Useable battery - Are Porsche looking after us?

[Fish Fingers]

I was reading an article just now comparing a BMW i4 / Polestar 2 / Tesla M3 (BMW won btw) and was looking in the tech comparison at the end.

https://www.autoexpress.co.uk/bmw/i...tar-2-vs-tesla-model-3-2022-group-test-review

I was surprised to see how little reserve is kept in the battery compared to our Taycans.

I am assuming porsche is protecting the battery and future residuals at the expense of offering more range from new?

Which if correct, I see as a really good thing longer term.

Grid is BMW / Tesla / Polestar

V

The entry-level Taycan has a 79.2kWh battery with a usable capacity of 71.0kWh. This provides a range of 220 to 268 miles. Opting for the 93.4kWh Performance Battery Plus ups the usable capacity to 83.7kWh and increases the range to between 253 and 301 miles.

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[Bognar67]

I was reading an article just now comparing a BMW i4 / Polestar 2 / Tesla M3 (BMW won btw) and was looking in the tech comparison at the end.

https://www.autoexpress.co.uk/bmw/i...tar-2-vs-tesla-model-3-2022-group-test-review

I was surprised to see how little reserve is kept in the battery compared to our Taycans.

I am assuming porsche is protecting the battery and future residuals at the expense of offering more range from new?

Which if correct, I see as a really good thing longer term.

Grid is BMW / Tesla / Polestar

V

The entry-level Taycan has a 79.2kWh battery with a usable capacity of 71.0kWh. This provides a range of 220 to 268 miles. Opting for the 93.4kWh Performance Battery Plus ups the usable capacity to 83.7kWh and increases the range to between 253 and 301 miles.

Yes. According to the available data Taycan has most reserve by far. Although we do not know the official reason but seems good for long term/2nd hand buyers. Owners can't destroy much the battery with high level charges so the only sacrifice is shorter range.
Maybe later on it is also a possibility to make free more capacity as they learn the habit of the battery or developing battery management.
What we do not know how much is the reserve at low/high end level of charge from this.

 

[Atipical]

That's a really good point that I didn't really think about. Over time the battery will inevitably degrade in it's ability to reach "100% capacity" so perhaps the buffer helps guard against that...? Otherwise Taycans would have an additional 10% more range (equating to roughly 25-30 more miles from new).

 

[Fish Fingers]

It would be interesting to know what is going on and the thought process behind it?

The only thing I can say, is that I am glad Porsche are doing it.

It should help preserve the battery and would be a huge advantage over other cars in the 2nd hand market. And hopefully retained values.

It could be similar to Rolex, making sure used values are strong for their customers.

Typical Porsche. Understate and over perform ?

 

[martinmanyhats]

I’ve also seen the comment on a review vid (can’t recall which) that suggested the headroom also allows for regen braking when the battery is nominally at 100%. Which makes some sense,

 

[Bognar67]

I’ve also seen the comment on a review vid (can’t recall which) that suggested the headroom also allows for regen braking when the battery is nominally at 100%. Which makes some sense,

Absolutely. The performance issue of limited capacity is to offer same pedal (both) and regen feel wide range of conditions independently SOC, weather, temperature of battery etc.
Rather this balance than 15-25 real miles extra range. Additionally it saves battery life as well.

it also allows higher kW charge at higher SOC since real 100% capacity is not a 100% of the shown charge level. So charging time is faster overall.

 

[SHM]

I was reading an article just now comparing a BMW i4 / Polestar 2 / Tesla M3 (BMW won btw) and was looking in the tech comparison at the end.

https://www.autoexpress.co.uk/bmw/i...tar-2-vs-tesla-model-3-2022-group-test-review

I was surprised to see how little reserve is kept in the battery compared to our Taycans.

I am assuming porsche is protecting the battery and future residuals at the expense of offering more range from new?

Which if correct, I see as a really good thing longer term.

Grid is BMW / Tesla / Polestar

V

The entry-level Taycan has a 79.2kWh battery with a usable capacity of 71.0kWh. This provides a range of 220 to 268 miles. Opting for the 93.4kWh Performance Battery Plus ups the usable capacity to 83.7kWh and increases the range to between 253 and 301 miles.

Those numbers are not correct.
Neither is charge speed, article claims.

 

[SHM]

Here are correct numbers:

Taycan:
94 pack has 87.4 usable = 93 % is usable

Polestar 2:
78 pack has 72.6 usable = 93.3% is usable

BMW i4 M50:
83.9 pack has 81.5 usable = 97.1% is usable

Model 3 LR/P old models (not in production any more):
80 pack has 72.6 usable = 90.75% is usable

Model 3 LR/P new models:
82 pack has 76.5 usable = 92.29% is usable


The article there claims that Model 3 and Polestar 2 uses 100% of the battery, but it's simply not so.
Now remember that all these cars here they have (exceptfor the BMW) about the same % of usable capacity..

