A SWAG - How long will my Taycan battery last?

[daveo4EV]

Team,

from history and posting this comes up a lot. How long will my Taycan battery last?

The honest answer is: No one really knows - but a lot of people have a pretty good idea.

from this posting - https://www.taycanforum.com/forum/threads/another-charging-question.10726/#post-155263 - I'm sharing a summary of my personal conclusions.

we can however make some SWAG's at what the underlying limits of the Taycan battery are based on Porsche's warranty limits and making well reasoned inference that Porsche's warranty limits are "conservative" - i.e. I would believe the hope that in the common case the battery will easily exceed the warranty claims by some significant margin - the exact magnitude of this margin is likely to be a closely guarded trade secret.

Based on some general industry knowledge and reverse engineering Porsche's warranty limits I think one can say the following are the general parameters of the Taycan's expected battery life.

1250-1500 500-800* - full charge/discharge cycles
40,000 to 50,000 kWh's in & out in terms of battery usage

* - revised downward given kWh capacity of this many "full" charge cycles - no one outside of Porsche honestly knows - so please again use your best judgement as to if you agree with me.

these numbers are inline with published industry standard LiON engineering cell specs - and show a healthy margin of error for Porsche's warranty to live with in based on my analysis (8 years/100,000 miles).

Expected life of a LiON battery is: the Battery will lose no more than xx% capacity in the defined warranty period. In the case of Porsche I believe the warranty is trigger at 30% total capacity lost (please feel free to correct me).

500 full charge cycles @ 83.4 kWh = 41,700 kWh's
800 full charge cycles @ 83.4 kWh = 66,720 kWh's
1250 full charge cycles @ 83.4 kwh = 104,250 kWh's
1500 full charge cycles @ 83.4 kWh = 125,100 kWh's

50,000 kWh @ 3.2 miles per/kWh consumption = 160,000 miles driving
30,000 kWh @ 3.2 miles per/kWh consumpption = 96,000 miles of driving

160,000 miles @ 10,000 miles a year = 16 years
160,000 miles @ 20,000 miles a year = 8 years

these are pretty common stats for a consumer grade street car. And most ICE vehicles will need some sort of major service in 160,000 miles - and battery cost is inline with any other major drive train component for this sort of longevity expectation.

Now Porsche states warranty is only after a loss of 30% total capacity in the warranty period - so some loss is expected - up to 30% apparently - this means your Taycan which could go about 270 miles when you drove it off the lot is expected to only be able to drive 189 miles towards the end of the warranty period on a full 100% charge.

I have no data/information as to how much "buffer" is built into by Porsche to these numbers. As to if Porsche hopes to exceed these expectations no one outside of Porsche knows this - I'm simply saying 189 miles of range at 99,999 miles and 7 years and 364 days would NOT trigger the battery's warranty.

DISCLAIMER: I have NO access to internal Porsche information - this analysis is for entertainment purposes only - it's not a binding analysis that you can take to your local service advisor.

I arrived at these conclusions from a broad experience with EV's and their general characteristics and reverse engineering various factors from generally true metrics we all can agree accurately represent the Taycan's consumption of battery power.

comment, questions, and discussion is welcome.

* - SWAG = Scientific Wild Ass Guess - yes data was used to infer the results, but it still is a reasonable guess as to the conclusion because it can't be proven, but the results asserted are reasonable from the premise.

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[JimBob]

I think you can simplify this a little. The thing that is most damaging to batteries is heat. You need heat if you want really fast charging, but heat causes adverse chemical reactions which will reduce battery capacity. You have some control over this in how you treat your batteries.

Batteries also degrade with time and you can't do anything about that.

Cycles are important but you have a lot of room here. Just think of commercial fleets using Lithium Ion batteries who recharge every night and are expected to go hundreds of thousands of miles.

If there is a criticism of the Porsche battery it is the rather puny warranty terms. Your chances of a successful warranty claim for usage is vanishingly small.

 

[daveo4EV]

If there is a criticism of the Porsche battery it is the rather puny warranty terms. Your chances of a successful warranty claim for usage is vanishingly small.

