Why the LEAF Gen 2 and not the 220 miles Tesla Model 3?

[lorenfb]

Thank you! The rabid defending of no battery TMS in the Leaf by some people on here is completely illogical. Makes me think of young earthers.

OK. Please indicate how much range loss you're willing to accept on the Gen 1 Leaf's (24/30kWh) with TMS,
e.g. min 10%, actually 15 - 20%. Surely you have Nissan battery engineering data, range loss data, cost analysis',
and Leaf marketing data to corroborate your viewpoint? Remember, when utilizing a TMS function to maintain
a relatively stable battery temperature, the TMS needs to consume energy all the time the vehicle is operational
and during some times when it's not, i.e. the battery has a large thermal mass.

Waiting, and please no anecdotal data or guesses.

With all due respect I can tell from your response that engaging with you is a rabbit hole that will never end.

If you have spent any time on the forums you can tell that many people have suffered precipitous drops in range in their batteries, in some cases losing bars within the first year when the Leaf first came out. I don't have access to internal data from Nissan and neither do you. I'm satisfied reading the forums and gleaning from various posts and polls that the Leaf has had a substantial problem with this issue. If you came to another conclusion, so be it. I share this view with many on the forums.

Please provide data:

1. The effect of using TMS, i.e. the reduction in battery degradation and the range loss.
You do know that temperature is only one factor in battery degradation, and many Leaf owners
find that parameter secondary to other parameters affecting degradation, e.g. aging/battery cycling?
2. The added cost to each Leaf for using TMS.
3. The Leaf sales loss to Nissan the result of the added cost and the reduction in range using TMS.

Do you have that data, think not!

 

[EatsShootsandLeafs]

No, nor does anyone else! So to conjecture that Nissan should have added TMS to the Gen 1 without
having all the facts/data is naive. And even with hindsight, Nissan's decision may have been the same.

So since we don't have access to Nissan's data, we can't possibly question it and we have to accept that they made the right decision. Or, maybe they made the wrong one but it's not our place to question them as they have all the data.

 

[EatsShootsandLeafs]

OK. Please indicate how much range loss you're willing to accept on the Gen 1 Leaf's (24/30kWh) with TMS,
e.g. min 10%, actually 15 - 20%. Surely you have Nissan battery engineering data, range loss data, cost analysis',
and Leaf marketing data to corroborate your viewpoint? Remember, when utilizing a TMS function to maintain
a relatively stable battery temperature, the TMS needs to consume energy all the time the vehicle is operational
and during some times when it's not, i.e. the battery has a large thermal mass.

Waiting, and please no anecdotal data or guesses.

With all due respect I can tell from your response that engaging with you is a rabbit hole that will never end.

If you have spent any time on the forums you can tell that many people have suffered precipitous drops in range in their batteries, in some cases losing bars within the first year when the Leaf first came out. I don't have access to internal data from Nissan and neither do you. I'm satisfied reading the forums and gleaning from various posts and polls that the Leaf has had a substantial problem with this issue. If you came to another conclusion, so be it. I share this view with many on the forums.

Please provide data:

1. The effect of using TMS, i.e. the reduction in battery degradation and the range loss.
You do know that temperature is only one factor in battery degradation, and many Leaf owners
find that parameter secondary to other parameters affecting degradation, e.g. aging/battery cycling?
2. The added cost to each Leaf for using TMS.
3. The Leaf sales loss to Nissan the result of the added cost and the reduction in range using TMS.

Do you have that data, think not!

What you're getting at I think is that you likely agree TMS is expensive, but the Leaf is just not good enough a car to deserve it. That may be so and there may be truth to it, but people should at least appreciate that to date many leafs have suffered range loss much worse than competitive EVs and make their purchase choice accordingly.

 

[lorenfb]

No, nor does anyone else! So to conjecture that Nissan should have added TMS to the Gen 1 without
having all the facts/data is naive. And even with hindsight, Nissan's decision may have been the same.

So since we don't have access to Nissan's data, we can't possibly question it and we have to accept that they made the right decision. Or, maybe they made the wrong one but it's not our place to question them as they have all the data.

OK. So we can all speculate/guess, and that's the extent of it without data!

 

[internalaudit]

Because I can't help myself, I thought I'd look into this more.

