Dumb**s alert: am I the first to drain it??

[SanDust]

Their feedback was that Nissan knows they have an issue with calculations of available distance and Human Interface issues under 2 bars of charge. So my problem was that I first charged the car to only 80%, then without driving it I thought I might need more so I charged for another 45 minutes, then I drove it, then I charged for 70 minutes, then I drove it.... bottom line is that it had trouble given all of that and the mixed driving of both highway and city street. It just wasn't able to provide me the feedback that I needed. They have a software update that has been tested and partially deployed in Japan that they believe will assist with this problem, and which should be pushed to the cars in the US soon.

This is heartening. Yes Nissan has a problem with the software. While some posters here have wanted to blame everyone and everything BUT the car, it became painfully clear after the Barron's reporter ran out of juice that the software was failing to accurately account for the energy used. The good thing is that software can always be fixed, but if you resist admitting there is a problem then it will never get fixed. FYI some people figured out the likely source of the problem pretty quickly. (So far Nissan engineering has been straight shooters. Nissan marketing not so much).

Sorry that you had the misfortune to experience the downside of being a early adopter, but at least your car is fine and you have a good story to tell!

 

[JRP3]

Their feedback was that Nissan knows they have an issue with calculations of available distance and Human Interface issues under 2 bars of charge. So my problem was that I first charged the car to only 80%, then without driving it I thought I might need more so I charged for another 45 minutes, then I drove it, then I charged for 70 minutes, then I drove it.... bottom line is that it had trouble given all of that and the mixed driving of both highway and city street. It just wasn't able to provide me the feedback that I needed. They have a software update that has been tested and partially deployed in Japan that they believe will assist with this problem, and which should be pushed to the cars in the US soon.

So this is a root cause of human error, with the contributing factor that one needs to be aware that when you hit the last 2 bars, the calculation gets a little dicier.

This is where a state of charge meter, in amp hours or KWH's, would be so useful. Yes they need to improve the software, but if there was a simple numerical gauge that showed you exactly how much charge was left you would have had a more precise readout of where the battery was at, and when it showed "0" and the car stopped you'd know that there was no problem and you just ran out of juice. It baffles me why they don't include such a simple device that almost all home conversions have and I'm sure could be implemented in their software.

 

[charlie1300]

Their feedback was that Nissan knows they have an issue with calculations of available distance and Human Interface issues under 2 bars of charge.

Assuming best case (100 miles on 100% charge) when you have less that two bars you have less than 16.6 miles left. But the bars only tell you if you have less than 16 or less than 8 miles left. So how was it hard for Nissan to foresee that there would be "Human Interface issues under 2 bars of charge"? There isn't enough info for the human to make a good decision.
A software update won't fix the problem. Only an accurate SOC gauge will.

 

[garygid]

Changing the SOC-Estimation software to use the correct data can make a HUGE difference.

To have the LEAF's software estimate 16% usable energy remaining when it is actually only 3% cannot be corrected with just a higher-precision display.

 

[SanDust]

We no longer have to guess, fumble, or compare with other cars as we have all the proof we need that the capacity available to Leaf drivers is 24kWh.

We haven't had to guess for a while. If you look at the facts it's obvious that you don't have 24 kWh avaiable.

Far and away the best numbers are those we can get from the EPA. The EPA found that, starting with a fully charged battery pack. the Leaf can go 73 miles until it's no longer able to continue running on the test cycle. The EPA also measured the number of kWh, from the wall, needed to fully recharge the battery pack after it hit this depletion point. Using this measurement it calculated that the Leaf needs 34 kWh from the wall to go 100 miles. This means that, from empty to full, the Leaf uses 24.82 kWh from the wall. Unless you're suggesting that the charging efficiency is 97% there is no possible way that you're putting 24 kWh back into the battery. If the charging efficiency is 80% then you're looking at 19.85 kWh. If it's 85% then it's 21 kWh. Even if you use a fantastic number like 90% it's only 22.3 kWh. 24 kWh is just not happening.

