8% range increase and 107kW charging imminent?

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Chewy
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Re: 8% range increase and 107kW charging imminent?

Post by Chewy » Sun Oct 13, 2019 9:21 pm

qqiao wrote:
Sun Oct 13, 2019 9:08 pm
One thing I might add to Chewy's explanation is that another reason to not turn off a PM motor is that they can't free roll anyway. The magnets are permanent, so rotating magnets in the rotors will inevitably generate a current in the stator coils.

Induction motors on the other hand, the magnetic field in the rotors are generated by induced current in the rotor coils, so if you switch off the stator coils, they are perfectly happy to free roll.

So in the case of the Tesla drive train, they can have the PM do the driving, and have the induction one just free roll.

In the i-Paces case, that is impossible, either you drive the PM motor, or it is regenerating.
Very good point.


SteveA
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Location: UK

Re: 8% range increase and 107kW charging imminent?

Post by SteveA » Sun Oct 13, 2019 9:23 pm

qqiao wrote:
Sun Oct 13, 2019 9:08 pm
One thing I might add to Chewy's explanation is that another reason to not turn off a PM motor is that they can't free roll anyway. The magnets are permanent, so rotating magnets in the rotors will inevitably generate current in the stator coils.

Induction motors on the other hand, the magnetic field in the rotors are generated by induced current in the rotor coils, so if you switch off the stator coils, they are perfectly happy to free roll.

So in the case of the Tesla drive train, they can have the PM do the driving, and have the induction one just free roll.

In the i-Paces case, that is impossible, either you drive the PM motor, or it is regenerating.
I understand the above but there is one thing that confuses me - If you either drive the PM motor, or its regenerating, what is happening when the car is in neutral, it feels like the car is coasting without power and without regen. So in neutral, are the motors disconnected from the drive train, and not turning?
I Pace EV400 SE, Yulong white, options: Oyster leather, 20' wheels, MY19, delivered 03/2019
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FENorway
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Re: 8% range increase and 107kW charging imminent?

Post by FENorway » Sun Oct 13, 2019 9:35 pm

qqiao wrote:
Sun Oct 13, 2019 9:08 pm
One thing I might add to Chewy's explanation is that another reason to not turn off a PM motor is that they can't free roll anyway
Have you tried to put an I-Pace in N?
FE Corris grey light oyster/light oyster Performance 22" 5069 & 18" 1022 19B_19.40.4-436082 and 14.2


Chewy
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Location: Forest of Dean. UK.

Re: 8% range increase and 107kW charging imminent?

Post by Chewy » Sun Oct 13, 2019 9:37 pm

SteveA wrote:
Sun Oct 13, 2019 9:23 pm
qqiao wrote:
Sun Oct 13, 2019 9:08 pm
One thing I might add to Chewy's explanation is that another reason to not turn off a PM motor is that they can't free roll anyway. The magnets are permanent, so rotating magnets in the rotors will inevitably generate current in the stator coils.

Induction motors on the other hand, the magnetic field in the rotors are generated by induced current in the rotor coils, so if you switch off the stator coils, they are perfectly happy to free roll.

So in the case of the Tesla drive train, they can have the PM do the driving, and have the induction one just free roll.

In the i-Paces case, that is impossible, either you drive the PM motor, or it is regenerating.
I understand the above but there is one thing that confuses me - If you either drive the PM motor, or its regenerating, what is happening when the car is in neutral, it feels like the car is coasting without power and without regen. So in neutral, are the motors disconnected from the drive train, and not turning?
The motors are permanently connected to the wheels via a fixed single speed gearbox. "NEUTRAL" is a hangover term from ICE cars. To "simulate" a neutral condition the I-Pace has to deliver power to the motors to cancel out the regen effect, unlike the Tesla. As such, running in Neutral in the I-Pace is just like finding the pedal position that gives a value of 0 on the power/regen indicator.


FENorway
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Re: 8% range increase and 107kW charging imminent?

Post by FENorway » Sun Oct 13, 2019 9:50 pm

Chewy wrote:
Sun Oct 13, 2019 9:37 pm
SteveA wrote:
Sun Oct 13, 2019 9:23 pm
qqiao wrote:
Sun Oct 13, 2019 9:08 pm
One thing I might add to Chewy's explanation is that another reason to not turn off a PM motor is that they can't free roll anyway. The magnets are permanent, so rotating magnets in the rotors will inevitably generate current in the stator coils.

