Everything you might want to know about the '18 LEAF engineering

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LeftieBiker said:
Change "design flaw" to just "flaw" and it's an observation, not a conclusion. Mayne it is a manufacturing issue, for all the difference it seems to make. You can think of this as an 'occasional lemon' problem, but so far we have only one, AFAIK, person posting good numbers for a 30kh pack. The rest of the ones posted here show rapid degradation.

Sorry, BikerBoy, no offense, but I recommend you hold your fire and let that situation come to conclusion. You may find yourself barking up the wrong tree.
 
DaveinOlyWA said:
LeftieBiker said:
I didn't post any "conclusions." Why the variance in SOH among drivers in the same region? We don't know. The drivers don't know either, and they aren't doing anything that Nissan has warned them not to do. It may be heating related to charging, but we don't know that yet. The 30kwh packs have a serious design flaw that appears to be causing excess degradation in a majority of the cars. That is Nissan's fault, not the drivers' fault.


cars? cellphones? or any other device where we are required to manage the battery? It used to be simply low quality batteries. Not so much anymore.

The reality is we have traded battery longevity for convenience. We accept that unknowingly then blame whoever when our cellphones can't make it without a boost in the middle of the day 6 months down the line. But why? Because the battery used to go to bed at 60% before being recharged overnight to full for the next day .

We didn't understand the importance of avoiding 100% needlessly because it was simply much easier to plug it in at night and forget about it till morning. Way too much of a hassle to plug it in for an hour a few times a day.... WAY too much hassle.

I think Leftie's point here can't be over-emphasized. The behaviors you cite (without debating their harms or merits), are something Nissan does not recommend for, or against. If one cannot expect acceptable durability by using the vehicle in a convenient fashion, then it is incumbent upon Nissan to explain how to achieve that durability.

And yet they took away the one tool that could be used to reliably terminate charge before 100%. So outside of blatant abuse, I can't reasonably assign blame to everyday LEAF drivers.
 
Nubo said:
[The behaviors you cite (without debating their harms or merits), are something Nissan does not recommend for, or against. If one cannot expect acceptable durability by using the vehicle in a convenient fashion, then it is incumbent upon Nissan to explain how to achieve that durability.
Set a timer to finish charging shortly before use.

While most of Dave's pronouncements are the stuff of speculation from an anecdote or three, it just makes sense to not have the battery stew in the heat at high SOC.
 
SageBrush said:
10% degradation per 500 cycles. Environmental details were not mentioned
Ouch
Silver lining: at least this time around Nissan is being honest that the battery willl have poor longevity.

To put the cycles number in some different perspectives. Some Tesla-like battery numbers:

>>>>>>>>>>>>>>>>>>>>>
From the following article on batteries "similar" to what Tesla is using.

Divide those number of cycles by 365 or 300 or whatever number of days per year you want. Pretty long.

"500 cycles? But that’s (relatively) low! Yes. But what is not shown on the spec sheet is that when you partially charge and discharge, degradation of the battery capacity is reduced. Thus, you can do over
40 000 charge/discharge cycles when going from 30% to 70% only. Or over
35 000 charge/discharge cycles from 20% to 80%;
28 000 cycles from 10% to 90%;
15 000 cycles from 8% to 92%,
07 500 cylces from 6% to 94%, and the capacity reduction goes faster and faster, finally reaching
00 500 cycles when recharging from 0% to 100%."

http://blog.evandmore.com/lets-talk-about-the-panasonic-ncr18650b/
<<<<<<<<<<<<<<<<<<<<<
 
scottf200 said:
SageBrush said:
10% degradation per 500 cycles. Environmental details were not mentioned
Ouch
Silver lining: at least this time around Nissan is being honest that the battery willl have poor longevity.

To put the cycles number in some different perspectives. Some Tesla-like battery numbers:

>>>>>>>>>>>>>>>>>>>>>
From the following article on batteries "similar" to what Tesla is using.

Divide those number of cycles by 365 or 300 or whatever number of days per year you want. Pretty long.

"500 cycles? But that’s (relatively) low! Yes. But what is not shown on the spec sheet is that when you partially charge and discharge, degradation of the battery capacity is reduced. Thus, you can do over
40 000 charge/discharge cycles when going from 30% to 70% only. Or over
35 000 charge/discharge cycles from 20% to 80%;
28 000 cycles from 10% to 90%;
15 000 cycles from 8% to 92%,
07 500 cylces from 6% to 94%, and the capacity reduction goes faster and faster, finally reaching
00 500 cycles when recharging from 0% to 100%."

http://blog.evandmore.com/lets-talk-about-the-panasonic-ncr18650b/
<<<<<<<<<<<<<<<<<<<<<

You are right that DoD affects battery longevity but you cannot just perform simple division from the test data to infer how long the battery will last in a car. E.g., a test cycle that returns 40k cycles is NOT going to last 100 years. All we really know from the data is that the LEAF cells are no where near as robust as competitors.