As far as the Volt is concerned, if you have a known number it's folly to ignore it. The reason the Volt is so useful is that we KNOW for a fact that the Volt uses 10.2 kWh to go 35 miles on the EPA adjusted test cycle. That's an efficiency of 291.4 wh/mile. The Leaf goes 73 miles ON THE SAME DRIVE CYCLE. If we accept your claim that he Leaf uses 24 kWh to go these 73 miles, it's efficiency would be 328.77 wh/mile. That's a whole lot worse than the Volt. In fact it's 13% worse, which would be most disappointing given that the Leaf weighs 400 pounds less - a 25% efficiency difference. If you believe this then: (1) you'd have to conclude that the Leaf is not ready for prime time; (2) you'd have to conclude that Nissan should fire all their engineers and start over because their engineers obviously don't know what they're doing; and (3) you'd have to conclude the EPA is delusional when they conclude that the Leaf gets 99 MPGe and is 6% more efficient than the Volt. Not realistic to accept any of these conclusions much less all of them.

The justifications for your 24 kWh claims are more noise than signal -- some random guy thinks they heard some other random guy say something. No real data. The only fact is that the measured capacity of the battery is 27 kWh. Assuming that this is accurate, and it's not exactly a reliable number, this hardly means that you have 24 kWh available. In fact it suggest the opposite. For if the capacity is 27 kWh, then using 80% of the capacity would mean that you had 21.6 kWh available. AFAIK Mark Perry has only said that the Leaf uses "at least 75%" of the battery pack. 75% of 27 kWh is 20.25 kWh.

 

[ericsf]

What I find sad is that this thread was turned into a sensational (in a bad way) article about the LEAF : http://jalopnik.com/#!5780215/nissan-electric-car-stranding-owners

It doesn't make the news when some idot runs out of gas on the road but when an electric car runs out of juice it does. There is a mob (Chevron, Exxon, BP, etc...) out there that's waiting for any occasion to shoot down EVs. If you really like your LEAF and want a version 2.0 to ever see the light of day, don't feed those people with material they can take out of context and misuse to scare the mass market.

Maybe Kelangst was trying to test the limits of the LEAF, which don't get me wrong is great information for the rest of us, but look at what this was turned into by some jackass wanabe journalist.

Otherwise, car's mileage estimate go up and down as the driving conditions change and shouldn't be used as the only indicator of how far you can go. If your ICE "low gas" was ON but the car would tell you you can still drive 17 miles, what would you do? Those miles are estimates and are not meant to replace the battery / fuel jauge and some common sense in the driver seat. When you get below 2 bars it means you're on the reserve. Those are marked in RED. Turle mode is only to get out of harm's way if you happen to ignore the warnings and continue to drive.

 

[JRP3]

Our conversions using LiFePO4 charge at around 92-93%, I don't know if LiMn has different charge efficiencies but 95% may not be impossible.

As for the negative article, that's going to happen. Nissan has a problem with their estimation software, and I think their turtle mode should engage sooner and give more low speed range. My conversion does, I once went about 2 miles at reduced speed at about 20 mph and got home. It actually started slowly reducing power about 4 miles out and gradually ramped it down as I went. Gave me plenty of notice that I was getting low, and by reducing power it increased my range. Nissan should have consulted me :mrgreen:

 

[klapauzius]

Maybe Kelangst was trying to test the limits of the LEAF, which don't get me wrong is great information for the rest of us, but look at what this was turned into by some jackass wanabe journalist.

I did not (and I think Kelangst too) try to test the limits of the car. Going on a 40 mile roundtrip with 60 miles on the range estimate does certainly not sound like testing the limit.

A big difference between "an idiot running out of gas" and us would also be that there are plenty of gas stations around, but no charging stations (so far). So having a correct range estimate is very (!!!!) important.

