Disappointment with battery capacity and "Nissan miles"

[LEAFfan]

I know this is an old post, but I am replying to it because it captures my disappointment as well, which I have had for nearly two years now. I'm sorry I don't read the forum all the time; I am very busy. Nevertheless, I searched and scanned the forum for a solution, but the search did not find one for me easily.

First of all: My driving habits: 35-38 mph, flat city streets, 12 miles/day, N California weather (generally mild), ECO mode always, charge to 80%, never turn on heat OR A/C, do not slam on accelerator at all, and the onboard indicator says 4.9 mi/kWhr. Car received ~Aug 2011.

I absolutely agree that there is a difference between "Nissan miles" and actual miles. In fact, I record before and after EVERY charge, both the change in "Nissan miles" from the "miles to go" indicator, and my actual odometer miles. The ratio between these two is about 60%, that is, the car actually goes about 60% the miles you would expect if you believed the "miles to go" indicator. So to be safe, I generally divide the "miles to go" by about a factor of two!!

I have had my Leaf serviced by Nissan, and they found nothing wrong, and they did one software update, too.

Thus, to me, it appears that the "miles to go" indicator grossly overestimates the distance available. Why is this? You might argue that, "You are heavy on the accelerator." Maybe so, but it would make the car really hard to enjoy if I CRAWLED out from every light. I accelerate just like the rest of the traffic, without over-accelerating. Anyway, no matter what one might say about my driving habits, my numbers are exact: the "miles to go" display change is far larger than the actual miles driven, even though my driving habits (see above) are near-optimal

Several thoughts:

(a) Given that there are several computers on board, I do not see why the car does not dynamically adjust the conversion factor, say, once a week or once a month. The car has the actual data on odometer miles driven for a certain degree of charge, and it also knows its own "miles to go" estimate. There is really no reason why the conversion factor would not be 1.0; this is just a little programming. This would compensate for many differences between drivers, and the display would be much more accurate.

(b) Could the overestimation be intentional? I know this has been implied before. I don't have an opinion and I don't really care, but it would seem to be in the best interests of Nissan for this display to be accurate.

I am a Nissan Leaf lover, and I tell people about all the nice and wonderful aspects of this car, EXCEPT I tell the truth about the difference between "miles to go" and actual distance one can expect.

regards to all, and I hope I have missing something simple I can do to improve this,
wescom

Only 4.9 at 35-38mph? I would get at least 6.0 at those speeds. Just last week, I drove 53mph (55 on speedo) for about 18 miles (slightly downhill), then at 58 (60 on speedo) for 5 more and ended at the station with 5.8m/kW h. Something doesn't seem right about yours. However, capacity has no effect on m/kW h.

 

[wescom]

Thanks for your comment! Makes me wonder even more if there is some unsolved problem with my Leaf.

Maybe it is the mass I am carrying? The trunk is full of emergency gear; thought this would be irrelevant since the Leaf itself is already heavy with the battery.

Is there any other way to find out if the overall efficiency is bad? Note that I do not show any battery degradation judged from the bars available just after charge.

 

[RegGuheert]

Note that I do not show any battery degradation judged from the bars available just after charge.

You will always get 12 charge bars after a full charge. You want to look at the thin bars to the right of the charge bars, anytime. If there are 12 bars shown there, this does NOT mean that you have no degradation, but rather that you should have at least 85% of your original battery capacity (and possibly as low as 81% capacity by some estimations).

 

[planet4ever]

Only 4.9 at 35-38mph? I would get at least 6.0 at those speeds. Just last week, I drove 53mph (55 on speedo) for about 18 miles (slightly downhill), then at 58 (60 on speedo) for 5 more and ended at the station with 5.8m/kW h. Something doesn't seem right about yours. However, capacity has no effect on m/kW h.

Thanks for your comment! Makes me wonder even more if there is some unsolved problem with my Leaf.

Don't be too worried. LEAFfan is somewhat famous here for being the most ardent hypermiler we have. Like many other LEAF drivers, I have never gotten more than 5 m/kWh, and my lifetime average is about 4 m/kWh.

As for the "Distance to Empty" number, that we usually call the GuessOMeter, or GOM, we all agree that it is very unreliable. There are some reports, including from LEAFfan, that they have improved it quite a bit for 2013. But the fact remains that it has a nearly impossible task. It is trying to predict the future based on the past. Yes, the algorithm they used in your car and mine was abysmal. We don't know exactly what it was, but it clearly was heavily weighted by the last few miles you drove. If the last two miles to your home are through a residential area with few if any traffic signals, the computer is going to decide (if I can be a bit anthropomorphic) that you have suddenly become a much better driver than you used to be. When you get home it is going to have a very optimistic opinion as to how far you can go the next day. Sadly, unlike a human being or a well-written program, it learns nothing from its past mistakes.

