Preconditioning facts and myths.

Faults and Technical chat for the Jaguar I-Pace
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Hfdid
Posts: 25
Joined: Fri Jan 25, 2019 11:42 am
Location: U.K.

Preconditioning facts and myths.

Post by Hfdid » Fri Mar 15, 2019 10:11 am

On going through the forum I have found the following.

1. Preconditioning only kicks in when the car is 100% charged.
2. Preconditioning takes about 4 hours to optimise
3. Charging to 100% will lead to long term battery issues.

This would mean to precondition your car it would have to be fully charged 4 hours prior to your departure time.
Those that precondition on a regular basis will get short term range gain but long term battery issues.
Those who only charge up to 60- 80% cannot precondition

Please feel free to give a view on this and state if it is an opinion or a FACT.
If FACT basis please state your source.
Thanks.
SE Corris Grey, black wheels,black pack and oyster upholstery.


d111112
Posts: 88
Joined: Fri Sep 14, 2018 7:43 am
Location: Austria

Re: Preconditioning facts and myths.

Post by d111112 » Fri Mar 15, 2019 10:58 am

My experience: I think this is really the case. I tried to set preconditioning times and I do not charge the car to 100% during the week because the range is more than enough for my daily commute. SOC is usually between 80% and 40%. It starts to preheat the cabin and it is able to activate the charger and uses the energy from the charger but it seems not to precondition the battery. On timed preconditioning it kicks shortly before the set departure time (30 Min. !?, did not check it in detail).
I Pace EV400 S, fuji white, air susp, 18“/20“, 02/2019
IMC: S19A_19.07.2-312706 || Telematics: 14.2
... :arrow: Didi


RichT
Posts: 49
Joined: Tue May 15, 2018 4:41 pm
Location: United Kingdom

Re: Preconditioning facts and myths.

Post by RichT » Fri Mar 15, 2019 11:05 am

Regarding
>Those who only charge up to 60- 80% cannot precondition

That is my understanding (sorry no proof). Initially it annoyed me but after some thought I believe it is sensible
Unless you need "full range" you don't need the battery preconditioned - you would just be wasting
energy heating up the battery, which would then dissipate when the car is parked at the end of your journey.
That is certainly true for my commute of 17 miles each way.

And if an 80% charge limit was available I wouldn't want battery preconditioning to kick in when the charge reached 80%,

However there was an inference that the preconditioned battery heat would be used to heat the cabin at the start of the journey
which would make sense at 80% charge in the winter if it is true.


Chewy
Posts: 694
Joined: Tue Nov 06, 2018 5:46 pm
Location: UK

Re: Preconditioning facts and myths.

Post by Chewy » Fri Mar 15, 2019 11:15 am

d111112 wrote:
Fri Mar 15, 2019 10:58 am
My experience: I think this is really the case. I tried to set preconditioning times and I do not charge the car to 100% during the week because the range is more than enough for my daily commute. SOC is usually between 80% and 40%. It starts to preheat the cabin and it is able to activate the charger and uses the energy from the charger but it seems not to precondition the battery. On timed preconditioning it kicks shortly before the set departure time (30 Min. !?, did not check it in detail).
The manual suggests that as part of the charging process the battery will be heated/cooled as the battery is better charged at 20degC that when it is hot or cold. As such, if you are able to monitor the power flow to the car, you will find it is likely more than that explained just by charging losses.

It also says that if a departure time is set it will ensure that the battery is at the optimum temperature for the start of your journey to get the best performance. Cabin heating is also carried out if a departure time is set. As such, there is no way to set a departure time without the I-Pace trying to charge its battery to 100% SoC - AT PRESENT.

So the process of charging the battery will condition it. If you have a departure time set it will also ensure the battery is at the right temperature before your departure. Battery temperature conditioning is only carried out when plugged into an external power source.

Cabin heating can occur whether the car is plugged in or not.

As an example: If you have just returned home from a long journey, or you have been driving your car like a Jaguar deserves to be driven, when you plug your car in you will hear the fans running to cool the battery. This will also happen on CCS chargers as the higher charge level will heat the battery very quickly.

Our friends with the 2018 Nissan Leaf will see charge temperatures up to 60 degC for the battery. This clearly is a problem for the battery as charging at those temps is very bad. In fact, Nissan reduce the charge levels to as low as 14kW even on a Rapid Charger capable of 50kW Charging when the battery is hot. This is know in the Leaf circles as #Rapidgate.

Nissan say they have “solved” this issue with a software update. What they have done is allow the battery to get even hotter when charging so they can charge at a higher rate. Battery degradation on the Nissan Leaf has always been severe, this can only make it worse.
Caesium Blue S. 250mi range on 18” wheels in the Winter. Hoping for 300 miles range when it warms up.


