Preconditioning & charging planner

[Yves]

thats all ok. but i do not understand: „I DC charge to 70% and charge the car to 100% on AC, it is outside so if I do none of that my battery is very cold“
you go to a fastcharger, charge to 70% than drive home, park on the street and charge to 100% with AC? this would not make much sense.
anyways when you leave with 100%, use the charging planner, you will have a perfect battery temp for your next charging 3 hours later.
the point exactly is that this is very complicated and not very significant at the same time.
thats why porsche researched this for many years now und came to conclusions. oneof this conclusions must be that we get better results if the cars computer calculates whats most efficient.

Correct, the AC charging will keep the battery from loosing all the heat generated during the DC charge, it will not heat the battery, just slows the cooling …

I have 3 DC charge stations all very close to home, like one is at less then a mile out …
As you have seen I advised other people to skip this, I like to get 100% efficiency, others can ignore or adapt to it …

If all goes well I will do the trip to the south of France with the Macan in colder conditions and I can report back on my charging time.
2 years ago with the iX it was not that great, used Apple Maps / BMW nav and the iX had no manual pre heating so I ended up 1h45 minutes charging …
If I can keep it under 1 hour this time, I’ll be happy …

The BMW App gives Charging time 1h8min and 3 stops
The Porsche App gives 54min and 4 stops …

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[CHP]

so what ?


In any case, this assumption cannot be stated as such. This whole discussion is only about a few minutes more or less. But to prove this "scientifically," the following test setup would have to be chosen:

Departure at outside temperature X, with charge level Y, distance to charging station Z. (Must be the same for all tests) Once with Porsche Charging Planner, once without. And once with "sport plus" (preconditioning is ALWAYS "on" here).

This should be repeated 10 times. I would be very grateful to @Yves for conducting this experiment. Until then, I would be very happy if this unnecessary discussion would end.

The central question here, which nobody can answer reliably: Energy consumption of heating the battery versus gain in charging speed with a warm Battery.

My Porsche Guy told me that porsche decided that its not worth it.

I think the main point is to reduce trip duration under very specific circumstances. Porsche states
by the time you reach the charging station, the battery will be within the optimal temperature range, allowing you to charge at maximum speed.

Except:

1) Batteries perform best within a moderate temperature range. Extreme cold or heat slows the chemical reactions within the battery, which temporarily reduces its efficiency and available power.

From Porsche: In very cold Sport Plus mode, the battery might need more power than a cold battery can give, triggering a temporary power limit.


2) A cold battery will limit its charging rate to avoid damage, significantly increasing the time spent at a charging station.

From Porsche: Use the app to schedule preheating/precooling while plugged in to maximize range and cabin comfort.

3) Consistently operating a battery outside its ideal temperature range (e.g., fast charging when cold or overheating) can cause chemical stress and accelerate degradation over time.

From Porsche: Avoid parking in direct sunlight for prolonged periods in ambient temperatures over 30°C to maximize battery life.


So yes, Porsche is very well aware of certain circumstances where preconditioning before starting your trip may be beneficial. Yves kindly provided personal experience to reduce charging and trip duration time. This is what the forum is all about.

 

[Yves]

I think the main point is to reduce trip duration under very specific circumstances. Porsche states
by the time you reach the charging station, the battery will be within the optimal temperature range, allowing you to charge at maximum speed.

Except:

1) Batteries perform best within a moderate temperature range. Extreme cold or heat slows the chemical reactions within the battery, which temporarily reduces its efficiency and available power.

From Porsche: In very cold Sport Plus mode, the battery might need more power than a cold battery can give, triggering a temporary power limit.


2) A cold battery will limit its charging rate to avoid damage, significantly increasing the time spent at a charging station.

From Porsche: Use the app to schedule preheating/precooling while plugged in to maximize range and cabin comfort.

3) Consistently operating a battery outside its ideal temperature range (e.g., fast charging when cold or overheating) can cause chemical stress and accelerate degradation over time.

From Porsche: Avoid parking in direct sunlight for prolonged periods in ambient temperatures over 30°C to maximize battery life.


So yes, Porsche is very well aware of certain circumstances where preconditioning before starting your trip may be beneficial. Yves kindly provided personal experience to reduce charging and trip duration time. This is what the forum is all about.