Here is a nicely detailed write up from a guy with a 2015 Leaf. The 2015 Leaf has a supposedly better heat-resistant battery than the early models. In two years and 14k miles he has a 10% range reduction. http://www.wind-works.org/cms/index.php?id=84&tx_ttnews%5Btt_news%5D=4464&cHash=92313192ff5b7949bd2086ad0bbfc94d

He says "This isn’t out of line with what others have seen.".

As for Tesla, a big matrix here shows that the average model s has projected loss of 23 miles over 100k (10%), with an actual loss reported of just under 6% @ 66k combining all results.
https://www.teslacentral.com/worried-about-tesla-battery-degradation-its-23-miles-every-100000-driven

The tesla data is more reliable because it's a large pool of drivers.

I don't know if relative geography of leaf and tesla is the same, but I imagine it's similar.

One of the teslas after 60k miles had a range reduction from 265 to 264. Anybody think any leaf can do that? The worst, and this was a significant outlier, had a 10% reduction after 54k miles.

Does the Tesla data include battery degradation for battery packs that Tesla had replaced?

I have read a couple of comments over on TMC as well as additional information from a friend who has a Model S that Tesla proactively replaces components that it thinks may fail.

Maybe it's like the old Rolls Royce where there are very few customer complaints because RR fixes the issues and word doesn't go out about them?

I'm not biased for or against Tesla or Leaf but just want to make some informed decision making when it comes to buying a BEV, in late 2018 at the earliest.

 

[Oils4AsphaultOnly]

Please provide data:

1. The effect of using TMS, i.e. the reduction in battery degradation and the range loss.
You do know that temperature is only one factor in battery degradation, and many Leaf owners
find that parameter secondary to other parameters affecting degradation, e.g. aging/battery cycling?
2. The added cost to each Leaf for using TMS.
3. The Leaf sales loss to Nissan the result of the added cost and the reduction in range using TMS.

Do you have that data, think not!

Regardless of whether we have data supporting no-TMS as the root cause of the Leaf's battery degradation, it is indisputable that Leaf batteries degrade.

On top of that, we do have hard data showing that the leaf battery degrades the quickest in warmer climates (AZ, TX, etc) and less so in cooler climates (WA, UK, norway, etc):
http://www.electricvehiclewiki.com/Real_World_Battery_Capacity_Loss

Couple the 2 facts together and how can you NOT conclude that an active TMS would extend the _life_ of the battery?!

 

[SageBrush]

No, nor does anyone else! So to conjecture that Nissan should have added TMS to the Gen 1 without
having all the facts/data is naive. And even with hindsight, Nissan's decision may have been the same.

So since we don't have access to Nissan's data, we can't possibly question it and we have to accept that they made the right decision. Or, maybe they made the wrong one but it's not our place to question them as they have all the data.

OK. So we can all speculate/guess, and that's the extent of it without data!

Do you dispute this data ?
http://mynissanleaf.com/viewtopic.php?f=31&t=16516&start=120

I presume not, so either you are saying that the benefit of TMS was not worth the costs, or you are saying that the LEAF battery sucks for a different reason.

The latter contention is not worth debating. There is a mountain of basic and applied research and data showing the effect of temperature on battery life. The Nissan chemistry is not immune.

As for the trade-off argument, I can see your point for 2010 but most certainly not for today when Tesla is selling a 220 mile range EV with superior battery protection for $36k. And if you take the opposite tack, that Nissan can sell a 24 kWh, 84 mile range (when new!) EV for $20k, how many people want a car at $20k that is likely hobbled by 60k miles or significantly degraded within 2-3 years ?

 

[lorenfb]

So since we don't have access to Nissan's data, we can't possibly question it and we have to accept that they made the right decision. Or, maybe they made the wrong one but it's not our place to question them as they have all the data.

OK. So we can all speculate/guess, and that's the extent of it without data!

Do you dispute this data ?
http://mynissanleaf.com/viewtopic.php?f=31&t=16516&start=120

I presume not, so either you are saying that the benefit of TMS was not worth the costs, or you are saying that the LEAF battery sucks for a different reason.

The latter contention is not worth debating. There is a mountain of basic and applied research and data showing the effect of temperature on battery life. The Nissan chemistry is not immune.

