🔋 Baseline for HV Battery SoH Performance (Battery Degradation Data by Taycan Owners)

[Scandinavian]

Just a question here. In the CarScanner app there is one measure in several pages I think, that shows the remaining kWh in the battery.

Do we have any information about how Accurate this is. I looked at the screenshot I showed in an earlier post and at 73% charge level it seemed to indicate only 43 kWh. Which would calculate to a 100% level of only holding less than 60 kWh fully charged? I know that you can get a fairly accurate measurement of capacity in other EV’s but no idea what Taycan shows?

Has anybody looked at this and would it be worth to follow that statistic as well??

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[ciaranob]

Just a question here. In the CarScanner app there is one measure in several pages I think, that shows the remaining kWh in the battery.

Do we have any information about how Accurate this is. I looked at the screenshot I showed in an earlier post and at 73% charge level it seemed to indicate only 43 kWh. Which would calculate to a 100% level of only holding less than 60 kWh fully charged? I know that you can get a fairly accurate measurement of capacity in other EV’s but no idea what Taycan shows?

Has anybody looked at this and would it be worth to follow that statistic as well??

Will def look later - busy - seem to recall off values here but will follow up as indeed could be very useful.

 

[ciaranob]

Just a question here. In the CarScanner app there is one measure in several pages I think, that shows the remaining kWh in the battery.

Do we have any information about how Accurate this is. I looked at the screenshot I showed in an earlier post and at 73% charge level it seemed to indicate only 43 kWh. Which would calculate to a 100% level of only holding less than 60 kWh fully charged? I know that you can get a fairly accurate measurement of capacity in other EV’s but no idea what Taycan shows?

Has anybody looked at this and would it be worth to follow that statistic as well??

Meant to ask - what was the GOM range prediction when you took that reading - if the battery at 73% SoC really only had 44 kWh then presumably the predicted PCM range must have been 20% lower than normal I.e. was this when your ranges plummeted?

 

[Scandinavian]

Meant to ask - what was the GOM range prediction when you took that reading - if the battery at 73% SoC really only had 44 kWh then presumably the predicted PCM range must have been 20% lower than normal I.e. was this when your ranges plummeted?

Yes that was part of it. I did take a photo then and GOM said 215 km. But that range dropped very fast at that stage

 

[ciaranob]

Yes that was part of it. I did take a photo then and GOM said 215 km. But that range dropped very fast at that stage

OK - quick update and the answer is yes!

Note: as per comments in my introductory Post #1 i this thread:

The PB+ should have available ca. 83 kWh (Porsche’s public posting) - in reality it has been shown to be closer to 86kWh available (I’m rounding numbers here).

So for my car CarScanner currently reporting 88% SoH:

88% of 83kWh = 73 kWh available

88% of 86kWh = 75.7 kWh available - most probable value.


My car’s current readings (car dash and CarScanner app):

SOC = 44.5

CarScanner ‘Battery Energy’ = 33.8 kWh

This gives a calculated 100% ‘Battery Energy’ = 33.8/.445 = 75.95 kWh


This is an almost exact match to my current SoH calculated available battery capacity, so it would seem to validate the ‘Battery Energy’ number reported in the CarScanner app.

So again, answer is yes, most definitely seems to be a decently accurate representation of your current usable battery capacity

PS: My GoM range predictions seem to be AOK i.e. with AC off and at SoC of 44.5% - in Normal mode I am seeing 116 miles and in Range mode 120 miles - thus at 100% these would be 260-270 miles range which is on par with expected (albeit lower than last year but another discussion and I think directly related to my SoH drop).

 

[ciaranob]

Just a note to follow up on last post - I am seeing a ca. 7% drop in predicted ranges for Sep 2023 vs Sep 2022 (tracked every charge and consumptive data since ownership).

Now of course there are multiple variables here but it is WAY more than coincidence that my SoH has dropped from 93% to 88% in the exact same time interval - a 5% drop. The lack of long distance trips and excessive heat in 2023 vs 2022 etc can easily account for the additional 2% difference.

All in all the SoH and Battery Energy values from CarScanner for my car seem to match very well the recorded change in GoM ranges (averaged over multiple readings) and can most probably be almost directly related to the drop in SoH.

 

[ciaranob]

My SA has agreed to a complimentary PIWIS SoH test on my next service visit which is Sep 11th - very interested to see what readouts we get! Continued great customer service from Porsche North.

 

[Bognar67]

Just a question here. In the CarScanner app there is one measure in several pages I think, that shows the remaining kWh in the battery.

Do we have any information about how Accurate this is. I looked at the screenshot I showed in an earlier post and at 73% charge level it seemed to indicate only 43 kWh. Which would calculate to a 100% level of only holding less than 60 kWh fully charged? I know that you can get a fairly accurate measurement of capacity in other EV’s but no idea what Taycan shows?

Has anybody looked at this and would it be worth to follow that statistic as well??

