One more time: 85% Charging

[W1NGE]

It seems the % only works as a cap in the default profile?
all additional profiles it’s a minimum?

The only visible difference between the two is the geolocation feature to auto select (it works reliably) but the other settings appear on the surface to be the same and should function the same.

Sponsored

 

[Raphie]

The only visible difference between the two is the geolocation feature to auto select (it works reliably) but the other settings appear on the surface to be the same and should function the same.

That’s logic talking, but reality seems to be different, according to the screenshot?

 

[Sir]

That is (sadly) interesting - is your profile of type General or Location based (not that it's entirely relevant)?

Which EVSE are you using?

I have a suspicion that something may have been tweaked in the 2 years+ since launch that has slipped under the radar and as a consequence fuelling the confusion and therefore advice being given.

I feel the need to revert to a profile only charge and see what happens..I gave up on it in the early days as charging would never stop within the window given and so always charge to 100%.

Yes using the general profile with no location. My EVSE is quite old, a basic chargemaster with no internal options so just using the car to set configuration. I followed a youtube video to get to this as had problems before getting what I wanted when using timers for home charging. I'll try it with a another profile and see if it is the same.

 

[W1NGE]

The only visible difference between the two is the geolocation feature to auto select (it works reliably) but the other settings appear on the surface to be the same and should function the same.

The features and options are the same but depending on how you have configured some options may not be visible.

 

[Dee]

It's interesting reading all the different ways to charge and keep it at a set SoC. I have mine just on a profile with an 80% minimum, optimized charging and NO timer. The car charges to 80% and then just stops and states it as fully charged (i leave it plugged in). No need for a timer at all!

But do you know why it stops at 80%?

Fun fact: if you add a timer for maximum of 85% (or a specific day or date) that will activate within the time period it's loading to your minimum of 80% it'll charge to 100% and you'll ask the forum why this stupid timer doesn't do what it supposed to do, right? ?

 

[whitex]

I'm so annoyed that people use the minimum as an maximum.
Still.

It's called a minimum for a reason.
In profile you set the minimum (25%).
In timer you set the maximum (85%).
It's really that simple.

Really simple would be like what Tesla has in terms of charging interface. My parents in their 70s figured it out instantly without ever reading a manual or going to forums.

 

[whitex]

It's interesting reading all the different ways to charge and keep it at a set SoC. I have mine just on a profile with an 80% minimum, optimized charging and NO timer. The car charges to 80% and then just stops and states it as fully charged (i leave it plugged in). No need for a timer at all!

THAT was my understanding from watching the tutorials. @W1NGE ’s car apparently works differently and would charge to 100 without a timer. Maybe it’s due to some other settings elsewhere? Sorry @Dee , even seasoned owners get confused how the charging on a Taycan works (or it really works differently on different cars), so simple it is not.

 

[DougFrisk]

I've been doing some reading about the issues of battery degradation, what causes it and what can be done to reduce it.

This U Michigan article is a decent read: Tips for extending the lifetime of lithium-ion batteries | University of Michigan News (umich.edu) it has the following helpful infographic.

There are two types of degradation that happen to lithium ion batteries, mechanical and chemical. The causes of degradation comes down to combinations of battery temperature, battery charge state, and battery charge rate, all over time.

The batteries work by shuttling lithium ions from the cathode to the anode and back. When they're moving from the cathode to the anode it's discharging and going the other direction it's charging.

The goal is the lithium ions move into the electrodes (cathode and anode are electrodes that have a specific charge) and fill them somewhat like a sponge. This is where high states of charge and low states of charge can cause mechanical damage. At 100% charge, the cathode is full to bursting and at 0% charge the anode is. This can cause the material making up the electrodes to be physically damaged reducing the amount of lithium they can hold. Heat can increase the amount of damage done.

Over-voltage and over-amperage during charging can cause the same sort of issues. Think of the cathode as a plane during boarding or a stadium with people filing in before an event. When they are empty you can move people in fairly quickly, as it fills the number of new people that can enter per minute goes down. If you try to force them in faster they're going to start bumping into things and potentially causing damage. Temperature impacts this too, moving the ions from the anode to the cathode is a physical chemical process. Cold slows down the process and trying to charge faster than the chemistry can happen damages the battery. Too much heat can also cause damage. 270KW charging requires sort of Goldilocks conditions not too hot, not too cold, not too empty and not too full. But even when the conditions are perfect minor damage is occurring.