As for the trade-off argument, I can see your point for 2010 but most certainly not for today when Tesla is selling a 220 mile range EV with superior battery protection for $36k. And if you take the opposite tack, that Nissan can sell a 24 kWh EV for $20k, how many people want a car at $20k that is likely hobbled by 60k miles ?

No, but how much less degradation would have occurred via TMS at the expense of range loss, i.e. efficiency
reduction via extra weight, extra energy use, and possible smaller battery because of the cooling structure
space needed and insulation materials. Besides, all the presented degradation data above can't be
attributed just to battery thermal problems.

We can probably converge on agreement sooner if we move to the Climate Control thread!

 

[Nubo]

Please provide data:

1. The effect of using TMS, i.e. the reduction in battery degradation and the range loss.
You do know that temperature is only one factor in battery degradation, and many Leaf owners
find that parameter secondary to other parameters affecting degradation, e.g. aging/battery cycling?
2. The added cost to each Leaf for using TMS.
3. The Leaf sales loss to Nissan the result of the added cost and the reduction in range using TMS.

Do you have that data, think not!

Regardless of whether we have data supporting no-TMS as the root cause of the Leaf's battery degradation, it is indisputable that Leaf batteries degrade.

On top of that, we do have hard data showing that the leaf battery degrades the quickest in warmer climates (AZ, TX, etc) and less so in cooler climates (WA, UK, norway, etc):
http://www.electricvehiclewiki.com/Real_World_Battery_Capacity_Loss

Couple the 2 facts together and how can you NOT conclude that an active TMS would extend the _life_ of the battery?!

It might, but the details are important. If the TMS only cools while driving and/or charging, then that leaves a much larger portion of time where the vehicle can still be heat-soaked from ambient temperatures, hot garages, or blistering parking lots. If, on the other hand, it's full-time active cooling, that represents a significant ongoing expenditure of energy 24x7. The sweet-spot of energy cost vs pack longevity vs use cases, might be a lot more complex than first appears.

 

[SageBrush]

Please provide data:

1. The effect of using TMS, i.e. the reduction in battery degradation and the range loss.
You do know that temperature is only one factor in battery degradation, and many Leaf owners
find that parameter secondary to other parameters affecting degradation, e.g. aging/battery cycling?
2. The added cost to each Leaf for using TMS.
3. The Leaf sales loss to Nissan the result of the added cost and the reduction in range using TMS.

Do you have that data, think not!

Regardless of whether we have data supporting no-TMS as the root cause of the Leaf's battery degradation, it is indisputable that Leaf batteries degrade.

On top of that, we do have hard data showing that the leaf battery degrades the quickest in warmer climates (AZ, TX, etc) and less so in cooler climates (WA, UK, norway, etc):
http://www.electricvehiclewiki.com/Real_World_Battery_Capacity_Loss

Couple the 2 facts together and how can you NOT conclude that an active TMS would extend the _life_ of the battery?!

It might, but the details are important. If the TMS only cools while driving and/or charging, then that leaves a much larger portion of time where the vehicle can still be heat-soaked from ambient temperatures, hot garages, or blistering parking lots. If, on the other hand, it's full-time active cooling, that represents a significant ongoing expenditure of energy 24x7. The sweet-spot of energy cost vs pack longevity vs use cases, might be a lot more complex than first appears.

How about: engage when the pack is too hot (or too cold)

 

[JasonA]

It might, but the details are important. If the TMS only cools while driving and/or charging, then that leaves a much larger portion of time where the vehicle can still be heat-soaked from ambient temperatures, hot garages, or blistering parking lots. If, on the other hand, it's full-time active cooling, that represents a significant ongoing expenditure of energy 24x7. The sweet-spot of energy cost vs pack longevity vs use cases, might be a lot more complex than first appears.

It's no different then the Rav4 pack/TMS system. Tesla decided that it was OK for it to be on ONLY during "READY" (driving,etc) or charging. Completely different mode of operation from its sibling the S.

And if you are driving during the hot summer and the pack is 40*c and turn off at night the pack will still stay that hot but THOSE cells don't have any issues do they? (my 2012 Leaf is getting a new FREE battery after dropping almost 38%) and the pack runs cooler then the Rav and DOESN'T HAVE CHAdeMO!!!

My Rav gets QC'd all the time on 50kw chargers and only has 3% degradation so how do you explain that?

