted here in multiple places.
 

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Discussion Starter · #10 ·
Lol OK I'll add mine in 7 months
Note this is battery temp, and in winter your battery is heated while driving, and heated even more while charging, especially DCFC. So there are times even in cold weather when you could get the battery to 70F. Even if you don't hit 70F its worth checking and logging the SoH, and once we get enough data you can see how much the temp variation changes it. Its more a problem in hot areas, because the battery is not cooled to anything near 70F so in this case you might need to wait overnight for it to cool after driving or charging to get a more accurate reading.
 

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while on this topic of OBD, perhaps SunWizard could make a list of recommended android and ios apps to be used, as well as the OBD devices? would really help those of us, myself included, who are just newbies in this topic.

thank you in advance.
 

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Discussion Starter · #12 ·
I listed the dongles I know work above in post #3. Car scanner is the only app needed for this, iOS or android, and its free.

There are many other apps but they are off topic for this thread. I think people said you can get this same data with OBDeleven but their dongle only works with their app and I have not used it so will not recommend it or comment.
 

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thank you SunWizard.

can one dongle and the app be used for multiple cars in the household?
 

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Discussion Starter · #14 ·
thank you SunWizard.

can one dongle and the app be used for multiple cars in the household?
Yes. But it would make any data you record with it be confusing. I like to record data and graph it later rather than try to watch it change while driving.

I bought and recommend this mount and switch made by a forum member @mochalatte to turn the OBD dongle off when not in use since it can keep the car powered up and consume a little of the HV battery. You can also remove and re-insert the dongle each time, so its value depends on how often you use the OBD. I use it often since it shows all kinds of interesting info about the car that I have been posting in many threads here.
 

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Hoping someone can tell me if I am reading data wrong.

Charged at L2 today from ~28% to 80%. Curious of battery and 12V level after charging I plugged in my dongle to move my car from the charging spot. Car scanner was showing 53,925 watts with BMS reporting 78.4% state of charge, doing hand calcs on 77 KWH usable it seems the 80% number should have been closer to 60,000. Am I reading something wrong here? Temps were optimal at ~72-73 degrees F ambient and similar battery temps.
 

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Discussion Starter · #16 · (Edited)
Hoping someone can tell me if I am reading data wrong.

Charged at L2 today from ~28% to 80%. Curious of battery and 12V level after charging I plugged in my dongle to move my car from the charging spot. Car scanner was showing 53,925 watts with BMS reporting 78.4% state of charge, doing hand calcs on 77 KWH usable it seems the 80% number should have been closer to 60,000. Am I reading something wrong here? Temps were optimal at ~72-73 degrees F ambient and similar battery temps.
That number is always lower than 77kwh even when you charge to 100%. Some discuss it in this thread:
  • Maximum energy content of HV battery is bottom buffer + 0-100% display SOC, but not top buffer which is unusable, in Wh. It's 96% of full battery capacity
  • Energy content of HV battery is 0-100% display only, in Wh. It's 90% of full battery capacity when display says 100%
  • 0-100% display SOC is 6-96% BMS SOC
Its SOC is just a guess, and the SOC display is different from SOC BMS, and there are buffers on top and bottom. The thing that still makes the quoted explanation confusing is what about the 5kwh buffer between the 82kwh nominal and 77kwh usable capacity VW claims?
Since that is all too complex, ignore the Energy content, and only use the Max. energy content for SoH as described in post #1. With that you don't need any hand calcs since the BMS re-calibrates the calcs with every deep cycle, and a new car starts at 77kwh for it.
 

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Discussion Starter · #18 ·
I cannot locate AC vs DC charge history in Carscanner... can someone screenshot the page it's on?
I have never seen any charge history. 🤷‍♂️
I scroll through the All sensors where there are not pages, you have to know the exact wording of the parameter you want.
 

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Discussion Starter · #20 ·
I can be fairly accurate using EA app charge history
Yes me too, EA history is good for the DCFC but I had to manually write down a few EA where it was free-for-all and never made it into the history. Most of my charge is on my home Goplug which displays a running lifetime total kwh. Not to worry if your numbers are off (or even left blank like temperatures) since that is only for looking back and seeing if there is a pattern of those who do much more DCFC are having more degradation. The temp. is mostly useful since I have observed a huge drop in the Max. energy content as the battery temp goes down (drops around 1000wh in a few days), which skews my numbers in winter.
 
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