You can't get over-voltage during discharge, but you can get excessive current. 761 horsepower is 567KW. that's what the Turbo S is drawing from the battery momentarily during launch control acceleration. Is it causing degradation. Yes. Is it worth it? Yes.

Just in general, at higher temperatures the lithium can start to bind to other things in the battery like the casing or the material between the cathode and anode degrading capacity.

The nice thing is, the car does an excellent job of managing most of these issues itself. It keeps the battery temperature in a comfortable range and it controls the rate of charging/discharging. It even hides the true 100% and 0% charge states preventing the worst case charge state scenarios.

The practical upshot for us as owners is that the battery is happiest when it's not too empty and not too full. The rate of degradation between 20% and 80% state of charge is low, but then is starts to shoot up rapidly below 20% or above 80%. I assume 50% is the sweet spot because that's what Porsche recommends for long term storage. If you wanted to do the battery longevity equivalent of hypermiling you'd work out your typical daily consumption and charge every day with the intent of keeping it as close to 50% as possible over the course of your typical day while storing it in a cool location when not in use. Ten 45% - 55% -45% charge discharge cycles is not the same as one 0% - 100% - 0% cycle. The degradation from the ten smaller cycles is significantly less.

There's no need to be obsessive about it, it's a car, a tool, that will eventually wear out, but it's easy enough to avoid intentionally creating scenarios where the battery degrades. At least if you have at home charging that is.

Perhaps at some point Porsche can create an Inno-charge feature that monitors usage and charging habits and adjusts the target charge state based on typical daily usage.

(Sorry about the long post, I spend 25 years as a technical trainer and my job was to learn the technical stuff then communicate it to non-technical people. Thats why I tried to handwave it without using phrases like redox reaction, electrostatic repulsion, or electrolyte while still keeping it reasonably accurate.)

 

[Archimedes]

You can absolutely set up a profile that charges to 85% and stops there, without setting a departure timer.

 

[whitex]

Fun fact: if you add a timer for maximum of 85% (or a specific day or date) that will activate within the time period it's loading to your minimum of 80% it'll charge to 100% and you'll ask the forum why this stupid timer doesn't do what it supposed to do, right? ?

I think it's clear as mud.

 

[Raphie]

So, tonight my car is still on 98% and my wife will be charging her car.
tomorrow i’ll drive a 150km and will have the opportunity to top up at night.
At the risk of keeping going round in circles, it‘s still unclear to me and I see conflicting responses:

will charging stop (and remain stopped) at 85% when NOT using timers and only use the default program by just setting it’s MINIMUM CHARGE to 85% and ACTIVATING that profile?

 

[Archimedes]

So, tonight my car is still on 98% and my wife will be charging her car.
tomorrow i’ll drive a 150km and will have the opportunity to top up at night.
At the risk of keeping going round in circles, it‘s still unclear to me and I see conflicting responses:

will charging stop (and remain stopped) at 85% when NOT using timers and only use the default program by just setting it’s MINIMUM CHARGE to 85% and ACTIVATING that profile?

Go into the app, select charging under the details/functions tab. Add a home profile, set it to 85%, select optimized charging. Make that your active profile. It will charge to 85 percent and then stop.

I’d you ever want 100 percent, just switch to direct charging.

 

[Raphie]

Go into the app, select charging under the details/functions tab. Add a home profile, set it to 85%, select optimized charging. Make that your active profile. It will charge to 85 percent and then stop.

I’d you ever want 100 percent, just switch to direct charging.

This is what I had last night and it charged 100% regardless,

 

[Archimedes]

This is what I had last night and it charged 100% regardless,

I don’t know what that is, as my MyPorsche app looks totally different.

 

[WasserGKuehlt]

This is what I had last night and it charged 100% regardless,

This is strange. I'd check the status of "direct charging" in the car - it's possible that the app and the vehicle are out of sync. As others have said, based on the above the car should have stopped charging at 85%.

Sponsored