I agree - and this is most likely by design - I personally just find it useful to "recast" the warranty claims into different units of measurement - like you I believe it is illuminating

I do know that full charge/discharge cycle count is "a thing" for LiON batteries and an industry standard metric used to estimate longevity - 1000-3000 cycle count rated LiON cells is the industry norm from my last read of some specs in this space - with acceptable "loss" defined.

so temperature, cycle count, charging speed, and cell SOC% are the major factors that battery charging systems "manage" to achieve longevity goals…

again I just found it interesting to recast some of the Porsche warranty "claims" in terms of battery life - i.e. Porsche's warranty claims are going to be easily achieved and represent minimum high confidence results - Porsche's doesn't actually want to replace your battery under warranty - so they are going to be very conservative with their claims.

 

[Gubbjaevel]

Just re-read the warranty re: batteries.
At least here in Scandinavia; it says if your battery is 65% - they will repair it up to 70%+ to make you within the warranty. No more. So don't hope for too much, even in a warranty case.

I seem to remember some P exec said "in the day" (2019?) that changing batteries in the Taycan would be (memory-quote) "very easy". Will be interesting to see if it will be possible to change the whole lot for, let's say, a solid-state one when they show up.

 

[daveo4EV]

Just re-read the warranty re: batteries.
At least here in Scandinavia; it says if your battery is 65% - they will repair it up to 70%+ to make you within the warranty. No more. So don't hope for too much, even in a warranty case.

I seem to remember some P exec said "in the day" (2019?) that changing batteries in the Taycan would be (memory-quote) "very easy". Will be interesting to see if it will be possible to change the whole lot for, let's say, a solid-state one when they show up.

with some "bad" batteries already replaced by my local Porsche dealers - I can confirm the actual battery swap is "easy" - local Service manager said it's easier and faster than say a PDK transmission swap - and about as frequent - the only issues seems to be:

• logistics to receive the replacement part given physical size & weight
• new "lift" to properly support the battery during install and handle the weight

aside from the size/weight issue - the actual complexity of the battery swap is virtually no different than a new 12V battery - and some cooling fluid management - with some software configuration post install to train the vehicle about the new replacement unit.

I'd love an "upgraded" battery in the future - i.e. new tech or some such - but I'm not holding my breath for that even though it should be pretty straight forward since batteries are high modular.

 

[daveo4EV]

Just re-read the warranty re: batteries.
At least here in Scandinavia; it says if your battery is 65% - they will repair it up to 70%+ to make you within the warranty. No more. So don't hope for too much, even in a warranty case.

I seem to remember some P exec said "in the day" (2019?) that changing batteries in the Taycan would be (memory-quote) "very easy". Will be interesting to see if it will be possible to change the whole lot for, let's say, a solid-state one when they show up.

I would also agree not to expect "much" if you have a battery capacity warranty claim - we know the battery is some what modular internally so yeah they could swap modules to achieve battery health improvements without an entire replacement…

I am however dubious as to how many local shops would be qualified by Porsche to actually do that - I would fully expect them just to swap the offending battery for a full replacment - and then ship the "bad' battery to some central regional location where Porsche factory tech's "refurbish" bad batteries and those refurbished batteries become replacement parts for other vehicles - the factory Porsche tech's would certainly be allowed to swap battery modules and test and qualify remaining modules with no need to replace them.

 

[fgwinn]

.....50,000 kWh @ 3.2 miles per/kWh consumption = 160,000 miles driving
30,000 kWh @ 3.2 miles per/kWh consumpption = 96,000 miles of driving......

I am curious to know how you determined the 3.2 miles/kWh value. After 6400 miles in my MY22 CT4 (between November and April) my average consumption is 2.7 miles/kWh. I am getting as much as 3.1 miles/kWh on recent trips now that Winter is over. But, 3.2 seems overly optimistic.

 

[daveo4EV]

I am curious to know how you determined the 3.2 miles/kWh value. After 6400 miles in my MY22 CT4 (between November and April) my average consumption is 2.7 miles/kWh. I am getting as much as 3.1 miles/kWh on recent trips now that Winter is over. But, 3.2 seems overly optimistic.

yeah - I didn't want to low ball it - that's not the point of the posting

I've seen 3.2 in the past on some trips - but I agree we can shuffle the numbers around and yes 2.7 miles/kWh is also a number I've seen with my personal Taycan

the more interesting result in my mind is regardless of what efficiency number you use we can arrive at a "total expected kWh's" consumed number - which is a novel way to frame/consider "battery life" (at least it was novel to me - but maybe I'm just slow) - and not out of line with internal engineering/scientific rational used by industry battery design teams.