Induction motors on the other hand, the magnetic field in the rotors are generated by induced current in the rotor coils, so if you switch off the stator coils, they are perfectly happy to free roll.

So in the case of the Tesla drive train, they can have the PM do the driving, and have the induction one just free roll.

In the i-Paces case, that is impossible, either you drive the PM motor, or it is regenerating.
I understand the above but there is one thing that confuses me - If you either drive the PM motor, or its regenerating, what is happening when the car is in neutral, it feels like the car is coasting without power and without regen. So in neutral, are the motors disconnected from the drive train, and not turning?
The motors are permanently connected to the wheels via a fixed single speed gearbox. "NEUTRAL" is a hangover term from ICE cars. To "simulate" a neutral condition the I-Pace has to deliver power to the motors to cancel out the regen effect, unlike the Tesla. As such, running in Neutral in the I-Pace is just like finding the pedal position that gives a value of 0 on the power/regen indicator.
Is this something you think or something you have read?
In N there is no regenerative brake available. Why not if the car is "balancing".?

And one of the engineers at Jaguar have confirmed that the I-Pace is 2WD below 30mph with little power demand. Then 1 motor is cut off.
FE Corris grey light oyster/light oyster Performance 22" 5069 & 18" 1022 19B_19.40.4-436082 and 14.2


Chewy
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Location: Forest of Dean. UK.

Re: 8% range increase and 107kW charging imminent?

Post by Chewy » Sun Oct 13, 2019 10:05 pm

FENorway wrote:
Sun Oct 13, 2019 9:50 pm
Chewy wrote:
Sun Oct 13, 2019 9:37 pm
SteveA wrote:
Sun Oct 13, 2019 9:23 pm


I understand the above but there is one thing that confuses me - If you either drive the PM motor, or its regenerating, what is happening when the car is in neutral, it feels like the car is coasting without power and without regen. So in neutral, are the motors disconnected from the drive train, and not turning?
The motors are permanently connected to the wheels via a fixed single speed gearbox. "NEUTRAL" is a hangover term from ICE cars. To "simulate" a neutral condition the I-Pace has to deliver power to the motors to cancel out the regen effect, unlike the Tesla. As such, running in Neutral in the I-Pace is just like finding the pedal position that gives a value of 0 on the power/regen indicator.
Is this something you think or something you have read?
In N there is no regenerative brake available. Why not if the car is "balancing".?
Sorry, don't quite understand your use of "balancing" allowing regen.

In what can be termed as "Neutral" in the I-Pace, the BMS can very quickly and easily produce a zero current equivalent at the drive. There is no clutch in an EV that engages and disengages at zero speed or "Neutral".

Think of it as just setting the regen to zero. The I-Pace will give almost no regen at 100% SoC to protect the battery. "Neutral" is just a zero regen state.


fa147
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Re: 8% range increase and 107kW charging imminent?

Post by fa147 » Sun Oct 13, 2019 10:11 pm

SteveA wrote:
Sun Oct 13, 2019 7:19 pm
SK1973 wrote:
Sun Oct 13, 2019 7:13 pm
Maybe a language issue, but I do not understand the following paragraph in the shared posting. Could someone pls help and explain what this is about and what the gain will be once the balancing algorithm is improved? What does ‚charge the charging cable‘ mean. Does the car stop charging too early? Thx
- To fully replenish the battery, the battery must be given the necessary time to balance the cells. You can 'lose' more kWh if you charge the charging cable too early even when the car reports to be full. Smarter balancing algorithms are being worked on to reduce this 'problem'.<br/>
This is correct, it is something that most electric car manufacturers work with and there will be ongoing optimizations via SOTA.<br/>
I assumed that was an error and should have said "remove the charging cable too early".
I'm slightly confused. If Jag "protect the top of the battery" then why would charging up to 100% make a difference as far as balancing the cells? Technically, it should not, correct? This is because 100% SoC as we see it is in fact more like 9x% SoC.
Help me understand.
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Chewy
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Joined: Tue Nov 06, 2018 5:46 pm
Location: Forest of Dean. UK.

Re: 8% range increase and 107kW charging imminent?