I don't get people or their logic when they think the Leaf DOESN'T need a TMS system :lol:

I'd like to hear how they plan to keep batteries cool that are absorbing 40 to 50kw of energy (70 to 100kw with CHAdeMO 2.0) and still keep cool??? :roll:

And yes, it is the heat that kills this chemistry in the Leaf. If you didn't know that by now, stop arguing.

Start watching around 2:20 and educate yourselves.

https://youtu.be/pxP0Cu00sZs

 

[lorenfb]

Please provide data:

1. The effect of using TMS, i.e. the reduction in battery degradation and the range loss.
You do know that temperature is only one factor in battery degradation, and many Leaf owners
find that parameter secondary to other parameters affecting degradation, e.g. aging/battery cycling?
2. The added cost to each Leaf for using TMS.
3. The Leaf sales loss to Nissan the result of the added cost and the reduction in range using TMS.

Do you have that data, think not!

Regardless of whether we have data supporting no-TMS as the root cause of the Leaf's battery degradation, it is indisputable that Leaf batteries degrade.

On top of that, we do have hard data showing that the leaf battery degrades the quickest in warmer climates (AZ, TX, etc) and less so in cooler climates (WA, UK, norway, etc):
http://www.electricvehiclewiki.com/Real_World_Battery_Capacity_Loss

Couple the 2 facts together and how can you NOT conclude that an active TMS would extend the _life_ of the battery?!

It might, but the details are important. If the TMS only cools while driving and/or charging, then that leaves a much larger portion of time where the vehicle can still be heat-soaked from ambient temperatures, hot garages, or blistering parking lots. If, on the other hand, it's full-time active cooling, that represents a significant ongoing expenditure of energy 24x7. The sweet-spot of energy cost vs pack longevity vs use cases, might be a lot more complex than first appears.

Can't be explained any simpler that! But many will still naively conclude that the use of TMS has no trade-offs.

 

[lorenfb]

Regardless of whether we have data supporting no-TMS as the root cause of the Leaf's battery degradation, it is indisputable that Leaf batteries degrade.

On top of that, we do have hard data showing that the leaf battery degrades the quickest in warmer climates (AZ, TX, etc) and less so in cooler climates (WA, UK, norway, etc):
http://www.electricvehiclewiki.com/Real_World_Battery_Capacity_Loss

Couple the 2 facts together and how can you NOT conclude that an active TMS would extend the _life_ of the battery?!

It might, but the details are important. If the TMS only cools while driving and/or charging, then that leaves a much larger portion of time where the vehicle can still be heat-soaked from ambient temperatures, hot garages, or blistering parking lots. If, on the other hand, it's full-time active cooling, that represents a significant ongoing expenditure of energy 24x7. The sweet-spot of energy cost vs pack longevity vs use cases, might be a lot more complex than first appears.

How about: engage when the pack is too hot (or too cold)

Seems logical, but given the thermal mass of the battery, it's more effective and efficient to control the temperature
over a desired range than to attempt to reduce the temperature when it reaches near the extreme point.

 

[JasonA]

Having a heat soaked battery again is not a bad thing. Tesla shows and proves that! They run their cells warm/hot!

It's all about the chemistry and Nissan chooses to use a crappy one.

Plus you can't run passive air cooling on a large thermal mass and expect it to work if the air itself is also hot! :lol:

 

[Oils4AsphaultOnly]

Please provide data:

1. The effect of using TMS, i.e. the reduction in battery degradation and the range loss.
You do know that temperature is only one factor in battery degradation, and many Leaf owners
find that parameter secondary to other parameters affecting degradation, e.g. aging/battery cycling?
2. The added cost to each Leaf for using TMS.
3. The Leaf sales loss to Nissan the result of the added cost and the reduction in range using TMS.

Do you have that data, think not!

Regardless of whether we have data supporting no-TMS as the root cause of the Leaf's battery degradation, it is indisputable that Leaf batteries degrade.

On top of that, we do have hard data showing that the leaf battery degrades the quickest in warmer climates (AZ, TX, etc) and less so in cooler climates (WA, UK, norway, etc):
http://www.electricvehiclewiki.com/Real_World_Battery_Capacity_Loss

Couple the 2 facts together and how can you NOT conclude that an active TMS would extend the _life_ of the battery?!