I agree we could re-run the numbers for 2.7 - but I don't want to turn this thread in a conversation about Taycan's efficiency - and low balling the number might raise the hackles of some Porsche faithful

here is the number of kWh's consumed for 2.7 miles/kWh

100,000 miles / 2.7 miles/kWh = 37,037 kWhs (still less than our 40,000 to 50,000 kWh battery life SWAG)
37,037 kWh / 83.4 kWh/cycle = 444 full charge cycles - still less than our 500-800 cycle swag

the exact numbers in my opinion are less important than what I found interesting - how many kWh's in/out of the battery are required to drive distance "n" - and if you look at the estimated longevity of the vehicle in miles, you can directly translate that to a meaningful load on the the battery over that many miles…

even with 2.7 miles/kwh we end up with a pretty conservative number being 50,000 kWh's might not be an unreasonable SWAG for expected battery life - it' certainly allows the car to driven enough miles in a reasonable and expected amount of time.

 

[fgwinn]

.....Now Porsche states warranty is only after a loss of 30% total capacity in the warranty period - so some loss is expected - up to 30% apparently - this means your Taycan which could go about 270 miles when you drove it off the lot is expected to only be able to drive 189 miles towards the end of the warranty period on a full 100% charge.

I have no data/information as to how much "buffer" is built into by Porsche to these numbers. As to if Porsche hopes to exceed these expectations no one outside of Porsche knows this - I'm simply saying 189 miles of range at 99,999 miles and 7 years and 364 days would NOT trigger the battery's warranty......

Next question....

I have managed to charge to between 260 and 270 miles a couple of times (extrapolated from an 85% charge indicating between 220 and 230 miles). How do we know that Porsche will use 270 as the denominator instead of the EPA estimate which is 215 for my CT4? 70% of 215 is only 150 miles which would pretty much preclude the warranty from ever being triggered in 8 years.

 

[XLR82XS]

I think you can simplify this a little. The thing that is most damaging to batteries is heat. You need heat if you want really fast charging, but heat causes adverse chemical reactions which will reduce battery capacity. You have some control over this in how you treat your batteries.

Isn't it extreme cold that is worse for batteries than heat? Exciting to see what's on the horizon with Quantum Scape in the next few years.

 

[Tsingtao]

I wouldn't worry about battery life. My previous EV lasted 7+ years with 8-10% (max) range loss when I ditched it for the Taycan. My guess is that everyone -- even the battery abusers amongst us who charge above 85% and tap DC fast chargers on a regular basis -- can expect at least 8-10 years of fun before battery depletion gets really obnoxious, i.e. something below 125 miles on a charge. And by then there will be some new and improved batteries that Porsche can install for us at a reasonably obscene price if we want to keep driving old Taycans. But the real reason not to worry is that by the time our Taycan batteries give out, there will be lots of 911 EVs (with light weight batteries) available and none of us will want to drive an old 5000 lb. Taycan.

 

[JimBob]

Isn't it extreme cold that is worse for batteries than heat? Exciting to see what's on the horizon with Quantum Scape in the next few years.

No. Current in a battery is generated by an electrochemical reaction which is temperature dependent. If you take a battery at say room temperature and fully charge it up, it will have positive charges on one terminal and negative on the other. Now take that same battery and drop its temperature down to say freezing. The positive and negative charges are still there but if you try to get current out of the battery than the output will be reduced as the electro chemical reactions have slowed down. The reduction in current output could be so low that the battery doesn't generate any output.. If you take the battery back up to room temperature, the reactions speed up and current output returns to normal.

The one case that could damage the battery is if you try to rapid charge a very cold battery.

In the case of a hot battery, the chemical reactions have speeded up so good for fast charging, but that can generate adverse chemical reactions which can damage the battery.

 

[Genau]

I seem to remember some P exec said "in the day" (2019?) that changing batteries in the Taycan would be (memory-quote) "very easy". Will be interesting to see if it will be possible to change the whole lot for, let's say, a solid-state one when they show up.

Here's the quote.

https://www.taycanforum.com/forum/threads/boy-i-sure-hope-there’s-an-upgrade-path.5865/post-81621​

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