Battery temp management for new leaf

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Still nonsense. The oldest car on that graph is 4.5 years old with the vast majority being less than three years old. We all know from the LEAF that time and charging cycles play an enormous part in degradation. In fact, it's interesting that several Tesla's on that graph have lost more than 10% in the first couple of years.

BTW, that graph has been floating around for several months now. Wonder if they will ever update it. I kind of doubt it.
 
SageBrush said:
Joe6pack said:
That all appears to be an acceptable rate to you... for many others it is not. Tesla, for example, is projected to lose 20% in 25-30 years.

I will eat that Tesla battery if it's any good after 25-30 years. That's nonsense.

https://docs.google.com/spreadsheets/d/t024bMoRiDPIDialGnuKPsg/edit#gid=154312675
I would not care to extrapolate out to 25 years but clearly the Tesla battery in a BEV is in a class of its own for now.

Thanks for providing data to support my claim.

There is a flip side to this, though. There is supposedly another knee when you go far enough to the right. At some point, the batteries' performance just falls off a cliff. I don't pretend to know when this would happen (if it does at all), but like Joe I would be surprised if it didn't happen by 30 years. Not surprised enough to eat a battery, though...
 
Joe6pack said:
BTW, that graph has been floating around for several months now. Wonder if they will ever update it. I kind of doubt it.

"They" do not update anything. Users add their data and the graph on Google Docs shows all the data in the graph.
If you looked at Tesla sales since 2012 it would not surprise you to see the majority of data in the 3 year time frame.

For "fun," compare the user supplied LEAF battery capacity data. One bar is ~ 15% SoC loss for the 24 kWh battery; it may be much more for later 30 kWh models.

uc
 
And just where do these users get their data? To my knowledge no app like LeafSpy exists for a Tesla.
 
SageBrush said:
Joe6pack said:
And just where do these users get their data? To my knowledge no app like LeafSpy exists for a Tesla.
Your knowledge is sorely lacking

I think you have answered my question for me. This is a bunch of individual users running "range" tests on their own under different conditions with no controls. It isn't based on AHrs or any concrete reading from the BMS. In other words, it's anecdotal crap.
 
Joe6pack said:
SageBrush said:
Joe6pack said:
And just where do these users get their data? To my knowledge no app like LeafSpy exists for a Tesla.
Your knowledge is sorely lacking

I think you have answered my question for me. This is a bunch of individual users running "range" tests on their own under different conditions with no controls. It isn't based on AHrs or any concrete reading from the BMS. In other words, it's anecdotal crap.
No
 
SageBrush said:
Joe6pack said:
That all appears to be an acceptable rate to you... for many others it is not. Tesla, for example, is projected to lose 20% in 25-30 years.

I will eat that Tesla battery if it's any good after 25-30 years. That's nonsense.

https://docs.google.com/spreadsheets/d/t024bMoRiDPIDialGnuKPsg/edit#gid=154312675
I would not care to extrapolate out to 25 years but clearly the Tesla battery in a BEV is in a class of its own for now.

uc

I am confused as to which point the graph is supporting? The loss of 15% not acceptable to either the LEAF or Tesla? cause that is what the graph shows.

how about a graph that shows capacity degradation instead of the range an individual owner is getting. Can I say my 2013 LEAF with 8-10% loss had no degradation because I could still get 100% of its rated range?
 
DaveinOlyWA said:
I am confused as to which point the graph is supporting?
Look at the red line. It shows over time the best fit for the fraction of range when the car was new that remains.
For example:
If a Tesla started out with 300 miles of EPA range when new and lost 5% of range after 10 years, the 10 year old car would have a range of 285 miles and the car would be at 95%

A Tesla displays range as 'rated miles,' meaning the battery capacity divided by the EPA miles/kWh.
The owners are reporting the rated miles at a full battery charge and comparing to the range published by the EPA when the car was new.
In short, they have a kWh meter.
 
Where is the raw data? I'd like to see a linear regression through only the points from 600 days and/or 1000 days and up, although I'm doubtful of the usefulness of this with user-reported range (not based on a consistent, controlled protocol) instead of some internally measured parameters that would be more consistent from car to car.
 
BuckMkII said:
I'm doubtful of the usefulness of this with user-reported range (not based on a consistent, controlled protocol) instead of some internally measured parameters that would be more consistent from car to car.
The owners are reporting from a kWh meter equivalent and not a LEAF type GOM. Driving behavior and conditions do not affect the result. See my post above

If you like you can confirm this with the author of LeafSpy and TM-Spy Turbo3 although there really is not anything to doubt.
 
SageBrush said:
BuckMkII said:
I'm doubtful of the usefulness of this with user-reported range (not based on a consistent, controlled protocol) instead of some internally measured parameters that would be more consistent from car to car.
The owners are reporting from a kWh meter equivalent and not a LEAF type GOM. Driving behavior and conditions do not affect the result. See my post above

If you like you can confirm this with the author of LeafSpy and TM-Spy Turbo3 although there really is not anything to doubt.

Are you indicating that the graphical data previously posted results from TM-Spy app data? If I'm not mistaken,
that Tesla app is less than a year old in a released (non-beta) form, right?
 
lorenfb said:
Are you indicating that the graphical data previously posted results from TM-Spy app data?
No

I'm saying that TM-spy collaborates the car's rated miles (RM) display. As it obviously should since RM is simply kWh*K where K is a constant representing the EPA combined cycle consumption rate.
 
Can you folks take your endless, boring, off-topic comments to another thread?