It might, but the details are important. If the TMS only cools while driving and/or charging, then that leaves a much larger portion of time where the vehicle can still be heat-soaked from ambient temperatures, hot garages, or blistering parking lots. If, on the other hand, it's full-time active cooling, that represents a significant ongoing expenditure of energy 24x7. The sweet-spot of energy cost vs pack longevity vs use cases, might be a lot more complex than first appears.

"It might ..." ?!?!

Are you saying that an active TMS that cools (remember it's the heat that's killing the batteries) only during driving and charging (when there's an additional 2.5 - 5 KW's of heat (charging/regen/discharging efficiency losses) being added to the batteries ABOVE ambient temps won't make a difference towards extending the life of the battery?!

That's like claiming smoking doesn't cause lung cancer since there's also smog in the air. Although it's technically correct, removing the extra heat, much like removing smoking, WILL help.

 

[lorenfb]

Regardless of whether we have data supporting no-TMS as the root cause of the Leaf's battery degradation, it is indisputable that Leaf batteries degrade.

On top of that, we do have hard data showing that the leaf battery degrades the quickest in warmer climates (AZ, TX, etc) and less so in cooler climates (WA, UK, norway, etc):
http://www.electricvehiclewiki.com/Real_World_Battery_Capacity_Loss

Couple the 2 facts together and how can you NOT conclude that an active TMS would extend the _life_ of the battery?!

It might, but the details are important. If the TMS only cools while driving and/or charging, then that leaves a much larger portion of time where the vehicle can still be heat-soaked from ambient temperatures, hot garages, or blistering parking lots. If, on the other hand, it's full-time active cooling, that represents a significant ongoing expenditure of energy 24x7. The sweet-spot of energy cost vs pack longevity vs use cases, might be a lot more complex than first appears.

"It might ..." ?!?!

Are you saying that an active TMS that cools (remember it's the heat that's killing the batteries) only during driving and charging (when there's an additional 2.5 - 5 KW's of heat (charging/regen/discharging efficiency losses) being added to the batteries ABOVE ambient temps won't make a difference towards extending the life of the battery?!

That's like claiming smoking doesn't cause lung cancer since there's also smog in the air. Although it's technically correct, removing the extra heat, much like removing smoking, WILL help.

1. Actually under moderate driving conditions minimal battery temperature increases occur, .e.g. monitor
your battery while diving during a 60 - 70 deg day. No max accelerate from every stop light allowed.
2. The greatest battery temp increase while charging occurs while QCing and obviously is dependent on the
the length of time. I typically QC no longer than 12 - 15 minutes and see only about 3 - 4 deg C increase.
3. Re-gen has minimal effect on increasing battery temp.
4. The greatest battery temperature effect occurs from ambient conditions.

The above implies that TMS needs to be active not only during driving and charging, i.e. while being parked
and unattended too.

 

[Oils4AsphaultOnly]

"It might ..." ?!?!

Are you saying that an active TMS that cools (remember it's the heat that's killing the batteries) only during driving and charging (when there's an additional 2.5 - 5 KW's of heat (charging/regen/discharging efficiency losses) being added to the batteries ABOVE ambient temps won't make a difference towards extending the life of the battery?!

That's like claiming smoking doesn't cause lung cancer since there's also smog in the air. Although it's technically correct, removing the extra heat, much like removing smoking, WILL help.

1. Actually under moderate driving conditions minimal battery temperature increases occur, .e.g. monitor
your battery while diving during a 60 - 70 deg day. No max accelerate from every stop light allowed.
2. The greatest battery temp increase while charging occurs while QCing and obviously is dependent on the
the length of time. I typically QC no longer than 12 - 15 minutes and see only about 3 - 4 deg C increase.
3. Re-gen has minimal effect on increasing battery temp.
4. The greatest battery temperature effect occurs from ambient conditions.

The above implies that TMS needs to be active not only during driving and charging, i.e. while being parked
and unattended too.

2. That's great for you! I recently QC'd for 30 mins in 90F ambient and saw a 34F increase (18C) to 123F (9 bars)! Since ambient was still 87F by the time I had parked for the night, my pack temp was still at 118F. It took over 10hrs until the following morning before the pack temp had reduced to 98.6F (still 7 bars).

IF there was a TMS set to cool while charging, then my pack would've spent many HOURS less time at elevated temperatures.

