LEAF+ press release

My Nissan Leaf Forum

Help Support My Nissan Leaf Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
alozzy said:
Another factor, which should mean less degradation with the 62 kWh pack, is the typical depth of discharge (DoD).

For most people, the extra capacity will mean that they will very seldom discharge the pack by more than 20% - 25% between charging cycles. That translates to many more charging cycles over the life of the battery pack as compared to a 24 kWh pack where the DoD is much higher.

See this article, and table 2 in particular, for the correlation between DoD and the number of cycles over the life of the pack:

https://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries
This data is for temperature controlled cycling, so it applies to a larger pack with TMS.
 
alozzy said:
Another factor, which should mean less degradation with the 62 kWh pack, is the typical depth of discharge (DoD).

For most people, the extra capacity will mean that they will very seldom discharge the pack by more than 20% - 25% between charging cycles. That translates to many more charging cycles over the life of the battery pack as compared to a 24 kWh pack where the DoD is much higher.

See this article, and table 2 in particular, for the correlation between DoD and the number of cycles over the life of the pack:

https://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries

I agree. With a larger battery, the DEGREE of discharge range will be less than the making of "full charge/ discharge cycles" of a smaller battery. The smaller pack is worn out faster than the large. The larger battery will in essence be "at rest" most of the time and the charging cycles will not have perceptible effects on the chemistry health of the battery..
 
SageBrush said:
This data is for temperature controlled cycling, so it applies to a larger pack with TMS.

TMS doesn't mean the same thing as temperature controlled cycling.

Put a battery in a thermal chamber set to 25C...and the case of the battery might be at 25C +- 1C. But real cars do not and can not keep the temperature at a constant 25C. For example, Telsa Model S BMS seems to start cooling to limit temperature at 45C.

https://www.teslarati.com/watch-tesla-battery-thermal-management-action-supercharging/

My LEAF's battery, even on a summer trip with multiple QCs, has not gotten close to 45C. At best a TMS would only add weight, reduce reliability... about the only good thing about a TMS would be that power draw would be minimal locally. Because it would never turn on.

Yes, I know it is different in Arizona.
 
WetEV said:
Yes, I know it is different in Arizona.
And just about everywhere else outside the PNW in the USA. It's the 'everywhere else' part you are still struggling with.
 
palmermd said:
the plus cars [are] a nice improvement, but depending on the price may not do much. The way I see it, it is the car that we expected Nissan to make at this point and for about the price they are selling the non plus for. They really cant put a big price differential between them or they just wont sell. So either very little price difference and all sales go to the plus or they lower the price of the non plus cars. That might be a big win for Nissan.
This is essentially the way I see it. Having just bought a 2018, I hope they don’t lower the price that much for the non-plussed ;)
 
I would not be surprised to see the 40 KWhr Leaf discontinued - IMHO offering 3 versions of the 40 and 62 KWhr Leafs with overlapping pricing makes no sense. At a minimum I would expect the 40 KWhr SV and SL to be discontinued - maybe we will see a fire sale on the 40s?
 
joeriv said:
I would not be surprised to see the 40 KWhr Leaf discontinued - IMHO offering 3 versions of the 40 and 62 KWhr Leafs with overlapping pricing makes no sense. At a minimum I would expect the 40 KWhr SV and SL to be discontinued - maybe we will see a fire sale on the 40s?
On the Japanese website, they don’t have the S available in 62 kWh. That’s the only difference I could tell, for that region anyway.
 
joeriv said:
I would not be surprised to see the 40 KWhr Leaf discontinued - IMHO offering 3 versions of the 40 and 62 KWhr Leafs with overlapping pricing makes no sense. At a minimum I would expect the 40 KWhr SV and SL to be discontinued - maybe we will see a fire sale on the 40s?

well anything is possible but the press release along with several other statements from Nissan all but guarantee that 40 kwh will still be offered as is.
 
It's my understanding that even though it may cost Nissan more to be able to manufacture both 40 / 62 kWh variants, it's offset by the fact that they could sell more volume overall having both options. The 40 kWh "value" option is sufficient for the majority of less than 50 mile commuters, while the 62 kWh can cover everyone else who needs the range. It seems the EV manufacturers out there would be wise (and most are like Hyundai, etc_ to offer different range options to capture as many customers.
 
LEAF buyers are incredibly price sensitive, with range and technology being of lesser importance. The LEAF S 40kWh is Nissan's biggest seller, so it will be around until the COGS for a 62kWh version is at parity with the 40kWh variant.
 
WetEV said:
My LEAF's battery, even on a summer trip with multiple QCs, has not gotten close to 45C. At best a TMS would only add weight, reduce reliability... about the only good thing about a TMS would be that power draw would be minimal locally. Because it would never turn on.
Where are you taking summer trips and doing a QC(or multiple QCs) and not getting close to 45*C? 113*F is a temperature I've seen a number of times without doing a QC that day. I did 2 QCs yesterday, drove 180 miles and the battery was just above 90*F. It was in the mid 20*F range yesterday.
I put 250 miles on the car one day last year and had 2 short QCs... The battery was 124*F and even after cooling off overnight was still 80*F in the morning. How would a TMS reduce reliability? Have you heard a single TMS issue with Chevy EVs? Tesla? Fiat? BMW? How about early battery degradation with their cars?
A 62kWh battery is less likely to need a QC in the first place(longer range) and have a lower current draw per cell to produce the same overall output so it will likely stay cooler than a 24,30 or 40kWh pack, but it's still a shitty idea to not have TMS. In the winter you can keep the pack at a more efficient temperature (I see mine daily in the 40-50*F range... Even after charging for an hour and running heat for 30 minutes of that before I leave) during QC you can keep the pack under 100*F
 
Tsiah said:
How would a TMS reduce reliability? Have you heard a single TMS issue with Chevy EVs? Tesla? Fiat? BMW?
Actually for BMW, yes.

