Battery state of health on used models

[JBW1273]

Hi. I was emailing with a Porsche dealership about a used Taycan. I asked if they would provide me the state of health of a particular used Taycan. They told me that was something the service department will handle, and that it costs $3,000 because they have to have the car "on" for 24 hours and then take a test drive. So . . . is this for real? The battery state of health is the most important part of an EV, and it is something that is readily ascertainable. I have had pre-purchase inspections on other used cars before, and I have no problem paying for that. But $3,000?!!! For something that seems so easy to determine?

I would be interested to hear other people's experience on this issue to get a sense for whether this is standard or is specific to this dealership and/or just another item to be negotiated.

Jason

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[Vincent_Frederick]

That's crazy! Maybe use an OBD to check and that's It, I don't know how accurate is It but better than paying 3000 for sure

 

[Fish Fingers]

I would tell them to stick it and go elsewhere.

Makes me wonder if the car has some kind of history and they want you to buy it blind.

 

[Fish Fingers]

The EU have got the right idea on this imo....

Regulation	Implementation Date	Who is affected?
EU Carbon Reporting	2025	New batteries must declare carbon footprint.
EU Battery Passport	Feb 2027	New EVs must have a QR code for SOH/Life data.
Euro 7 Standards	2027–2028	New cars must meet minimum health/durability floors.
Used Car Market	Voluntary Now	Dealerships are adopting it early to sell cars faster.

 

[whitex]

To do a complete battery health test per Porsche specification, yes, you have to do a full discharge cycle. Still, $3,000 is a rip off (are they charging for labor for every hour the car is charging in the shop?). However, you can get a current SoH (state of health) using many OBDII readers (like CarScanner, including its free version) or the even less expensive connection Tcan tool below:
https://www.taycanforum.com/forum/t...an-battery-diagnosis-for-the-community.27701/

The instantaneous reading will not be as meaningful as one after a full battery cycle (discharge the battery all the way, them charge it back, etc), but can give you a good idea.

@JBW1273 , where is the car you're interested in?

 

[MrJones02]

Buyers just want a ballpark idea, nobody really cares if the quick standard readout shows 91% and the full test with complete battery-cycle etc ends up showing 89.9%

Just the fact they can tell you with a straight face this will cost you $3000 is crazy.

 

[69Mach390]

Hi. I was emailing with a Porsche dealership about a used Taycan. I asked if they would provide me the state of health of a particular used Taycan. They told me that was something the service department will handle, and that it costs $3,000 because they have to have the car "on" for 24 hours and then take a test drive. So . . . is this for real? The battery state of health is the most important part of an EV, and it is something that is readily ascertainable. I have had pre-purchase inspections on other used cars before, and I have no problem paying for that. But $3,000?!!! For something that seems so easy to determine?

I would be interested to hear other people's experience on this issue to get a sense for whether this is standard or is specific to this dealership and/or just another item to be negotiated.

Jason

What year is the used one?

What are you going to do with the information?

If it says 87% or 92% or any normal number in that range, will it keep you from buying it?


You could do the absolutely “easiest” SOH test- go look at the estimated range on the dash and see if it’s somewhat normal for this time of year.

In the very rare circumstances that the SOH was super low, is that really even that bad? It would just mean that during the 8 year warranty period you would get a brand new battery.

On a used EV, that’s definitely not the worst thing that could happen.

I honestly wouldn’t worry about SOH (and I didn’t either when I bought my used 2024 a few weeks ago).

 

[Gkwan]

I agree with all the replies here, I'd just add that from commercial point of view they way they are treating you while you're not even a customer is "not good".
Imagine how they'll treat you after you bought the car and you are "tied" to them ?
So my advice as former Sales Exec (semiconductor) is "Run away from these guys".

 

[TonyR]

Hi. I was emailing with a Porsche dealership about a used Taycan. I asked if they would provide me the state of health of a particular used Taycan. They told me that was something the service department will handle, and that it costs $3,000 because they have to have the car "on" for 24 hours and then take a test drive. So . . . is this for real? The battery state of health is the most important part of an EV, and it is something that is readily ascertainable. I have had pre-purchase inspections on other used cars before, and I have no problem paying for that. But $3,000?!!! For something that seems so easy to determine?

I would be interested to hear other people's experience on this issue to get a sense for whether this is standard or is specific to this dealership and/or just another item to be negotiated.

Jason

Get the free software off @ct14garage on here and an OBD to internet cable from Amazon to connect it to your laptop. If they will let you plug it in the OBD port you can then read the SOH cell by cell for the princely sum of $10

 

[whitex]

I agree with all the replies here, I'd just add that from commercial point of view they way they are treating you while you're not even a customer is "not good".
Imagine how they'll treat you after you bought the car and you are "tied" to them ?
So my advice as former Sales Exec (semiconductor) is "Run away from these guys".

^THIS

 

[ovonrein]

You could do the absolutely “easiest” SOH test- go look at the estimated range on the dash and see if it’s somewhat normal for this time of year.

Agree with your post. For a tiny bit more science, I believe that the range guesstimate is based on the average consumption in the Trip Computer/Since charge. So divide that guesstimate by that reported average and the remain % to find to the kWh for a full charge. That divided by the nominal battery capacity is the "SOH".

 

[whitex]

Agree with your post. For a tiny bit more science, I believe that the range guesstimate is based on the average consumption in the Trip Computer/Since charge. So divide that guesstimate by that reported average and the remain % to find to the kWh for a full charge. That divided by nominal battery capacity is the "SOH".

Really not so simple, if the car idles in the showroom, or it taken on test drives by various people, or driven by staff. I can change my guessometer quite significantly depending on how I drive. A day at a track will sink it like a stone, which does not indicate a bad SOH of the battery.

 

[ovonrein]

Yes, it is not that simple. A very varied usage pattern like yours will certainly ruin my calculation Though your track usage should sink both the range guesstimate and the Trip/Since charge readings.

 

[pteron]

For what it's worth, I asked for the SOH before buying my car. The Porsche dealership reported 91%. +/- 5% I wasn't impressed but the car was otherwise perfect and the salesman asked why I was worried, it has an 8 year warranty.

I bought the car, got it home and bought the kit for the ct14garage software, drove the car down to 2%, left it to balance, charged it to 100%, left it to balance and measured the battery SOH.

It was 91%.

 

[whitex]

I wasn't impressed but the car was otherwise perfect and the salesman asked why I was worried, it has an 8 year warranty.

The answer to this question is because you like to drive your cars, and Porsche gives no guarantees how long they take to repair the batteries. Search for stories here how long some people had to wait for battery replacements.

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