Post by Chewy » Sun Oct 13, 2019 11:02 pm

fa147 wrote:
Sun Oct 13, 2019 10:11 pm
SteveA wrote:
Sun Oct 13, 2019 7:19 pm
SK1973 wrote:
Sun Oct 13, 2019 7:13 pm
Maybe a language issue, but I do not understand the following paragraph in the shared posting. Could someone pls help and explain what this is about and what the gain will be once the balancing algorithm is improved? What does ‚charge the charging cable‘ mean. Does the car stop charging too early? Thx

I assumed that was an error and should have said "remove the charging cable too early".
I'm slightly confused. If Jag "protect the top of the battery" then why would charging up to 100% make a difference as far as balancing the cells? Technically, it should not, correct? This is because 100% SoC as we see it is in fact more like 9x% SoC.
Help me understand.
You are correct that the I-Pace battery does not charge fully to 100% SoC, it charges to an Indicated 100% SoC. We don't know exactly what level this is, but probably somewhere around 97%.

The "battery" in the I-Pace is composed of a number of "cells" that are connected in a combination of parallel and series. Each "cell", although fundamentally the same as all other cells in the battery, will charge at slightly different rates. This means that some of the cells will reach the 100% level before others. This is why "tapering" of the rate of charge occurs typically above 80%. As the "battery" gets closer to 100% SoC the BMS has to transfer charge levels between the "cells" to even them out and prevent an individual cell being overcharged. This balancing can be very time consuming and is best carried out at very low charge rates, hence better on your home charger where the rates drop much lower than with a Rapid Charger. That is one of the reasons why you should not charge to 100% SoC on a Rapid Charger unless you absolutely have to. Once you get above 80% SoC the advantage of a Rapid Charger is quickly removed.

So although the car may indicate 100% SoC, it still has a lot of work to do. Jaguar do not tell us in detail how the BMS manages the top end of the charge. However, I would suggest they don't let any single cell get above a real 97% SoC - which may be a 100% Indicated SoC. So as one cell reaches the maximum level, balancing must begin and charging levels will be extremely slow. It is likely that at this
condition the car will indicate that 100% SoC has been reached. If the battery is removed from the charger at this point, then it is likely that many of the cells will not be fully charged and the balancing will not have completed.

If you only ever charge to 80% SoC, then this balancing of the battery cells will not happen. However, I have never read any evidence that this is bad for the "battery". Effectively, each "cell" is a battery in it's own right and not charging it to 100% should not create a problem. It could be possible that over time if a weak cell is not allowed to charge to 100% indictated SoC then it will charge less and less each time which could lead to a failure of that cell in the pack - this would take a long time and may fall outside the warranty period. I will add that Jaguar have told me that they have data that shows it is better for the life of the battery to charge it to 100% SoC rather than 80% SoC.

I have pretty much always charged to 100% SoC using my home or work charger at 7kW overnight. As such, the cells have always been balanced after each charge. After 15,000 of driving I had lost 3% SoH. This 3% was spread evenly across each cell, suggesting even degradation of the cells. Some on the forum have reported very uneven degradation across the cells when they have had a SoH check, maybe this is due to more Rapid Charging of the battery and/or not allowing time for the cells to balance.

Cell Balancing on the 2018 Nissan Leaf....

20191013_232345.jpg

Last edited by Chewy on Mon Oct 14, 2019 12:21 am, edited 2 times in total.


emgf
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Location: Paris

Re: 8% range increase and 107kW charging imminent?

Post by emgf » Sun Oct 13, 2019 11:16 pm

kermit68 wrote:
Sat Oct 12, 2019 9:34 am
The charging rate improvement will not be negligible . Today your average rate is around 75KW and it will go up to 100 KW+ : a 30% increase and therefore a 30% time decrease
Based on Jaguar engineer statements on charging I see an improvement only below 10% SOC. But I may have not understood correctly what he was saying. Also, he clearly states that maximum theoretical charging speed is 107Kw and combining this with the tapering in charging speed that occurs at 60%, I can't see a real improvement on average charging speed. But as i said i may have missed some points.
I will get the upgrade later today and make some tests this week
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fa147
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Location: London / United Kingdom

Re: 8% range increase and 107kW charging imminent?

Post by fa147 » Mon Oct 14, 2019 2:42 am

Chewy wrote:
Sun Oct 13, 2019 11:02 pm
Thanks Chewy.
I-Pace MY20 HSE, Corris Grey, Ebony/Ebony Interior, 20” Grey & Diamond Turned, Panoramic Roof
IMC: S19B_19.40.4-436082 | Telematics: 16.2 | Map 8.30.100.156


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