Keep in mind that your 4C increase was above ambient (and most likely during cooler weather too). And it was only for 12-15mins. A higher ambient, means higher peak temps during charging and driving, exactly the times that a TMS would be most effective. We're not looking to keep the battery cooler than ambient. We're trying to limit how far above ambient that the pack temp rises to.

 

[EatsShootsandLeafs]

OK. So we can all speculate/guess, and that's the extent of it without data!

Do you dispute this data ?
http://mynissanleaf.com/viewtopic.php?f=31&t=16516&start=120

I presume not, so either you are saying that the benefit of TMS was not worth the costs, or you are saying that the LEAF battery sucks for a different reason.

The latter contention is not worth debating. There is a mountain of basic and applied research and data showing the effect of temperature on battery life. The Nissan chemistry is not immune.

As for the trade-off argument, I can see your point for 2010 but most certainly not for today when Tesla is selling a 220 mile range EV with superior battery protection for $36k. And if you take the opposite tack, that Nissan can sell a 24 kWh EV for $20k, how many people want a car at $20k that is likely hobbled by 60k miles ?

No, but how much less degradation would have occurred via TMS at the expense of range loss, i.e. efficiency
reduction via extra weight, extra energy use, and possible smaller battery because of the cooling structure
space needed and insulation materials. Besides, all the presented degradation data above can't be
attributed just to battery thermal problems.

We can probably converge on agreement sooner if we move to the Climate Control thread!

Who knows. Maybe Nissan engineers are just too stupid to come out with an EV that doesn't suffer range loss at 5X (?) the rate of Tesla. I doubt they are, though. I think the company just made a financial decision to not bother. It sees the cars as throwaway EVs so that it can stay in the game and doesn't much car if somebody's range is down 30% after 60k miles.

I'm not even sure what you're arguing. Most people think lack of TMS is why batteries in Leaf suffer disproportionate range loss. Do you even deny this range loss is a thing?

 

[EatsShootsandLeafs]

Regardless of whether we have data supporting no-TMS as the root cause of the Leaf's battery degradation, it is indisputable that Leaf batteries degrade.

On top of that, we do have hard data showing that the leaf battery degrades the quickest in warmer climates (AZ, TX, etc) and less so in cooler climates (WA, UK, norway, etc):
http://www.electricvehiclewiki.com/Real_World_Battery_Capacity_Loss

Couple the 2 facts together and how can you NOT conclude that an active TMS would extend the _life_ of the battery?!

It might, but the details are important. If the TMS only cools while driving and/or charging, then that leaves a much larger portion of time where the vehicle can still be heat-soaked from ambient temperatures, hot garages, or blistering parking lots. If, on the other hand, it's full-time active cooling, that represents a significant ongoing expenditure of energy 24x7. The sweet-spot of energy cost vs pack longevity vs use cases, might be a lot more complex than first appears.

Can't be explained any simpler that! But many will still naively conclude that the use of TMS has no trade-offs.

lol who said this? I think you just like to argue. Nobody said that.

 

[GetOffYourGas]

Who knows. Maybe Nissan engineers are just too stupid to come out with an EV that doesn't suffer range loss at 5X (?) the rate of Tesla.

To play devil's advocate here...

The Leaf keeps getting compared to other EVs. Especially Tesla. But the smallest battery Tesla ever made was 2x the size of the largest battery Nissan made (60kWh versus 30kWh respectively). That means that Leafs have at least 2x the number of cycles to travel the same number of miles. On average, it's more like 3x the cycles.

I'm not saying that lack of TMS is not an issue. The Leaf certainly has trouble in hot climates. What I'm getting at is this: we don't know for sure how much of the degradation is due to temperature versus other factors.

Consider only cycle life. If Nissan's batteries are good for 1000 cycles, and the car goes 80 miles per charge, that's only 80k miles. If a Tesla is good for 1000 cycles and goes 200+ miles per charge, that's over 200k miles.

My Leaf is down to about 80% capacity after 45k miles and 5.5 years. If I started with a 40kWh battery rather than a 24kWh battery, would I still see 20% loss in this time? Maybe, maybe not.

Bottom line, I am happy with my Leaf and would be willing to take a risk on a new one. If you don't feel the same, perhaps a Tesla is better for you.