A better way to look at this data is that a cell that lasts 500 cycles in a particular environment and use profile will last ~ half as long as a cell that lasts 1000 cycles in the same environment and use profile. And that evaluation is also suspect because these cells do not exist in isolation once they are packaged into modules and into a battery case.

For the LEAF we have a quadruple wammy: inferior cell, in inferior packaging, with higher max voltage, under higher thermal stresses.
 
SageBrush said:
A better way to look at this data is that a cell that lasts 500 cycles in a particular environment and use profile will last ~ half as long as a cell that lasts 1000 cycles in the same environment and use profile.

A cell with 500 cycles life and 10 year calendar life will outlast a cell with 1000 cycles life and a 2 year calendar life, at 100 cycles per year...
 
OrientExpress said:
https://pushevs.com/2017/09/08/lg-chem-will-introduce-ncm-811-battery-cells-evs-next-year/

Various articles and forums are 'trashing' the 22 kW DC 'fast charging' of the new LEAF. 2nd DCFC 27kW; 3rd+ 22kW

https://insideevs.com/watch-2018-nissan-leaf-40-kwh-fast-charging-issues/

https://speakev.com/threads/worried-about-leaf-2-rapid-charging-rate.101025/page-3
 
scottf200 said:
Various articles and forums are 'trashing' the 22 kW DC 'fast charging' of the new LEAF. 2nd DCFC 27kW; 3rd+ 22kW

As with most enthusiast sites, there is lots of speculation, combined a shortage of interpretive abilities that make for questionable claims that get echo-chambered in the blogosphere.

DCFC EVSEs do throttle the charge rate, I've seen rates as low as 8kW during a charge session, and it is not uncommon to see rates in the 20kW and lower during a session.

In 2 weeks I will have an '18 for a week or so to evaluate the "Drive the Arc" charging network in Northern California. We plan to drive the entire network from Monterey to Lake Tahoe and back to get some background on long-distance driving with multiple DCFC charge events in various driving situations, (urban, flat road freeway, hilly freeway, mountain driving, and long downhill freeway).
 
OrientExpress said:
scottf200 said:
Various articles and forums are 'trashing' the 22 kW DC 'fast charging' of the new LEAF. 2nd DCFC 27kW; 3rd+ 22kW
DCFC EVSEs do throttle the charge rate, I've seen rates as low as 8kW during a charge session, and it is not uncommon to see rates in the 20kW and lower during a session.
You are suggesting it is a coincidence that many qualified people have seen the 2nd and 3rd DCFC charging session drop to 22 kW and you believe those are by chance all the fault of the EVSE and NOT the LEAF forcing that lower kW rate? From my reading and a few videos recently, a lot of experienced EV owners are seeing this.

The InsideEVs article is getting national exposure for sure.

Obviously, if you are using the LEAF for daily driving this is not an issue. It seems as the battery is 40 kWh tho people believe that is over the hump of long distance traveling.
 
scottf200 said:
Obviously, if you are using the LEAF for daily driving this is not an issue. It seems as the battery is 40 kWh tho people believe that is over the hump of long distance traveling.
Or they are just playing, trying out the new car.

So I'm not convinced that the majority of people will find the QC throttling a practical problem but it says loads about the battery itself -- none of it good. The **** will hit the fan come summer time when people find that their battery simmers in 40 - 45 C temps for months on end , for hours and hours at 100% SoC in the unsuspecting who plug in daily. The pack will not cool down enough to allow decent longevity. So I surmise ..
 
As with most enthusiast sites, there is lots of speculation, combined a shortage of interpretive abilities that make for questionable claims that get echo-chambered in the blogosphere.

One also encounters the usual paid shills whose job it is to loudly claim that there is nothing wrong with the sponsored product, and that anyone who thinks there is must be stupid.

In 2 weeks I will have an '18 for a week or so to evaluate the "Drive the Arc" charging network in Northern California. We plan to drive the entire network from Monterey to Lake Tahoe and back to get some background on long-distance driving with multiple DCFC charge events in various driving situations, (urban, flat road freeway, hilly freeway, mountain driving, and long downhill freeway).

Most likely we will never see his review of this trip.
 
