How-to Recalibrate your SoH.

[Sace]

It is the same scale as CarScanner always shows, but I do not know why the photo became so different.
’I have had two modules replaced before and now it looks bad again.
’Here is another attempt at showing the normal picture scale

Actually surprised that you can have so much difference between the cells without any errors showing. The fact that the car keeps driving with no warning until it’s completely dies is disturbing. Hopefully the new software will take care of this so we will know it before the car is stuck somewhere unable to drive.

Are you taking the car in for inspection soon?

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[Scandinavian]

Actually surprised that you can have so much difference between the cells without any errors showing. The fact that the car keeps driving with no warning until it’s completely dies is disturbing. Hopefully the new software will take care of this so we will know it before the car is stuck somewhere unable to drive.

Are you taking the car in for inspection soon?

Yes the car is in for all recalls, brakes, battery related, plus another one, on the 7th of January. I am only using the car for local drives at the moment, so no real good driving statistics either. Short trips only so the consumption will be all over anyhow.

But touch wood, no fault messages so far

 

[FrostDrive]

Nice reading. But, is it good or bad in long term for the battery tondo this. I learn stay at 100% for more than minutes is not good. But, will the cells be more balanced maybee it can compensate. Dont think its good to do this often but once a half-year may be ok?
Dont sit more than 6,5h on 100%, and not in hot temp

So to make it easy.
Come home with 1-2% at 15-16.00. Lock.
22:30 or after 6,5h start charging.
Adopt charging speed to departure -6.5h.
After 100% charge. Lock, wait 6,5h.
Read SOH and cell voltage. Drive down battery to at least 80%.

This will be my plan when I know I will drive 100km+ next day.

 

[Rik_CT4s]

Trying the rebalancing process once again since now I am equipped with carscanner and the MC+ Vgate. Works well!
Loads of useful data I must say. I started with 88.1% and currently I read 89.66% on carscanner, this after leaving it overnight with 100% SOC.
Today I drove it empty 0% (see pic) and I believe not much was left in the battery. well at least there is quite some more juice in than I expected!

I leave it overnight now at 0% and see what happens. Tomorrow morning I start the charging process to 100% and leave it at that charge overnight again. Let's see what happens. But did gain something already. From initial first check 88.16% to now 89.66%. Perhaps can hit 90%, let's see.

It was great to see the red critical battery warning pop up, as well as the snail icon .

Turbo S Cross Turismo MY22. 50.000km
Netherlands.

 

[F1Ruaraidh]

What you have done by going bottom to top slowly then allowing time for the passive rebalancing to take effect is to fully rebalance all the cells in the pack and recalibrate (relearn really) the whole min/max *SoC* algorithm.

This is NOT SoH. Only if the pack is really horribly out of balance (if you rapid a lot and never leave the pack to rebalance) will you pick up a few tenths of SoH which is what you are finding.

You don't (and in fact definitely shouldn't) leave the pack at 0% overnight. There's no need. It's the top of the pack that needs to sit to rebalance not the bottom.

 

[gtm]

You don't (and in fact definitely shouldn't) leave the pack at 0% overnight. There's no need. It's the top of the pack that needs to sit to rebalance not the bottom.

Straight from Porsche. https://static.nhtsa.gov/odi/tsbs/2024/MC-11005773-0001.pdf
discharge to 1-2%, which really isn't 1-2% and let it sit.

 

[Berti123]

Loads of useful data I must say. I started with 88.1% and currently I read 89.66% on carscanner, this after leaving it overnight with 100% SOC.

This is interresting. From which SoC was it charged up to 100% SoC?
I might try this as well.

 

[Rik_CT4s]

I let it sit today at 0% for about 8hrs....and just checked Carscanner. Now at 89.92% so up a bit. I have just started the charging process....i will get it up to 100% and leave it for the day (tomorrow). Let's see if I can hit 90%....would be great.
Fun fact. I let it sit for 8hrs at 0% (well 0%) and just woke the car up and I was at 1% / 3kms without charge. Something happens, for sure.
Tomorrow another carscanner check! To be continued!

 

[SergeyIndy]

What you have done by going bottom to top slowly then allowing time for the passive rebalancing to take effect is to fully rebalance all the cells in the pack and recalibrate (relearn really) the whole min/max *SoC* algorithm.

This is NOT SoH. Only if the pack is really horribly out of balance (if you rapid a lot and never leave the pack to rebalance) will you pick up a few tenths of SoH which is what you are finding.

You don't (and in fact definitely shouldn't) leave the pack at 0% overnight. There's no need. It's the top of the pack that needs to sit to rebalance not the bottom.

Please do not advise if you have not read the correct procedure in the TSB that we have shared on the forum and @gtm just linked again. The "sitting" is instructed to be for 6.5 hours at each end.

 

[Rik_CT4s]

This is interresting. From which SoC was it charged up to 100% SoC?
I might try this as well.

Cant exactly recall, but low SOC.
Now I am monitoring closely and went down to zero (0%)....and let it sit at zero for about 8hrs without communicating with the car (no apps etc). Currently nearing 90% SOH....and as we speak the charge starts to 100% again. Tomorrow another Carscanner check!
Charging at home. 11kw/h tops!

 

[Rik_CT4s]

Please do not advise if you have not read the correct procedure in the TSB that we have shared on the forum. The "sitting" is instructed to be for 6.5 hours at each end.

I have waited minimum 6.5hrs...more close to 8hrs....i just started the process to start to 100% now.
I came from 88.16%....definitely it does sth to my battery....as nearing 90% SOH from my measurement just now.
Hopefully I can get some juice "back".
Having said that, today I managed to empty the battery within 200km!!! Haha....great fun time on the road though....until the power backed down on me....and just at that point a BMW M popped up next to me at the traffic light....I was then forced to look at my navigation...

 

[SergeyIndy]

Cant exactly recall, but low SOC.
Now I am monitoring closely and went down to zero (0%)....and let it sit at zero for about 8hrs without communicating with the car (no apps etc). Currently nearing 90% SOH....and as we speak the charge starts to 100% again. Tomorrow another Carscanner check!
Charging at home. 11kw/h tops!

The part that you should be capturing are cell charts with SoC and Voltages. Those are useful to detect outliers that can potentially lead to bad cells.

 

[Rik_CT4s]

The part that you should be capturing are cell charts with SoC and Voltages. Those are useful to detect outliers that can potentially lead to bad cells.

I did....looking good earlier. All stable with very minor disprepancies. Will post all tomorrow for reference

 

[F1Ruaraidh]

Please do not advise if you have not read the correct procedure in the TSB that we have shared on the forum and @gtm just linked again. The "sitting" is instructed to be for 6.5 hours at each end.

Fair enough. It's not a true zero then by any means.

All it's doing is allowing settling. A pretty minimal effect even for a badly out of balance pack because the cell voltages are much closer at the bottom.

Be very interested in seeing the deltacell minmax before and after 6 hours. TSB feels very much like a fingers crossed and thumbs pressed.

None of this is going to recover much capacity. It's just a service balance.

Tesla service menu does this overnight for you while connected to your charger but its only needed really on LFP cells as the SoC curve is so flat. Much less necessary on NMC.

Feels like Porsche still on the steep part of the learning curve....

 

[F1Ruaraidh]

Straight from Porsche. https://static.nhtsa.gov/odi/tsbs/2024/MC-11005773-0001.pdf
discharge to 1-2%, which really isn't 1-2% and let it sit.

Yes the key phrase there is "customer facing".....

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