Exactly and I’m even running the risk of degrading my battery, as DC charging a battery at less then ideal temperature will degrade battery health. So the key takeaway, make sure your battery is always pre conditioned, you charge faster and you put less strain on the battery, something we did not talk about but is important, and which I neglected / took not enough into consideration as an argument to always Pre heat / Cool the battery …

 

[TomekGnomek]

Exactly and I’m even running the risk of degrading my battery, as DC charging a battery at less then ideal temperature will degrade battery health.

I think this is a myth. Car handles DC charging very well in extreme conditions, when you fast charge it during a very hot summer day with the car standing under the sun it just lowers the charging speed so the battery does not overheat and this prevents degradation. I wouldn't worry about that.

 

[Yves]

I think this is a myth. Car handles DC charging very well in extreme conditions, when you fast charge it during a very hot summer day with the car standing under the sun it just lowers the charging speed so the battery does not overheat and this prevents degradation. I wouldn't worry about that.

It is much better with newer cars, but it still has an effect, it’s just that it is better managed, and one can debate if it is really a thing these days, I prefer to be on the safe side as my cars are private and would like to keep them for a very long time …
One example, Regen is severely limited in power when battery is cold, but you can fast charge at 130kw?!


Also, and that remains to be proven, LFP should be less susceptible to this kind of degradation …

 

[Petzi]

@Yves "One example, Regen is severely limited in power when battery is cold"
not my observation-to the contrary. where is this information coming from?

 

[Yves]

@Yves "One example, Regen is severely limited in power when battery is cold"
not my observation-to the contrary. where is this information coming from?

If I start to drive with a cold battery like 10C the frist kilometers / 5minutes or so I have zero regen … if the battery is warmer instant. I suspect a software implementation issue, because if I turn the regen on when you go off the accelerator, there is regen from the first meters under the same conditions …

 

[Petzi]

If I start to drive with a cold battery like 10C the frist kilometers / 5minutes or so I have zero regen … if the battery is warmer instant. I suspect a software implementation issue, because if I turn the regen on when you go off the accelerator, there is regen from the first meters under the same conditions …

ok. so no regen if its switched off and immediate regen when it is switched on?

 

[Yves]

ok. so no regen if its switched off and immediate regen when it is switched on?

Yes when using the brake pedal I always have immediate regen if battery is Warm, when cold it takes some time, but if I turn on auto regen, when I go off accelerator I have immediate regen. Now to be really specific, if I use the brake pedal with auto regen on, it will increase the regen, but not as strong as if I had a warm battery.
I should see if I can use it to the full indicate circle …
Anyway I think Porsche is very conservative, but what is strange that if you go to a DC charger you can get 130kw power, but regen seems limited (we cannot know how much because it is graphics only, on my iX I see the power in value as well …)

It begs the question, why can you charge 130kw with a cold battery, but regen seems limited …

 

[Petzi]

Yes when using the brake pedal I always have immediate regen if battery is Warm, when cold it takes some time, but if I turn on auto regen, when I go off accelerator I have immediate regen. Now to be really specific, if I use the brake pedal with auto regen on, it will increase the regen, but not as strong as if I had a warm battery.
I should see if I can use it to the full indicate circle …
Anyway I think Porsche is very conservative, but what is strange that if you go to a DC charger you can get 130kw power, but regen seems limited (we cannot know how much because it is graphics only, on my iX I see the power in value as well …)

It begs the question, why can you charge 130kw with a cold battery, but regen seems limited …

do why dont you turn it on?

 

[Yves]

do why dont you turn it on?

I love coasting and love to get my foot of the accelerator, it is the most efficient way to drive and have regen kicking in with the brake, I also make sure I stay in regen when using brake pedal… so now when it is cold I turn on auto regen for the first part off my drive …

 

[Awaz]

Yes, coasting is the most efficient way to drive, especially on fast roads/motorways, and I love it as the car seems to coast forever.
But "regen on” is better in congested urban areas in stop and go traffic.
At least that is my experience, and when I asked a Porsche techy, he also suggested this.

 

[sor]

As mentioned, I have observed this several times: coldish battery … slow charging curve, 25C or warmer fast charging every time …

Now I can imagine that if we see 15C in the display that this is an average … and so it could be that one part is colder like 10C and the car keeps that value to determine how fast it can charge. Unfortunately there is not really a good app for the Porsche battery stats that uses the OBD port. CarScanner is the closest thing, but it’s values are really bizar and you need to do conversions, to make sense of it, which makes me doubt it.

