Baseline for HV Battery SoH Performance

[ciaranob]

NOTE: I WILL UPDATE THE CHART HERE AS MORE DATA IS ADDED VS CONSTANTLY REPOSTING BELOW.


These data to date from 86 cars with 198 readings whilst clearly not a statistically robust sum are interesting nonetheless and some trends developing - in particular the known slightly higher degradation of SoH in hot climates (my primary interest).

The SoH% is believed to be, for example if we just take the 'published press' values, a % of the usable 83.7kW of the Performance+ 93.4kW capacity battery.

However 'real world' consumptive tests (e.g. #2 and insight provided by @rs38 here #38 ) suggests that Porsche were being conservative and the actual 'usable' unbuffered kW are closer 86.7kW.

Note a relatively consistent hot to warm climate more degraded SoH numbers. Cold country SoH's appear to straddle hot/warm and cool climate trends but numbers not statistically significant as yet.

I have placed 'error' bars of +/- 2 percentage pts. for every reading - this should be considered more a measure of observed variance especially after battery 'balancing' is performed as reported by a number of forum members and myself. So more correctly it s representative of the Soh range at any given time about a mean Soh value -2% on the high end and a +/- 1% being perhaps more typical.

Finally thought I'd post these two useful video links on battery degradation and how to minimize it (first originally shared by @Scandinavian) on optimal charging strategies towards preserving Soh over time by Dr. Jahn of Dalhousie University - excellent (albeit lengthy) discussion with truly relevant advice and 2nd from the Admin here on our forum:

This plot another way to visualize the rate of loss of SoH:

And another chart in progress - rate of change of Soh:

Reference for climate zones in table:

I am also adding the entire AC/DC post-charge range prediction history of my car for those interested in long term trends including winter - summer variations etc - of course my car in a hot climate. Predictions are just that and not considered indicative of actual consumptive range.

Possible trends emerging (not yet statistically valid) for SoH retention in colder vs hotter climates - Li ion batteries generally do not like heat stress so do not do as well in very hot climates.

Here is the average trip data from your MyPorsche or Web Site data lists - remember these numbers are highly generalized in their own way being 1) averaged over a trip length, 2) the range her his simply calculated from the reported average miles per kWh attained regardless of trip length and the average applied to a fully (1005) SoC to guesstimate a max. range. All sorts of variables can effect that estimated range both positive and negative is again just a guide:


'Raw' averaged consumptive data from my car for it's entire use history:

And a simple calculation to output a maximum range using the reported average mi/kWh per trip (see provisos above):

And here is every charging session (might be missing 2 but checking!) for both at home AC and on the road DC charging in kW into car:

And a overly simplistic (think most negative calculation for range as of course near 80-90% of my trips are dominated by short and truly inefficient driving metrics).

If I focused only on the longer more efficient trips I see far better efficiencies in the range of 2.6-2.9 mi/kWh.

________________________________________________

Here is a recent addition (June 2023) from another years worth of data at odometer ca 11,000 miles from Forum Mbr. @TXAG - hopefully doesn't mind me copying here from his post in this thread #37 - another way to display SoC and PCM predicted ('Guessometer') Ranges:

Climate Zone = Hot
Model = 2022 RWD Taycan with PB+
Mileage = ca 11,000 Miles

Some external data from these links:

https://www.geotab.com/blog/ev-battery-health/
https://www.geotab.com/blog/ev-range-impact-of-speed-and-temperature/
https://www.geotab.com/blog/ev-range/

Here are some addl. variables that were documented in a much larger dataset involving non-Porsche EVs (links above) which clearly indicated excessive use of DC charging in these same hot climates has a further negative impact on SoH over time - the first chart's Level 1 charging is not really relevant as extremely few of us would use a std. wall outlet to charge our car! The Level 2 charging curve is relevant but our data suggest more of an impact than for the population of cars in this story;

An envelope of all data - the lone Porsche data point appears optimistic for most i.e. 5 of the 10 forum cars are below 91% SoH at under 20K Miles (vs 91% at 62K miles on the Porsche Marketing car) - however, as pointed out by @rs38 , there is clearly potential for 1 to two percentage points seasonal variation which is not universally represented in our data to date.

SoH plotted against model year and build date - don't have exact months for many of the German Forum and some of teh US Forum cars (hence couple of rows in data) but fairy clear trends.

