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[FREE] tCAN-Pro - TAYCAN BATTERY DIAGNOSIS FOR THE COMMUNITY

Tooney

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In this case it's not accurate because you have a repaired battery with 3 brand new modules and all the rest are old degraded ones. So of course the tool will flag them!
I will improve the software so in the future it will better recognize those batteries that have been repaired in this foolish way by Porsche and not make the users panic!

You are not at risk for an imminent battery failure, but the truth is that Porsche shouldn't be doing this because it leads to these situations. With such a voltage delta your car will never work optimally as designed.

Modules should only be replaced with others in similar condition, mixing brand new ones with degraded old ones is not a good idea at all in any battery.
Is there anything in Porsche service instructions or procedures for replacing HV battery modules that deals with trying to match replaced modules with existing ones?

Is there any impact on overall battery SoH when some modules are replaced?
Normally when this is done SoH stays the same, gets better, gets worse?
 

RBGtaycan

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Well the problem with this battery is not that it is unhealthy per se, but rather that they installed brand new modules (100% SoH) on a battery with poor SoC (probably the SoH on all the other modules that weren't replaced is 70% to 80%, definitely not more than 80%)

So of course this causes massive imbalance and poor range which for sure you have.. I bet your range at 100% is 380km to 400km. Quite sure not more than 400km
On YOUR repairs to batteries, I presume you are placing bad modules with new modules?...so does that not create an inherent imbalance (unless the battery is very new)?
 
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ct14garage

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On YOUR repairs to batteries, I presume you are placing bad modules with new modules?...so does that not create an inherent imbalance (unless the battery is very new)?
Negative. I never use brand new modules UNLESS customer does the whole pack (either 33 or 28 in one go).

I buy as many second hand battery packs as I can. Often times from dealers that changed them and sell the old ones right away ?… any battery I can get my hands on

Pull out the good modules order them by SoH groups…. 70%…80%….90%

If battery with SoH 73% comes to replace three modules we install 3 modules with ~70% SoH so it will stay balanced and not affect range!
 
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ct14garage

ct14garage

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Is there anything in Porsche service instructions or procedures for replacing HV battery modules that deals with trying to match replaced modules with existing ones?

Is there any impact on overall battery SoH when some modules are replaced?
Normally when this is done SoH stays the same, gets better, gets worse?

Whether mixing them in is okay depends on the rest of the battery.If your pack is still around say 96% SoH, adding new ones isn’t a big deal.
But if the rest are down to 70%… forget it. That’s a bad move.

Some people think dropping in fresh modules won’t matter because the fresh modules are simply limited to the performance of the weakest module. Sounds logical, but it’s wrong.

The reality is:
New and old modules behave very differently in voltage, resistance, and temperature, impedance.

The BMS constantly struggles to keep them balanced, which leads to massive voltage delta, poor range, range loss while parking (as frequent balances occur)….

In the long run, both new and old modules suffer faster wear.

So unless the rest of the pack is still in excellent shape, mixing in new modules just creates new problems!
 


mokre

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Is it possible to "wear down" the newer cells first? (I'm wondering if the battery can be wear-levelled similar to how an SSD controller can level out the cell wear - I know they're different tech, just wondering if the maintenance philosophy carries over)
 

eddieterry

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Just got cable and the scan worked really quickly and well. All green but not sure what is a good or bad Delta. 2023 Taycan CT Turbo - Scan shown below:
Porsche Taycan [FREE] tCAN-Pro - TAYCAN BATTERY DIAGNOSIS FOR THE COMMUNITY IMG_2363
 
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ct14garage

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Is it possible to "wear down" the newer cells first? (I'm wondering if the battery can be wear-levelled similar to how an SSD controller can level out the cell wear - I know they're different tech, just wondering if the maintenance philosophy carries over)
No such thing for batteries
 


dooby

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My scan from my MY23 4S, about 19k miles. Only 20mV delta - same as my Energica :-D
No ARB6/ARB7/WRS1 symptoms either. It was charged to 100% for a long trip (thus presumably balanced) 2 days ago. Thank you Cristian for the app!

Porsche Taycan [FREE] tCAN-Pro - TAYCAN BATTERY DIAGNOSIS FOR THE COMMUNITY VIN_date_tim
 

yann27

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Porsche Taycan [FREE] tCAN-Pro - TAYCAN BATTERY DIAGNOSIS FOR THE COMMUNITY image (9)
Hello, here is mine, many thanks for the tool ! I'm quite concerned with the low isolation value on negative side when I see data over 600kOhms for some. Is there a risk using it daily with my family? Taycan 4S 2021 with 42k km. Concerning the balancing I never charge over 85% so I'm not too surprised that the balance is not perfect.
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