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

[tchavei]

Ok. Got my vLinker today

1) Unknown
2) 97.47%
3) 1401 Km
4) Only DC 50kW (about 300kWh total charged so far). Charged once at 160kW (55kWh added)
5) Build date April 23rd 2023 (MY23)
6) Warm Climate (37N)

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[ciaranob]

@Raphie
@tchavei

Data uploaded into chart in Post #1

 

[tchavei]

BTW, just want to add something here since I've been marvelled about the correlations I have been finding between my two decade old hobby experiences with Lipoly (lithium) packs and our cars.

Back in the day, when I charged lithium packs, the golden rule after a day "at the field" fast charging was to give a full and slow charge at home. Why? Because albeit I always used cell balancers while charging, during fast charging, there was no way of the balancers being capable of burning (through resistance and heat) the excess voltage of some cells in that short amount of time.

On a slow charge however, once the pack reached 90%+ the cell balancers had plenty of time of discharging the highest cells until all cells were within 0.001V this would also cause the last 5-10% charge taking way longer since the charging process was fighting the "cell balancing" discharging process.

Now, we know that's unthinkable that our cars don't cell balance (they do) but maybe we're forgetting that most likely, they're balancing the cells exactly like we used to do 15 years ago... Mostly at the top end of the charge. That's probably also the explanation why people see an SoH improvement after slow charging to 100% simply because whatever system is in the Taycan has time to discharge those single cells reaching 4.20V before the others so that all cells reach the closest and highest voltage between themselves.

Hence I believe, the SoH is nothing more then the average measurement of the deviation between the highest and lowest cell voltages.

I guess a monthly slow charge from very low to 100% might be a good idea after all

PS: and yeah, "back in the day" we used to charge our packs up to 4.34V which was very close to thermal runaway in name of "winning"... ?

 

[Scandinavian]

BTW, just want to add something here since I've been marvelled about the correlations I have been finding between my two decade old hobby experiences with Lipoly (lithium) packs and our cars.



Now, we know that's unthinkable that our cars don't cell balance (they do) but maybe we're forgetting that most likely, they're balancing the cells exactly like we used to do 15 years ago... Mostly at the top end of the charge. That's probably also the explanation why people see an SoH improvement after slow charging to 100% simply because whatever system is in the Taycan has time to discharge those single cells reaching 4.20V before the others so that all cells reach the closest and highest voltage between themselves.

That seems to be my experience as well. I have just been on a 8000 km trip with Fast Charging most of the time. Just two slow overnight charges.

Back home I arrived with 9% SoC and have now charged the car up to 100% and drove the car for 150 km. The SoH increased by another % and now shows 90.42%.

The BMS and PMCC also reduced the charging power from 11 kW to about half that for the last 8-10% SoC.

So seems well worth using AC up to 90-95% ever so often, but driving the car directly once charged.

 

[tchavei]

That seems to be my experience as well. I have just been on a 8000 km trip with Fast Charging most of the time. Just two slow overnight charges.

Back home I arrived with 9% SoC and have now charged the car up to 100% and drove the car for 150 km. The SoH increased by another % and now shows 90.42%.

The BMS and PMCC also reduced the charging power from 11 kW to about half that for the last 8-10% SoC.

So seems well worth using AC up to 90-95% ever so often, but driving the car directly once charged.

Yeah but that means I have to find a way of charging slow AC without being charged by the minute... It's no fun charging the car 20-80% at 50Kw for €9 while the same on AC at 7.5Kw costs €50.

I swear I hate charging by minute.

 

[ciaranob]

That seems to be my experience as well. I have just been on a 8000 km trip with Fast Charging most of the time. Just two slow overnight charges.

Back home I arrived with 9% SoC and have now charged the car up to 100% and drove the car for 150 km. The SoH increased by another % and now shows 90.42%.

The BMS and PMCC also reduced the charging power from 11 kW to about half that for the last 8-10% SoC.

So seems well worth using AC up to 90-95% ever so often, but driving the car directly once charged.

All good points and observations - the SoH chart though I see as tracking larger scale trends towards that initial more rapid drop to 90% and most curious to start getting data from cars that are 2+ years on the road, preferably 3+, with mileages above 25K mikes to see how/if the curves flatten out as other data suggest they should do.

I regard any specific SoH reading in the chart always as a +/- 1% data point to cover your and others including my own experience in regard SoH fluctuation.

 

[Scandinavian]

Yeah but that means I have to find a way of charging slow AC without being charged by the minute... It's no fun charging the car 20-80% at 50Kw for €9 while the same on AC at 7.5Kw costs €50.

wow that is some price per minute alright.

But I guess charging at 50 kW is also acceptable, maybe ever so often charge above 90%? It is only 0.5C charging rate.

I know that many Tesla owners charge up to 95% on a regular basis to get good values from their batteries. But they drive them when charging has finished and do not let them stand

 

[tchavei]

wow that is some price per minute alright.

But I guess charging at 50 kW is also acceptable, maybe ever so often charge above 90%? It is only 0.5C charging rate.

I know that many Tesla owners charge up to 95% on a regular basis to get good values from their batteries. But they drive them when charging has finished and do not let them stand

You know what?

I think the fact that some dealerships charge the car to 100% before delivery is taking an immediate toll. When my SA sent me the final pics of my car waiting for me in the showroom, it was charged to 99-100% and it was wednesday. I picked up the car on the next monday. So the car sat there at 100% at least 5 days

 

[WasserGKuehlt]

1) unknown
2) 93.3
3) 8100
4) unknown
5) 11/2022

My previous readout was 95.5 at 5100mi; in the meantime I’ve added maybe 4-6 DC charging sessions, and charged to 100% quite a few times - I’d say about 10?, a couple DC and the rest at home.

I’m hoping SoH is done dropping ?, only had the bloody car for less than 5 months now.

 

[ciaranob]

1) unknown
2) 93.3
3) 8100
4) unknown
5) 11/2022

My previous readout was 95.5 at 5100mi; in the meantime I’ve added maybe 4-6 DC charging sessions, and charged to 100% quite a few times - I’d say about 10?, a couple DC and the rest at home.

I’m hoping SoH is done dropping ?, only had the bloody car for less than 5 months now.

Will upload today - hate to say it, but mine had a similar decline and still going - I need to take another reading!

 

[ciaranob]

1) unknown
2) 93.3
3) 8100
4) unknown
5) 11/2022

My previous readout was 95.5 at 5100mi; in the meantime I’ve added maybe 4-6 DC charging sessions, and charged to 100% quite a few times - I’d say about 10?, a couple DC and the rest at home.

I’m hoping SoH is done dropping ?, only had the bloody car for less than 5 months now.

Plotted!

 

[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.

One dot update from our cold country (today max 24C) as my MY20 reaches 40000km. SoH now 91.3%.
So it seems to raise.. This car has done it's first 20k in Madrid /Spain area which is much warmer than here..

 

[ciaranob]

One dot update from our cold country (today max 24C) as my MY20 reaches 40000km. SoH now 91.3%.
So it seems to raise.. This car has done it's first 20k in Madrid /Spain area which is much warmer than here..

Charts updated in Post #1 - thx for sharing!

 

[ciaranob]

New 40K mile update added - see post 1 - sent via private message so will honor that unless said person wants to add more here - climate zone confirmation pending ....

 

[SergeyIndy]

This is very helpful thread. Mine supposed to be heading to me from the port this week. Top of the list is to get SoH on delivery and not let them DC blast it to 100% if I can help it as may be required for the PDI. However, I will be there watching it every minute before I take it for the PPF. Anything else I should get as far as data from the PDI process?

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