______________________________________________________________
How many of you asked for or were provided data on the SoH of your PB+ battery on delivery?
I certainly did not have this on my delivery list to ask when I got mine , but would be useful to set a baseline if that data available.

Here is a readout of my current SoH which may or may not be an entirely accurate record of the true SoH. Nonetheless it would be interesting if all those who have a proper OBDII could read off their SoH and mileage to start to see if there are trends pt. forward with again the proviso that we first might need to establish how accurate these OBDII snapshots actually are.

TBH I thought my SoH would be higher considering I only have 4000 miles or so on the clock and only ca 300 kWh of direct 'fast' charging at EA stations to date - but I am entirely ignorant as to what the delivery SoH starting pt. should be.

So at a minimum say share:

1) Delivery Soh - suspect very few if any actually have this?
2) Current SoH
3) Current mileage
4) kWh DC charging (assume remainder at home or work/destination EVSE) - see #3 below on how to obtain.
5) Build date (or just MY if you're not sure)

For me:
1) unknown
2) 92.7%
3) 4000 miles
4) 303 kWh
5) Oct 2021

Could add # times charged to 100%, how often charge dropped below 20 or 10%, and more but asking a lot already!

Cheers, C.

PS: I'm using the Vgate's vLinker MC+ OBDII with a Bluetooth 4.0 connection to the Car Scanner iOS app.

 

[Scandinavian]

Here is some information from my car, 2020 Turbo.

1) unknown
2) 90.3%
3) 23 230 miles
4) no idea on where to find this information. But quite frequent charging on HPC’s when travelling.

 

[ciaranob]

Here is some information from my car, 2020 Turbo.

1) unknown
2) 90.3%
3) 23 230 miles
4) no idea on where to find this information. But quite frequent charging on HPC’s when travelling.

In regards the DC charging info you can retrieve this from your charging account in the App i.e at bottom right of the App's main screen, tap Account and then chose Charging Service and then under Transactions should be a list of all DC charges you have completed since you owned the car PRESUMING you have not reset the whole system.

 

[Scandinavian]

In regards the DC charging info you can retrieve this from your charging account in the App i.e at bottom right of the App's main screen, tap Account and then chose Charging Service and then under Transactions should be a list of all DC charges you have completed since you owned the car PRESUMING you have not reset the whole system.

Yes there is a list of all invoices for the charges, but there is no summary, just invoices. And I have about 175 of these on the porsche account, plus a number with Shell, Fastned, EON and Tesla that are all separate. I thought that statistic would be bisible in the Car Scanner app??

 

[ciaranob]

Yes there is a list of all invoices for the charges, but there is no summary, just invoices. And I have about 175 of these on the porsche account, plus a number with Shell, Fastned, EON and Tesla that are all separate. I thought that statistic would be bisible in the Car Scanner app??

Ah indeed, understood - that would be a chore to go back through - I didn't see that metric in the Car Scanner App straight off but need to look back through the bizillion sensor measurements it includes!

Would be nice if the Porsche App separated this out for you (which it doesn't)!

 

[ciaranob]

Simplest of plots with logarithmic curve (entirely understand there are many many variables here and of course a tiny population from the forum so far!) of reported SoH vs mileage dug out from @Dee 's original thread and from here. 2020, 2021 and 2022 cars used.

And of course there is a massive amount of data for EVs on all sorts of battery performance variables out there - nothing new here - just showing a couple but not trying to deep dive a rabbit hole and this has been discussed elsewhere on the forum - just interesting to plot our Taycan data against some industry std which I'm sure if I searched more I could find published already!! :

Somewhat dated example and Tesla focused:

https://maartensteinbuch.com/2015/01/24/tesla-model-s-battery-degradation-data/

Another set of variables:

 

[ciaranob]

Here's a site from 2020 reports on degradation that has a 'Comparison Tool' you can play with - not much to it but spans 6 years of data.

'Layman's' Article on degradation:
https://www.geotab.com/blog/ev-battery-health/
Tool:
https://www.geotab.com/fleet-management-solutions/ev-battery-degradation-tool/

A common observation from industry research articles and repeated here is the increased degradation in hotter climates such as Houston/Arizona etc. but a very minimal difference i.e. nothing to sweat about (intended ) being ca. .05% more over 4 years

Linkt to their Temperature Tool:

https://www.geotab.com/blog/ev-range/

 

[ciaranob]

Decent summary of how many variables there are in respect defining what we mean by and measuring SoH and how a measure of this is for example dependent on many aspects of battery cell condition alone (as also pointed out by @Dee in his thread)

https://www.mpoweruk.com/soh.htm

 

[Tooney]

Decent summary of how many variables there are in respect defining what we mean by and measuring SoH and how a measure of this is for example dependent on many aspects of battery cell condition alone (as also pointed out by @Dee in his thread)
https://www.mpoweruk.com/soh.htm

Thank you for the link to the Electropaedia article about SoH.