I think it also wouldnt help "the cause", if all the bad news are censored (it certainly did not do the Soviets any good back in the days), as Nissan seriously needs to change the way the range is estimated. Putting the car out as it is right now, without fixing this problem of the range estimation, would probably do more harm in the long run.

 

[garygid]

It was reported that the Nissan engineers have a software "upgrade".

What does it do differently?

 

[AndyH]

We no longer have to guess, fumble, or compare with other cars as we have all the proof we need that the capacity available to Leaf drivers is 24kWh.

We haven't had to guess for a while. If you look at the facts it's obvious that you don't have 24 kWh avaiable.<snip>

Far and away the best numbers are those we can get from the EPA. The EPA found that, starting with a fully charged battery pack. the Leaf can go 73 miles until it's no longer able to continue running on the test cycle.

Negative, Ghostrider - that's not the meaning of the EPA's 73 mile number.

EV range tests are run until the pack's empty, or the car can no longer maintain speed, or with some shortened test designed to model a run to empty. The EPA then deducts 30% from the 'as tested' range to arrive at their 73 mile range number.

In their application for EPA testing, Nissan NA reported that their battery is 24kWh, and that they can run 111.7 and 113.7 LA4/UDDS miles per charge and 94.9 and 97.1 highway miles.

http://www.mynissanleaf.com/viewtopic.php?f=4&t=2433

The facts are here on the forum, can be found in black and white with Nissan letterhead, and are on video spoken by employees of Nissan NA. If that doesn't work for you then there's no way I can help you.

 

[Kelangst]

Well I have to say that I Am a little frustrated by the article. I was sent a PM asking to comment. My comment was:

I am going to post on this in a few, but the bottom line is I simply drove it out of power. They had engineers look at the car extensively and test everything, and the end result is that I drove too far for the charge I had. Simple answer.
  Sent: Wed Mar 09, 2011 5:01 pm

I took ownership of my driving mistake, with a slight complaint that the remaining miles was a little deceptive and the behavior unexpected. I didn't intend for my post to be taken as a complaint about the car, and in fact I think I clearly said I felt it was my fault, that Nissan responded well, and that there is a fix in the works for the display.

This started as a self-deprecating statement that I thought would be worth conversation on the board. Forgot the simple rule that once it is on Internet, it is out of my control how it is used. Guess I might not be posting my experiences again. :-(

 

[Coffee_Slurry]

Range limitations aside, I'm curious to know more about the "It wouldn't Turn Off" problem.

That can't be explained away as human range approximation error.

Was the root cause of that learned?

 

[abasile]

Guess I might not be posting my experiences again. :-(

Please do continue posting your experiences. I, for one, have certainly appreciated the opportunity to read this thread! Let's face it, EVs are revolutionary. Anytime you have something revolutionary, there is going to be hostility from somewhere. The personal testimonies of happy LEAF owners will speak much louder than wannabe journalists who cherry pick quotes off of Internet message boards. There has to be something negative to share; otherwise, folks will wonder if all of the positive testimonials are legitimate!

 

[SanDust]

Negative, Ghostrider - that's not the meaning of the EPA's 73 mile number.

After the EPA numbers were released, I pointed out that they precluded the Leaf from using 24 kWh during a drive cycle. In response to objections that the EPA's calculations were suspect, I further pointed out that the EPA came up with the number of kWh needed to fully charge a completely discharged battery per J1634 by measuring not calculating. What I got then was the assertion that the EPA did not use J1634. We've moved past that mistake but somehow we can't reach the rather obvious conclusion that flows from understanding how J1634 works.

You apparently think it matters that the EPA concluded that the Leaf has a range of 73 miles. It doesn't. What matters for present purposes is that when the EPA measured the energy needed to fully replenish the Leaf pack it found that it took 24.82 kWh. That's a measurement. It could have been made after 83 miles or 93 miles or 103 miles or 153 miles (it was made after 104 miles if that matters). What earthly difference does it make? The battery is dead. You plug it in. You measure how much juice goes into the battery. You find the battery is fully charged after 24.82 kWh. End of story.