Ray

 

[DaveinOlyWA]

I know this is an old post, but I am replying to it because it captures my disappointment as well, which I have had for nearly two years now. I'm sorry I don't read the forum all the time; I am very busy. Nevertheless, I searched and scanned the forum for a solution, but the search did not find one for me easily.

First of all: My driving habits: 35-38 mph, flat city streets, 12 miles/day, N California weather (generally mild), ECO mode always, charge to 80%, never turn on heat OR A/C, do not slam on accelerator at all, and the onboard indicator says 4.9 mi/kWhr. Car received ~Aug 2011.

how often do you reset that? daily? because if you are not and its long term average then i say its about right and you are "better" than average.

unless you reset it daily, it will NOT give u an indication of your performance because your performance will vary by season, temperature, precipitation and even the direction of the wind. terrain is a given and therefore static unless you make a habit of "going where you have not gone before"


i say reset it daily along with one of your odometers and record both for a month and report back. betting you will see anything from the high 3's to the low 6's

 

[Reddy]

Only 4.9 at 35-38mph? I would get at least 6.0 at those speeds. Just last week, I drove 53mph (55 on speedo) for about 18 miles (slightly downhill), then at 58 (60 on speedo) for 5 more and ended at the station with 5.8m/kW h. Something doesn't seem right about yours. However, capacity has no effect on m/kW h.

Thanks for your comment! Makes me wonder even more if there is some unsolved problem with my Leaf.

Don't be too worried. LEAFfan is somewhat famous here for being the most ardent hypermiler we have. Like many other LEAF drivers, I have never gotten more than 5 m/kWh, and my lifetime average is about 4 m/kWh.

1+ on LEAFfan. Sounds like you're doing pretty good. I also get about 4-5mi/kWh in city 35-38mph up here in the "cold". Only at very warm temps like Phoenix will you get those super high numbers. Yes, you can do better, maybe even up to 6, but that will require a constant speed with no traffic lights. You get "some" energy back with regen, but not all of it. My best was 6.2 mi/kWh in August, no A/C, 11.9 mi, 0.5hr, so a bit less than 25 mph average, including the stop lights. For the month of August, my average was 4.6 mi/kWh at an average speed of 27 mph. Let's not talk about my winter 2.3 mi/kWh numbers.

I'm a decent hypermiler, but not excessive. I coast in N up to the lights, shift to D to slow, or ECO to slow more. Slow steady acceleration, no jackrabbit off the line, but otherwise, I pretty much drive normally. My average speed is low because almost all of my driving is in a small town (35 mph limit) with short 1-2 mi trips (e.g., the least efficient driving for an ICE).

Reddy

 

[EvansvilleLeaf]

Your driving and miles/KWh are just peachy - better than mine for sure (4.2 ish average). Your expectations however were unrealistic, although you are indeed correct that the GOM is worse than useless and, itself separate from the actual range, a major reason for disappointment. We all signed papers that listed varying ranges on 100% charge that ranged from 42 and up. If you didn't, then the dealer may be to blame for that, but still some expectations should just be normal. I'm about as far from a battery expert or EE as it's possible to get and it was pretty obvious even to me that variation would be substantial. Your Leaf is doing fine, and so are you - just not what you hoped is all.

I've never broken 100 by the way, but average a bit over 60 on 80% even in 30s F. I wouldn't have got one if that was a problem.

 

[themotorman]

My June 2011 leaf is either having serious battery problems or the gages are screwed up. ( FYI: So you know I am a techy, I am an EE design electric motors , control systems , and have built an electric car from scratch. )
I charge it overnight and it says it's full, charger shuts off, in the AM. It then reads about 70-80 "miles". If I do a check with my LEAF app on my phone it says it is fully charged BUT I have 44 miles range...mm strange !! Now I set the trip to zero and drive for about 32 real miles as showing on trip and the "miles" shows I have about 14 left.. SO my real total is only 44 miles... I do not know what this means as I don't have real data other than the above. When fully charged it does show all bars full. The bar scale is useless as it really doesn't give me any data. What is the scale , what units, Ah-hrs would have been nice!
My guess is that some cells have failed or are failing so I am going to the dealer next week and will post the result. Just curious to see if anyone else is having a similar experience.
FYI I have had about 3.6 miles/kw-hr, energy usage since new . I drive the car about the same as a gascar around town and keep under 65 on the freeway. Most driving is about 60% street and 40% freeway. Not much air conditioning or heater.
PS I do love the car and think that Nissan did a great job but the battery is a problem...

 

[planet4ever]

My June 2011 leaf is either having serious battery problems or the gages [sic] are screwed up.

It is probably a combination of three things:

• Your 2½ year old battery definitely has lost some capacity. How much depends on your climate (please give us an indication in your profile of where you live) and how you have treated it. Do you still have 12 capacity bars? Those are the skinny white ones, bottom two red, to the right of the charge bars.
• The gauges are indeed screwed up, in particular the one you are focusing on. It isn't really a gauge at all, since it is not a display of any measurement. It is a computer guess as to how far you can go, so we call it the GuessOMeter or GOM. The algorithm it uses is lousy, the input measurements it uses are suspect, and it is heavily weighted by how you were driving yesterday. It's best to just ignore it.
• The battery can't hold as much electricity when it is cold. Again, we don't know where you live, but it's been cold recently in most of the US, so there is a good chance that is also a factor for you.