BUT: what we dont know is chemistry and how different chemistry works with different capacity.
Also we dont know how much of this "non usable" capacity is brick protection?

Remember that while you can see here in theory that you can only use 93% of the Taycan 94 pack, it still has brick protection. Maybe 5% at least? I guess... So then if you charge to 100%, maybe you are at 98% or so..

So I would not charge past 90% for daily use, maybe down to 80%. Never charge to 100% and park, unless you drive a car with LFP batteries.. But normal batteries, dont charge to 100% a lot and never be long on 100%.

 

[SHM]

That's a really good point that I didn't really think about. Over time the battery will inevitably degrade in it's ability to reach "100% capacity" so perhaps the buffer helps guard against that...? Otherwise Taycans would have an additional 10% more range (equating to roughly 25-30 more miles from new).

It doesent work like this.
You must add the usable capacity together with the brick protection.
The brick protection is "always charged up", it is not unused capacity at top!

So if the brick protection is 5% (I just made this up, but guess it would not be far off) and usable is 87.4 of 94:
(87.4/94)*100+<brick protection>

lets just say it is 5% (we dont know): 93+5 = 98%.
So that means: when car show 100%, you have 98%.

Now in theory Porsche can "mask" range loss by freeing up the 2% on top. And that is of course possible to do, but 2% is "nothing". So lets say the car does 400km, what is 2% on 400km? It is 408 Km... So not a lot... I dont think they will do this either, as it will just give more warranty repairs and quicker range loss for customers charging to 100%.

What is interesting though is that Porsche says you dont have 87.4 usable, they say it is 83.7 kWh.
So what happends as the battery ages and you want to use your battery warranty? They can say: hey, it didnt decreas that much from 83.7 kWh.. (in reality it was 87.4, but tech sheet says 83.7).

 

[nickmdp]

Here are correct numbers:

Taycan:
94 pack has 87.4 usable = 93 % is usable

Polestar 2:
78 pack has 72.6 usable = 93.3% is usable

BMW i4 M50:
83.9 pack has 81.5 usable = 97.1% is usable

Model 3 LR/P old models (not in production any more):
80 pack has 72.6 usable = 90.75% is usable

Model 3 LR/P new models:
82 pack has 76.5 usable = 92.29% is usable

Got any sources for those numbers? None of those seem to match up with ev-database.org, and it's pretty widely reported as a 83.4 usable for the Taycan in every publication I could find, with nothing supporting the 87.4 number.

 

[Bognar67]

Got any sources for those numbers? None of those seem to match up with ev-database.org, and it's pretty widely reported as a 83.4 usable for the Taycan in every publication I could find, with nothing supporting the 87.4 number.

Taycan's net capacity is exactly 83,7kWh officially. Brutto is 93,4kWh. So 89,6% usable. All others are only speculation.

 

[nickmdp]

Taycan's net capacity is exactly 83,7kWh officially. Brutto is 93,4kWh. So 89,6% usable. All others are only speculation.

Ah, yeah, I typo'd the 83.7 to 83.4. Anyways, that does seem to be a larger buffer than other manufacturers at this point. Should be interesting if in a few years they decide that they can get by with a smaller buffer and up the range for everyone.

 

[caslca]

83.7 indeed for the 93.4 performance option. That is 90% usable capacity. It is interesting that the recommended 80% charge point would in fact put it at 72% absolute capacity which also makes quite a difference to the chemistry.

BTW, the source for 83.7KWh is Porsche (https://www.porsche.com/international/models/taycan/taycan-models/taycan-turbo/) :

 

[Bognar67]

Ah, yeah, I typo'd the 83.7 to 83.4. Anyways, that does seem to be a larger buffer than other manufacturers at this point. Should be interesting if in a few years they decide that they can get by with a smaller buffer and up the range for everyone.

Sure, just wanted confirm your numbers.

 

[Bognar67]

83.7 indeed for the 93.4 performance option. That is 90% usable capacity. It is interesting that the recommended 80% charge point would in fact put it at 72% absolute capacity which also makes quite a difference to the chemistry.

BTW, the source for 83.7KWh is Porsche (https://www.porsche.com/international/models/taycan/taycan-models/taycan-turbo/) :

80% seems very-very safety recommendation from Porsche. Tesla proposes 90% max for daily use, although have significantly less reserve. Still have marginal degradation according to the fleet stats.
On the other hand that 10% reserve is not only on the top, has some at the bottom as well. The ratio is not known. So it is higher than 72% for sure.

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