DougTheMac
Posts: 177
Joined: Mon Sep 17, 2018 7:50 pm
Location: Suffolk UK

Re: Preconditioning facts and myths.

Post by DougTheMac » Fri Mar 15, 2019 7:32 pm

I’m also totally confused about the whole preconditioning/climate/departure time/preferred charging time business. I’ve been playing around with these parameters, and I have an energy meter which plots power consumption. Early days, and I’ve only charged to 100% once, but the main observation for this post is that once at 100%, with a departure time set for many hours later, the car did NOT take any more power from the charger until 30min before departure, when the climate kicked in, and the car took an initial 7kW, rapidly dropping to 3->1.5 kW. This is not what I expected. There did not seem to be any preconditioning of the battery, at least not before the 30min. It was several hours after the end of charge, so the battery would have cooled down, tho’ ambient around 10degC, so the battery may well have still been at around 15degC.
I will continue to monitor this as I put more miles/charge cycles on the car and will report further.
The other observation from the power plots is that if you “stop” charging before 100% (via the app - I don’t think there is another way?) then it displays “charging paused”, but continues to charge, in short bursts at 7kW for about a minute every 4-7 minutes (my meter only has a time resolution of 1 minute). This slowly takes the SoC up. (So, the only way to limit the charge to 80% is indeed to unplug the cable...)
I can’t imagine that this pulsed charging is good for the battery.
Has anyone else got a power meter like this, and observed similar behaviour?
HSE Silicon Silver Pano Air+AD Oyster ordered 23/9/18 for delivery 1 March 19


d111112
Posts: 88
Joined: Fri Sep 14, 2018 7:43 am
Location: Austria

Re: Preconditioning facts and myths.

Post by d111112 » Fri Mar 15, 2019 9:42 pm

Hi Chewy,

thanks for the detailed explanation and summarization of documentation. I'm sorry but I think it does not match to my observations. I received the car 2,5 weeks ago and therefore I did not have the chance to test multiple times and note down my real world results in a well structured way. It's possibly difficult to identify some things without some more details from JLR about the detailed functioning of preconditioning and associated features.

Hi DougTheMac,
DougTheMac wrote:
Fri Mar 15, 2019 7:32 pm
I’m also totally confused about the whole preconditioning/climate/departure time/preferred charging time business.
I'm a little bit lost, too. My current findings show that it is not working like the documentation describes it and Chewy summarized in his post.
DougTheMac wrote:
Fri Mar 15, 2019 7:32 pm
I’ve been playing around with these parameters, and I have an energy meter which plots power consumption. Early days, and I’ve only charged to 100% once, but the main observation for this post is that once at 100%, with a departure time set for many hours later, the car did NOT take any more power from the charger until 30min before departure, when the climate kicked in, and the car took an initial 7kW, rapidly dropping to 3->1.5 kW. This is not what I expected. There did not seem to be any preconditioning of the battery, at least not before the 30min. It was several hours after the end of charge, so the battery would have cooled down, tho’ ambient around 10degC, so the battery may well have still been at around 15degC.
This matches exactly my observation. Did this procedure also once and can report that it was exactly the same behaviour. I do not have a power meter for a detailed plot but I checked the kw/h sums on my wallbox/charger app and the car didn't consume any kw/h after charging stopped itself at 100% hours before, except ~30 minutes before the programmed departure time it started to consume power from the wallbox again. At my garage the car sits at current wheater condition at a temperature between 8 and 12 degrees. But this consumption was not for preconditioning of battery pack, I think this was just cabin heating (when cabin heating kicks in it charges the battery, too).

It is exactly the same when I programmed a planned departure for the next morning and used the Jaguar remote app "stop charging" button in the app (to keep the SOC e.g. at 60%). The car does not consume any energy over night, the wallbox keeps "activated" and prepared for charging. The car starts ~30 min. before the departure time but it seems not to start anything before and it does not consume energy before. Only at the point 30 min. before departure it consumes some kw juice from the wallbox and this seems just the energy for cabin heating and no preconditioning of battery in advance ((when cabin heating kicks in it charges the battery, too). It's confusing :roll:
DougTheMac wrote:
Fri Mar 15, 2019 7:32 pm
I will continue to monitor this as I put more miles/charge cycles on the car and will report further.
The other observation from the power plots is that if you “stop” charging before 100% (via the app - I don’t think there is another way?) then it displays “charging paused”, but continues to charge, in short bursts at 7kW for about a minute every 4-7 minutes (my meter only has a time resolution of 1 minute). This slowly takes the SoC up. (So, the only way to limit the charge to 80% is indeed to unplug the cable...)
I can’t imagine that this pulsed charging is good for the battery.
Has anyone else got a power meter like this, and observed similar behaviour?
I have no detailed monitoring but I am able to compare the sums logged by the wallbox. As far as I noticed from my last tests there is no consumptions when I hit the "stop charging" button in the Jaguar remote app (e.g. over night or even 2 days). I will have a closer look and check tomorrow. 2 hours ago I just charged to 71% and stopped with the "stop charging" button, I noted down the value of my kw/h counter on the wallbox app and will have a look at it tomorrow morning.
Last edited by d111112 on Fri Mar 15, 2019 10:18 pm, edited 1 time in total.
I Pace EV400 S, fuji white, air susp, 18“/20“, 02/2019
IMC: S19A_19.07.2-312706 || Telematics: 14.2
... :arrow: Didi