I do not agree that one fast charge at lower temps is proof that it works all the time, otherwise we would not have that discussion and I do agree with the remark of @TomekGnomek that cold batteries do behave erratically … hence I will keep on testing and if the result is better then what I’ve experienced until now, I will also report back, I’m a grown up and can take the flack for it.

I cannot see the battery temp Of the iX without my OBD dongle, but I have a feeling that it is less prone to lower temps, not freezing just lower temps … but that is just gut feeling not scientific in any way

Yeah and the iX is one I never had a problem with fast charging in winter without preconditioning either.

What I mean by “it only takes one” is in terms of a claim that preconditioning is required to get good charging speeds. Your only need to see it once to know that the car is capable of good charging without preconditioning. In the previous thread I was even called “ill informed” for claiming I have gotten good speeds without needing to precondition.

The central point in the discussion is not so much about whether bringing the battery to optimal temp will affect charging, it does and we can probably all agree on that. The point is whether a moderately suboptimal battery temperature is responsible for a 50% drop in charging speed. That seems implausible.

We can talk about the complexities of it all for fun…. At the end of the day I’m not trying to talk anyone into doing something one way or another.

The fact is that if you observe good results with preconditioning, that’s great and you should use it. Or maybe one just wants to use it as an insurance policy, great.

If I find that I get good charging speeds without needing to fuss with getting the car to precondition, I’ll probably stick to not doing that and being able to use my preferred nav. If there were just a simple “precondition” button handy, maybe I’d push that (like they later introduced on the iX).

It’s all fine, and the feature is there for a reason.

Now what would be interesting is if precondition actuallly kicked in a rebalance as well. So instead if just burning energy trying to warm or cool the battery it shuffled it around, balancing cells to prepare for a charge. I doubt Porsche is that advanced on the BMS but something like that could account for a smoothing of unpredictable results.

 

[Yves]

Yeah and the iX is one I never had a problem with fast charging in winter without preconditioning either.

What I mean by “it only takes one” is in terms of a claim that preconditioning is required to get good charging speeds. Your only need to see it once to know that the car is capable of good charging without preconditioning. In the previous thread I was even called “ill informed” for claiming I have gotten good speeds without needing to precondition.

The central point in the discussion is not so much about whether bringing the battery to optimal temp will affect charging, it does and we can probably all agree on that. The point is whether a moderately suboptimal battery temperature is responsible for a 50% drop in charging speed. That seems implausible.

We can talk about the complexities of it all for fun…. At the end of the day I’m not trying to talk anyone into doing something one way or another.

The fact is that if you observe good results with preconditioning, that’s great and you should use it. Or maybe one just wants to use it as an insurance policy, great.

If I find that I get good charging speeds without needing to fuss with getting the car to precondition, I’ll probably stick to not doing that and being able to use my preferred nav. If there were just a simple “precondition” button handy, maybe I’d push that (like they later introduced on the iX).

It’s all fine, and the feature is there for a reason.

Now what would be interesting is if precondition actuallly kicked in a rebalance as well. So instead if just burning energy trying to warm or cool the battery it shuffled it around, balancing cells to prepare for a charge. I doubt Porsche is that advanced on the BMS but something like that could account for a smoothing of unpredictable results.

Yeah the iX is less picky on temperature, I think we have a consensus that pre condition works and should be used when battery is below optimal maximum charging speed temp if you do not want to waste time.
Everybody is free to decide what‘s preferred, having the right info will make you take a decision one way or the other.

Rebalancing should only kick in when charging on AC once your battery reaches 90% and the car stays on AC for at least 6 hours … that is what I read somewhere on This forum. Rebalancing can never run when the car is being driven …

I would love to have a manual pre conditioning button as an extra option, it’s easy to be programmed in and distributed as an OTA update …

Just saw a range test between 7X and G9, they also charged the G9 with a cold battery it did 270kw , guess that is to be expected if you can charge at 520kw peak

 

[sor]

I have something to say about rebalancing, but I’m collecting a bit more information. I suspect there are some quirks that can be triggered with certain usage patterns that account for some charging issues people have posted. Nothing super surprising if you’ve followed Taycan forum info.

The reason I brought it up in context of preconditioning is because rebalancing can also be a fix for poor charging speeds. I don’t necessarily think the current implementation can rebalance a running vehicle, just an “it would be nice if” comment.

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