Before I read the article I did not know what SoH actually meant. I thought I did know what SoC meant.

After reading the article you posted and the same site's SoC article, I now know for both SoH and SoC,
--it all depends,
--SoC and SoH values are estimates, highly dependent on many variables, and
--differ depending on what theoretical basis is used to "define" them.

It would be nice to know if the SoC that my Taycan reports is based on the battery's rated capacity or its "current/most recent" capacity, but I'm gonna trust that Porsche has figured out what's best for me.

Ignorance can be bliss.

 

[Art]

So.. was there plan to collect this data? Sounds interesting. Here's two dot's from Finland:
2020 4S 31000 km 90.55%
2022 CT 1950 km 94.20% (loaner while uPdate)

UPD:
Read with reliable app made in country which invades it's neighbour countries.

 

[Scandinavian]

So.. was there plan to collect this data? Sounds interesting. Here's two dot's from Finland:
2020 4S 31000 km 90.55%
2022 CT 1950 km 94.20% (loaner while uPdate)

Yes it would be nice to see the graph above populated with more data.

I guess we are all relying on the CarScanner app to get this data. And we have no idea how accurate this is.

@Dee triggered my curiosity by charging to 100%. I did that twice at hotel destination chargers and had the car ready for departure directly in the morning. Unfortunately I started the charging from about 35 to 40% and not a much lower SoC, since I had no way of knowing if the chargers were free or even working.
My result also showed a small increase in SoH from just below 90% to above after charging to 100%. So now after returning from our 8500 km road trip, I intend to do a range test by charging to 100% and then driving in a civilised manner to a SoC in single digits and charging back up yo 100%. By recording the consumption over that drive together with the distance travelled should also give an indication of the battery capacity.

 

[ciaranob]

Yes it would be nice to see the graph above populated with more data.

I guess we are all relying on the CarScanner app to get this data. And we have no idea how accurate this is.

@Dee triggered my curiosity by charging to 100%. I did that twice at hotel destination chargers and had the car ready for departure directly in the morning. Unfortunately I started the charging from about 35 to 40% and not a much lower SoC, since I had no way of knowing if the chargers were free or even working.
My result also showed a small increase in SoH from just below 90% to above after charging to 100%. So now after returning from our 8500 km road trip, I intend to do a range test by charging to 100% and then driving in a civilised manner to a SoC in single digits and charging back up yo 100%. By recording the consumption over that drive together with the distance travelled should also give an indication of the battery capacity.

Here you go - found another user point but bit of an outlier and measured by dealership not indep OBDII - included though.

I will start to post and update this chart at the top of the thread (post #1) once we get a little more critical mass

A question mark means I am not certain re input - help if you can!

Curious that the two 2020's appear to retain a better SoH over time - of course not statistically significant at all with two data points! But w/o these two pts. the R2 would be much higher.

 

[Dee]

1) Unknown
2) 91,44%
3) 25000 kms (16.000 mls)
4) hardly any DC charging, mostly 10kW chargers.
5) 04-2020.

 

[ciaranob]

1) Unknown
2) 91,44%
3) 25000 kms
4) hardly any DC charging, mostly 10kW chargers.
5) 04-2020.

Dee, can't believe I don't know this and apparently too lazy to dig back through older posts to find out , but what model do you drive - want to say Turbo but maybe 4S? - so its prob a Turbo S .

Ah - must have misread your entry - so the change to higher 100% charging free is up to the higher mileage .- I will change.


Hopefully this more accurate?

 

[Dee]

Dee, can't believe I don't know this and apparently too lazy to dig back through older posts to find out , but what model do you drive - want to say Turbo but maybe 4S? - so its prob a Turbo S .

Ah - must have misread your entry - so the change to higher 100% charging free is up to the higher mileage .- I will change.

Yeah, pick what you want as it's just a sort of approval to use my data, it's a Turbo S indeed.
Note that my SoH is calculated more accurately since I've started to charge to 100%, it probably was >91,44% all before.

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