Chewy
Posts: 694
Joined: Tue Nov 06, 2018 5:46 pm
Location: UK

Re: Preconditioning facts and myths.

Post by Chewy » Fri Mar 15, 2019 10:02 pm

d111112 wrote:
Fri Mar 15, 2019 9:42 pm
Hi Chewy,

thanks for the detailed explanation and summarization of documentation. I'm sorry but I think it does not match to my observations. I received the car 2,5 weeks ago and therefore I did not have the chance to test multiple times and note down my real world results in a well structured way. It's possibly difficult to identify some things without some more details from JLR about the detailed functioning of preconditioning and associated features.

Hi DougTheMac,
DougTheMac wrote:
Fri Mar 15, 2019 7:32 pm
I’m also totally confused about the whole preconditioning/climate/departure time/preferred charging time business.
I'm a little bit lost, too. My current findings show that it is not working like the documentation describes it and Chewy summarized in his post.
DougTheMac wrote:
Fri Mar 15, 2019 7:32 pm
I’ve been playing around with these parameters, and I have an energy meter which plots power consumption. Early days, and I’ve only charged to 100% once, but the main observation for this post is that once at 100%, with a departure time set for many hours later, the car did NOT take any more power from the charger until 30min before departure, when the climate kicked in, and the car took an initial 7kW, rapidly dropping to 3->1.5 kW. This is not what I expected. There did not seem to be any preconditioning of the battery, at least not before the 30min. It was several hours after the end of charge, so the battery would have cooled down, tho’ ambient around 10degC, so the battery may well have still been at around 15degC.
This matches exactly my observation. Did this procedure also once and can report that it was exactly the same behaviour. I do not have a power meter for a detailed plot but I checked the kw/h sums on my wallbox/charger app and the car didn't consume any kw/h after charging stopped itself at 100% hours before, except ~30 minutes before the programmed departure time it started to consume power from the wallbox again. At my garage the car sits at current wheater condition at a temperature between 8 and 12 degrees. But this consumption was not for preconditioning of battery pack, I think this was just cabin heating.

It is exactly the same when I programmed a planned departure for the next morning and used the Jaguar remote app "stop charging" button in the app (to keep the SOC e.g. at 60%). The car does not consume any energy over night, the wallbox keeps "activated" and prepared for charging. The car starts ~30 min. before the departure time but it seems not to start anything before and it does not consume energy before. Only at the point 30 min. before departure it consumes some kw juice from the wallbox and this seems just the energy for cabin heating and nothing else. It's confusing :roll:
DougTheMac wrote:
Fri Mar 15, 2019 7:32 pm
I will continue to monitor this as I put more miles/charge cycles on the car and will report further.
The other observation from the power plots is that if you “stop” charging before 100% (via the app - I don’t think there is another way?) then it displays “charging paused”, but continues to charge, in short bursts at 7kW for about a minute every 4-7 minutes (my meter only has a time resolution of 1 minute). This slowly takes the SoC up. (So, the only way to limit the charge to 80% is indeed to unplug the cable...)
I can’t imagine that this pulsed charging is good for the battery.
Has anyone else got a power meter like this, and observed similar behaviour?
I have no detailed monitoring but I am able to compare the sums logged by the wallbox. As far as I noticed from my last tests there is no consumptions when I hit the "stop charging" button in the Jaguar remote app (e.g. over night or even 2 days). I will have a closer look and check tomorrow. 2 hours ago I just charged to 71% and stopped with the "stop charging" button, I noted down the value of my kw/h counter on the wallbox app and will have a look at it tomorrow morning.

I rather agree with what people are observing rather than the details written in the manual, which is what I based my comments on. In general, the software as implemented appears to bear no resemblance to what is actually happening.

I have no doubt that Jaguar has released the car to the market far too early such that they beat Audi and others,.

The software is a complete and utter mess.
Caesium Blue S. 250mi range on 18” wheels in the Winter. Hoping for 300 miles range when it warms up.


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