A quick search w/Facebook's crappy search (you need to an i3 group member) revealed these 4 folks (there might be more, since I didn't go digging further) had some AC failure that caused metal to be spewed into and contaminating the cooling lines. Several of these mentioned needing to replace the cooling lines/grid for the cells.

https://www.facebook.com/groups/BMWi3/permalink/2339028772837637/
https://www.facebook.com/groups/BMWi3/permalink/2407831862623994/
https://www.facebook.com/groups/BMWi3/permalink/1691928347547686/
https://www.facebook.com/groups/BMWi3/permalink/2056454037761780/?comment_id=2056598864413964&comment_tracking=%7B%22tn%22%3A%22R9%22%7D

In at least one case, the AC compressor was killed by metal fragments from something else that failed in the system.
 
Tsiah said:
I put 250 miles on the car one day last year and had 2 short QCs... The battery was 124*F and even after cooling off overnight was still 80*F in the morning. How would a TMS reduce reliability? Have you heard a single TMS issue with Chevy EVs? Tesla? Fiat? BMW? How about early battery degradation with their cars?

You live in Salt Lake City, about 10 C warmer than Seattle, and about 4 C warmer than Denver in July.

On the day that you drove 250 miles, your battery was about 6 C warmer than where a Tesla would start to cool the battery (45 C). That means you lost almost a day more battery life that day than you would have with a Tesla style TMS. Do that 3 times a year for 10 years, and your battery will get to 70% almost a whole month earlier.

Honda Fit EV doesn't have battery cooling, and has done well. Ford Focus Electric has done about as well as the LEAF, and has an extensive battery cooling system, and no DCQC capability.

Battery chemistry is complex. TMS sounds simple.

Like the old joke of a drunk looking for his lost keys under the street light. Not close where he lost them, but the light was better.


Tsiah said:
but it's still a shitty idea to not have TMS.

Why?

A TMS would never turn on for me. Why should I want one? A TMS isn't the difference that many seem to think it is. Most of the time, in most of the cars, failure of the battery cooling system wouldn't be noticeable as it would never attempt to turn on. Why should I pay to have one?
 
WetEV said:
Ford Focus Electric has done about as well as the LEAF, and has an extensive battery cooling system, and no DCQC capability.
Actually, the 2017s and 2018s added DCQC along with a larger battery for 100+ mile range. I'm a previous 2015 FFE owner. I did notice degradation after 3 years of ownership in TX. It didn't have an app like leafspy so I couldn't objectively compare and I also had different tires.
 
cwerdna said:
some AC failure that caused metal to be spewed into and contaminating the cooling lines. Several of these mentioned needing to replace the cooling lines/grid for the cells.

In at least one case, the AC compressor was killed by metal fragments from something else that failed in the system.
I'm a bit under informed then, I didn't know they used the AC system to cool the pack. That doesn't seem like a good idea.
 
WetEV said:
Why?

A TMS would never turn on for me. Why should I want one? A TMS isn't the difference that many seem to think it is. Most of the time, in most of the cars, failure of the battery cooling system wouldn't be noticeable as it would never attempt to turn on. Why should I pay to have one?
With such a large pack there are more places it will struggle to keep cool on longer trips, especially with 100+kW charging if we ever see it.
Maybe more of it is the size of the pack or chemistry vs having the TMS, but I don't see any 8 year old Leafs with 90% capacity. Then again 10% loss hurts a lot more when your range was barely 100 miles to begin with. If you start 250 miles of range, 225 miles still looks pretty good.
 
What is interesting, Hyundai Ioniq EV beats Leaf badly on highway and about the same in city driving. So we have 28kWh battery vs. 40 kWh. The reason - very low drag. Despite the fact Ioniq has smaller battery and very limited/primitive battery temperature management it works better in freezing temperatures and charges faster. It is not even 1-to-1 ratio. Ionic EV battery SOC level was significantly above Nissan Leaf battery throughout the entire trip. And despite the fact Ioniq is very aerodynamic the rear seats comfort was comparable to Leaf. For reference, Tesla Model 3 has only a 1/3 of rear seat height of either car, which they commented on and more than once.

"New Nissan Leaf vs Hyundai Ioniq road trip" https://www.youtube.com/watch?v=Gj3MsS9M3dE

Looks like Hyundai Kona is quite efficient also and was above expectations on other trip: Kona vs. Tesla Model X https://www.youtube.com/watch?v=inAQNHKhcrA
 
Tsiah said:
cwerdna said:
some AC failure that caused metal to be spewed into and contaminating the cooling lines. Several of these mentioned needing to replace the cooling lines/grid for the cells.

In at least one case, the AC compressor was killed by metal fragments from something else that failed in the system.
I'm a bit under informed then, I didn't know they used the AC system to cool the pack. That doesn't seem like a good idea.

Is there another cooling system? Because if not AC you are back to LEAF "tech" (said a bit sarcastically)

Well, I guess you could use a radiator system (LEAF does have one)
 
DaveinOlyWA said:
Is there another cooling system? Because if not AC you are back to LEAF "tech" (said a bit sarcastically)

Well, I guess you could use a radiator system (LEAF does have one)
Tesla circulates coolant around their cells.
 
Back
Top