According to my last reading (Real SOC=50,98%/SOH=93,09%/Battery Energy=40kWh) it seems more or less accurate although next to 50,98% SOC and 40kWh Energy the SoH should be 93,7% against the displayed 93,09%. Assuming the 83,7kWh official net battery capacity.

 

[ciaranob]

According to my last reading (Real SOC=50,98%/SOH=93,09%/Battery Energy=40kWh) it seems more or less accurate although next to 50,98% SOC and 40kWh Energy the SoH should be 93,7% against the displayed 93,09%. Assuming the official 83,7kWh official net battery capacity.

OK, so the 83.7kWh 'published' usable is almost definitely under-reported as others have essentially proved (see Post #1) - actual is in fact thought to be 86.7 kWh of usable capacity of the PB+.

So, looking at your OBDII readout above:

Battery Energy = 40
SoC = 49.7
Soh = 93

So 93% (SoH) of usable 86.7 kWh = 80.6 kWh available to you in you car with your current Soh.

Your 'Battery Energy' at 40 kWh with an SoC of 49.7% provides a calculated estimate of usable kWh of 40/.497 = 80.5 kWh

I'd say that is pretty darn consistent !

PS: I'd have to check back as honestly can't recall right now but isn't the SoC HR a higher value than actual SoC - hence why I used the 49.7 from you readout?

UPDATE: Just to confirm that indeed the CarScanner's "SoC Display" field matches the PCM dash SoC values whilst the app's "SoC HR" field has a higher value than the PCM dash.

 

[ciaranob]

Chart is in Post #1 but thought I'd repost here as I mentioned it in a couple of priors in that as of this month (Sep 2023) I have yet to see the impressive GoM max. ranges (AC off) I was seeing my first year - Soh plotted on top - again I suspect this apparent range drop in part due to 3 months of excessive heat wear on the battery here in Texas and a lack of long distance trips (also a lot of travel abroad with car sitting stored) - essentially I'm seeing a 10% drop in 'predicted' GoM max. ranges (again not actual consumptive but at an least apples to apples comparison).

Don't believe that it is mere coincidence that my total SoH drop from new is 12%. Hoping for this cursed heat to relax somewhat in the next two months here and we'll see with a few long trips added if I can revive longer range estimates.

 

[2P168S]

Data update from me:

SoH shows as 89.41% at 19,900 miles. There was a bit of fast charging since my last update but mostly AC charging.

Not sure if you are thinking about in terms of cycles, but I estimate based on mileage and efficiency that the battery has seen approximately 13 equivalent cycles since my previous update, where my SoH was 92.33%

 

[ciaranob]

Data update from me:

SoH shows as 89.41% at 19,900 miles. There was a bit of fast charging since my last update but mostly AC charging.

Not sure if you are thinking about in terms of cycles, but I estimate based on mileage and efficiency that the battery has seen approximately 13 equivalent cycles since my previous update, where my SoH was 92.33%

Thx - will update chart later - cycles highly relevant indeed but (and correct me if wrong), typically refer to ‘full’ 0-100 charge-use cycles in respect any no. of such cycles a battery is designed to operate through I.e. if not this then not an easy metric to define for all users and capture. I need to think about this some more!

 

[2P168S]

Thx - will update chart later - cycles highly relevant indeed but (and correct me if wrong), typically refer to ‘full’ 0-100 charge-use cycles in respect any no. of such cycles a battery is designed to operate through I.e. if not this then not an easy metric to define for all users and capture. I need to think about this some more!

It's common practice (in my non-EV but highly battery related industry) to use "equivalent full cycles" as a figure of merit. Essentially, energy throughput divided by nominal energy capacity. To calculate this, you'd need lifetime efficiency averages from users as well as mileage.

 

[ciaranob]

It's common practice (in my non-EV but highly battery related industry) to use "equivalent full cycles" as a figure of merit. Essentially, energy throughput divided by nominal energy capacity. To calculate this, you'd need lifetime efficiency averages from users as well as mileage.

Ah - thx - that’s interesting, so an equivalent measure is used despite say ‘actual’ cycling or ‘wear’ bring different for the use history of separate component modules etc.?

We can def extract total energy through put - will play with that a bit!

 

[2P168S]

Ah - thx - that’s interesting, so an equivalent measure is used despite say ‘actual’ cycling or ‘wear’ bring different for the use history of separate component modules etc.?

We can def extract total energy through put - will play with that a bit!

Correct, two batteries with the same "equivalent full cycles" may have different usage profile histories. But because energy throughput is such a significant predictor of degradation, it's still useful.

Because so many of the vehicles in your data set likely have similar efficiencies, the accuracy gains from doing it this way vs mileage may be limited, but it should still be slightly more insightful because it is closer to what is ultimately driving the degradation in the battery.

By the way, love what you are doing with this! A ton of effort and very cool results.

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