SageBrush said:
scottf200 said:
Obviously, if you are using the LEAF for daily driving this is not an issue. It seems as the battery is 40 kWh tho people believe that is over the hump of long distance traveling.
Or they are just playing, trying out the new car.

So I'm not convinced that the majority of people will find the QC throttling a practical problem but it says loads about the battery itself -- none of it good. The **** will hit the fan come summer time when people find that their battery simmers in 40 - 45 C temps for months on end , for hours and hours at 100% SoC in the unsuspecting who plug in daily. The pack will not cool down enough to allow decent longevity. So I surmise ..
I've read enough in forums and such that these 40 kWh LEAF owners want to use them to travel some modest distances. ie. not weekly but a several times per year. Some have anticipated the 40 kWh and expected to to be equal or better than the previous LEAF. I was equally surprised.
 
I for one am now looking for a loaded '15 Leaf to get me through the next year or two, until a better car comes along. I might be able to baby a 40kwh Leaf and have modest capacity loss, but I'm not going to pay $350 a month to do beta testing for Nissan. If they want to loan me a car for free I'll do it.
 
scottf200 said:
I've read enough in forums and such that these 40 kWh LEAF owners want to use them to travel some modest distances. ie. not weekly but a several times per year. Some have anticipated the 40 kWh and expected to to be equal or better than the previous LEAF. I was equally surprised.
There are always the buyers who try to push the EV envelope range as reported by EPA and then are disappointed when winter arrives or the battery degrades 5 - 10%.

They are just uninformed. I'm talking about the more reasonable group that buy a battery range a good 150% over their daily use and quite reasonably anticipate 10 years of use without drama for their $30k+ USD. Signs are all pointing towards disappointment by the 40 kWh LEAF for this group, and I find that sad. These are the second wave of EV buyers and I cannot shake the feeling that Nissan is setting them up for failure. They are not going to say "my bad. Next time Tesla." They are going to say "EV is a fail."
 
SageBrush said:
scottf200 said:
I've read enough in forums and such that these 40 kWh LEAF owners want to use them to travel some modest distances. ie. not weekly but a several times per year. Some have anticipated the 40 kWh and expected to to be equal or better than the previous LEAF. I was equally surprised.
<snip>
They are just uninformed. I'm talking about the more reasonable group that buy a battery range a good 150% over their daily use and quite reasonably anticipate 10 years of use without drama for their $30k+ USD.
<snip>
My feeling is that a *large* percentage of buyers of this '150' mile LEAF are driving < 100 miles each day and will be fine with the degradation. Plus what is the climate of where most of these LEAFs will be purchased. Japan, Europe, and more moderate USA? I think it will continue to have large sales and that the next generation in 1-2 years will have an active liquid TMS. I'm absolutely am not nor have ever been a fan of their current TMS method but I think the '150' miles may have gotten them over a it-wont-matter hump. Yes, I do think Nissan screwed the Gen 1 buyers and will have some fall out from the Gen 1.5 buyers.

Some explanations for the range and questionable SOC meters 'linear' accuracy -- watch at x1.5 speed via gear icon
Bjørn Nyland - Published on Mar 4, 2018
In earlier videos about the new Leaf, I assumed that the battery had massive heat loss due to high load. It turns out that the SoC displayed in the screen is lower than what LeafSpy shows. The Leaf would go farther than expected. But it should get a firmware fix for that "bug" I talk about in the video.
https://www.youtube.com/watch?v=bbGQkj7DnXc
 
My thoughts on the QC throttling issues are still in progress and with my "current" job, this could conceivably be an issue come July but the reality is

**Loved the full speed charging my S30 provided me but it still only covered 95% of my driving needs and covering that 5% was expensive.

** Not loving the slowdown that the 40 kwh LEAF has but the reality is, its still a MUCH MORE convenient car to drive and yeah E Pedal does a great job of allowing me to overlook things ;)

(yes, its pro LEAF!)

http://daveinolywa.blogspot.com/2018/03/2018-fast-charge-rates-regen-fast.html
 
Dave:

I just read your latest blog post, (spoiler the interesting stuff is not until the end! :D) but it looks like a typical 2018 QC session is doing the usual throttling at about 50% for temperature management.
 
OrientExpress said:
Dave:

I just read your latest blog post, (spoiler the interesting stuff is not until the end! :D) but it looks like a typical 2018 QC session is doing the usual throttling at about 50% for temperature management.

So, OrientExpress , you are confirming that 22 kW is expected on the 40 kWh LEAF when DCFC charging.

"Finally; I saw a Bolt charging at 130 amps at EVGO EV2 at Tacoma Mall and was impressed until it hit about 55% and the rate dropped to 60 amps or about 22 KW..."
 
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