You need to explain how you manage to get 24 kWh in the battery from 24.82 kWh at the wall. Not happening with any current technology I'm aware of.

 

[SanDust]

Range limitations aside, I'm curious to know more about the "It wouldn't Turn Off" problem.

That can't be explained away as human range approximation error.

Was the root cause of that learned?

This is a great point. Yes there is a lingering question. While the sudden drop in range suggested a software problem, the inability to turn the car off suggested a hardware issue.

 

[DaveEV]

You need to explain how you manage to get 24 kWh in the battery from 24.82 kWh at the wall. Not happening with any current technology I'm aware of.

That would reflect a charge efficiency of 96.7%. Charging losses when done at a moderate rate with LiIon batteries are typically in the high 90% range. A well designed charger should also be in the high 90% range. I don't see it as being implausible...

 

[mxp]

< cut >
This started as a self-deprecating statement that I thought would be worth conversation on the board. Forgot the simple rule that once it is on Internet, it is out of my control how it is used. Guess I might not be posting my experiences again. :-(

Hey Kelangst, Pls do continue to share your usage experiences. Yes, it's the internet and you can't stop it for what it is. But, your insights were extremely valuable. So thank you for sharing and do continue to do so!

WHat would be more interesting (or frightening) is if you would ever experience that situation once again; assuming your battery was conditioned over time of a course of 2-3 months or so. Only then you would have the confidence, for sure, that there is something or nothing "faulty" with the battery or anything else in the car's systems.

I am not sure if I had ever seen a "best practices" written by Leaf owners for initial charging/discharging guidance as new Leaf owners once they receive delivery of their new vehicles. A "best practices" guide could cover topics like what you previously did with topping off a previous charge and the "potential risks". This type of information will help new Leaf owners understand different use case scenarios and educate those of us about non-linear battery depletion effects. (And not just to heed the 80% charge advice)


edit: Ok, I saw something similar here: http://www.mynissanleaf.com/viewtopic.php?f=27&t=2957
but it does not fully cover use case scenarios all in one thread.

 

[ericsf]

Hi Kelangst,
Sorry for the "anger" but that was totally directed to the people who turned your valuable experience in a LEAF disaster story. I guess other posters are right: that's the nature of the internet and transparency is always better. I am glad to know there are potential range estimation issues when the charge goes in the last 2 segments and the very short distance you can drive in "turtle mode".

Personaly I was not bothered by the range fluctuations on my LEAF. A couple of times now I drove out of my garage with 85 "Nissan miles" on the dashboard which droped below 50 after driving on the freeway for a few minutes. I knew I was mostly doing city driving the previous day and the estimate drop made sense to me. Except for the bug than may have happened in your case, I don't think Nissan can do much about the estimate "errors" unless the drivers would tell the car where then plan to go and how fast they'll be driving.

"Where are you going, Dave ?"... not sure I want that.

 

[palmermd]

"Where are you going, Dave ?"

Dave's not here, man.

Sorry if you felt your post did not go down the path you intended. I hope it does not discourage you or others to post issues with your car. I'm glad to hear you got a good response from Nissan, and I hope they continue to provide great customer support for issues.

 

[EdmondLeaf]

Why we do not treat this forum for what I believe was created - to share our experiences and try to learn as much as possible because there is a lot to learn. For me still a long way to get my Leaf (Oklahoma) and I plan to use 70 miles round trip to work, but I will charge at home and work so I can't envision how range, running of charge, can be a problem for me. I do not count on charging infrastructure in near future, but strongly believe this car will be great for me. Electric company won’t give me special rate to charge Leaf, also not interested to buy back solar power. So I know I am on my own, for now, but convinced that will change sooner or latter. People laughed when 15 or so years I was buying very expensive CF bulbs. They are not laughing now; they are buying LED bulbs together with me.

How many drivers run out of gas today - I wonder who cares?