Back on topic:

I saw no evidence at either of the LEAF intro events I attended of any change in temperature management in the "40 kWh" pack, and heard no hint of any changes planned for the "60 kWh" pack, when introduced.

So, both versions to have sealed packs with conductive cooling, just like all the earlier LEAFs?

Anyone seen or heard anything different?

edatoakrun said:
GetOffYourGas said:
DaveinOlyWA said:
With an expected increase in chademo speed as well. Hard to believe otherwise. The real question becomes can they do it all and keep the price down? Its my thinking that is the reason they have not already come out with it. They want to maintain that $30-35K price range or at least near that.
This is my thinking. But it's based more on hope and wishful thinking than any kind of hard facts.
It would have been an odd decision, IMO to add either liquid cooling or pack insulation to the 2018 LEAF.

Even more bizarre, would be to add it to only some of (the likely lower production volume, higher capacity pack versions) the 2019 LEAFs.

Adding either feature is relatively trivial from an engineering standpoint, though very expensive in terms of production cost and efficiency.

If Nissan saw any benefit, why did it not add either or both features to the 2018 MY?

So, while anything is possible, until a high integrity source reports otherwise, I think we should expect Nissan to retain passive thermal management, primarily utilizing conductive cooling, in all 2019 MY LEAFs.

Either or both pack designs could use suppplementary active air cooling, much as some other BEV manufactures have, which is very low cost, but provides minimal benefits in terms of reducing battery temperature.

I'd regard blowing air from the standard AC system over the cell cases as mainly a placebo for those suffering from capacity loss anxiety, but it would allow Nissan to tout this benefit, to those misinformed buyers for which it could be appealing.
 
SageBrush said:
lorenfb said:
Are you indicating that the graphical data previously posted results from TM-Spy app data?
No

I'm saying that TM-spy collaborates the car's rated miles (RM) display. As it obviously should since RM is simply kWh*K where K is a constant representing the EPA combined cycle consumption rate.

So what! It just reads the same BMS ECU data. As previously mentioned, without a controlled longitudinal study,
e.g. a linear regression, anecdotal data and resulting conclusions are of little value.
 
edatoakrun said:
Can you folks take your endless, boring, off-topic comments to another thread?

Back on topic:

I saw no evidence at either of the LEAF intro events I attended of any change in temperature management in the "40 kWh" pack, and heard no hint of any changes planned for the "60 kWh" pack, when introduced.

So, both versions to have sealed packs with conductive cooling, just like all the earlier LEAFs?

Anyone seen or heard anything different?

I have heard nothing official from Nissan. Plenty of speculation, though. I wouldn't be surprised if the former AESC will still produce the 60kWh battery, and not LG Chem. LG has a great battery, but it requires TMS. AESC has a less great battery (but still great IMO, all things considered) which doesn't require a TMS, at least in moderate climates. Yes this point is arguable, and has been argued ad nauseum. But the fact is, LG's battery is more volatile and would not survive anywhere near as well as AESC's without TMS.

Maybe Nissan needs another year because they are waiting on AESC to produce. Just more speculation, of course. But again, I have seen nothing more than a few journalists claiming that the 60kWh battery will be from LG, let alone that it will have TMS.
 
lorenfb said:
SageBrush said:
lorenfb said:
Are you indicating that the graphical data previously posted results from TM-Spy app data?
No

I'm saying that TM-spy collaborates the car's rated miles (RM) display. As it obviously should since RM is simply kWh*K where K is a constant representing the EPA combined cycle consumption rate.

So what! It just reads the same BMS ECU data.
Indeed it does. The data has the exact same utility had a large group of LEAF owners supplied their car Ahr battery capacities when charged to full in addition to the age of their cars and the odometer reading. Like this:

uc


The Tesla data however is on the internet in Google Doc format if you care to crunch it another way. I don't see the utility, but you could certainly collect all the cars that have provided more than one data point and display a "longitudinal" distribution of range loss per time or a longitudinal distribution of range loss per 10k miles. Regardless, the battery data as is says the Tesla has phenomenal longevity, while the Nissan battery ... pretty much sucks
 
SageBrush said:
The data is on the internet in Google Doc format if you care to crunch it another way. I don't see the utility, but you could certainly collect all the cars that have provided more than one data point and display a distribution of range loss per time. Regardless, the battery data as is says the Tesla has phenomenal longevity, while the Nissan battery ... pretty much sucks

What happens when the data are portioned into vehicles built 3/13 and earlier versus vehicles built 4/13 and later? I presume you would see the utility of doing that.
 
Dooglas said:
SageBrush said:
The data is on the internet in Google Doc format if you care to crunch it another way. I don't see the utility, but you could certainly collect all the cars that have provided more than one data point and display a distribution of range loss per time. Regardless, the battery data as is says the Tesla has phenomenal longevity, while the Nissan battery ... pretty much sucks

What happens when the data are portioned into vehicles built 3/13 and earlier versus vehicles built 4/13 and later?
The raw LEAF data (as shown in the post above) is not available for other types of analysis. My comment to Lorenfb was talking about the Tesla owner battery data available on the web in Google Doc.
 
So the Tesla data is the reading on the Tesla's GOM after a full charge at startup. That number is then compared to the theoretical EPA range of the car to derive the % degradation. This would be the same as taking the reading from the LEAF's GOM after a full charge and comparing that to its theoretical EPA range which we all know would be bogus. This is not the same thing as reading the remaining capacity in AHrs directly from the BMS. It also explains why so many cars have negative degradation.
 
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