I do not know what this means as I don't have real data other than the above. When fully charged it does show all bars full. The bar scale is useless as it really doesn't give me any data. What is the scale , what units, Ah-hrs would have been nice!

Try volts, though the scale is not linear by voltage. Lithium cells are fully charged (at least as fully as feasible for long life) at about 4.1v. The scale is not trying to tell you how much electricity you have in the battery, but how much you have as a fraction of what it can hold. The bars are far from useless. See these charts that Tony Williams created. Be sure you use the one for the age and current capacity of your battery.

My guess is that some cells have failed or are failing

Probably not. In most cases it seems that all of the cells degrade at pretty much the same rate. Besides, it won't be covered under warranty unless a) it is a sudden loss, or b) you are down to 8 capacity bars. As for determining sudden loss, the battery monitor maintains statistics that Nissan can pull, and did pull last summer and the summer before when you had your battery check. You did get those checks, didn't you? If you didn't, you have no battery warranty.

Ray

 

[Stoaty]

My June 2011 leaf is either having serious battery problems or the gages are screwed up. ( FYI: So you know I am a techy, I am an EE design electric motors , control systems , and have built an electric car from scratch. )

The only way to know your current battery capacity is with the Leaf Spy (link in my signature), LeafDD (my favorite, search the forum) or equivalent. I highly recommend this if you are concerned about your capacity.

 

[Pipcecil]

Also to note, the range meter in the car is an algorithum based on the recent driving. So, if you went down neighborhood streets for a few miles at low speeds, it artifically inflats that number when you get back in your car after it charged.

Carwings app data takes an average of the your entire last trip to calculate the range. So that is why its a bit more accurate, especially if you are repeating the same trip.

 

[themotorman]

My June 2011 leaf is either having serious battery problems or the gages are screwed up. ( FYI: So you know I am a techy, I am an EE design electric motors , control systems , and have built an electric car from scratch. )

The only way to know your current battery capacity is with the Leaf Spy (link in my signature), LeafDD (my favorite, search the forum) or equivalent. I highly recommend this if you are concerned about your capacity.

THanks, I am impressed. The app looks very useful. I will get this and then be informed. It might not change the outcome but knowledge is very valuable.
I have had all the recommended service checks and each time the battery looks great.
BTW the cell voltage doesn't not tell how much Ahr is stored. It is really only useful to stop charging and shutdown disacharge. The Li cell has a very flat voltage vs. discharge curve over most of it's useful range unlike other chemistries.
I like 2.5 for the low limnit and 3.65 for the upper. These limits are those provided by most of the LiFePO4 battery manufacturers. Other chemistries have different limits.

 

[JRP3]

In fact other chemistries do have a voltage slope that does equate to SOC, and since the LEAF does not use LiFePO4 I'm not sure why you would use it for a comparison.

 

[themotorman]

In fact other chemistries do have a voltage slope that does equate to SOC, and since the LEAF does not use LiFePO4 I'm not sure why you would use it for a comparison.

My mistake... When I bought the LEAF I did not know as much as ( or as little ) as I do now about the chemistries using Li .
The LIFePO4 chemistry is one that I used for the ecar that I built and so I am familiar with it. I decided when designing my "fuel gage" to just use kWhrs remaining as I can mentally calculate from it if I can make it home. This is really similar to how most of us use the fuel gage in a gas car.
Nissan could have put "kWhrs remaining" where the silly tree is displayed and made me, and may be a few others, happier.

 

[sgoyal]

Hi All,

My car is 2012 and has about 12K miles. All software updates have been done by the dealer, and tires are at 40 psi. In the recent cold weather (mornings have been 25-30 F), the range on my Nissan Leaf has dropped from 70 to about 45 miles. This is all non-freeway stop and go driving under 50 mph. I am barely getting 45 miles without using heat or the front defroster. When I use those features, the range drops to around 35-40. This makes the car practically unusable as I can't drop the kids to school, commute to work and back (47 mile RT) . Nissan claims this is 'normal' for Lithium-Ion batteries, and is refusing to take any action. Luckily I'm dealing with an understanding dealer and they're going to bat for me. Fleetcarma compiled range data from 5400 Leaf trips taken at various temperatures, and came up with the below data. Again, very interesting, and I'm surprised this is not main stream news already.

http://www.greencarreports.com/image/100417498_fleetcarmas-analysis-of-nissan-leaf-driving-range-at-different-temperatures" onclick="window.open(this.href);return false;

Simply put, my gripe is that Nissan was not upfront and transparent about this cold weather factor. I understand there are some general disclaimers in the owners manual about effects of driver behavior, temperature on the battery range, but no one reads the owner's manual before buying a car. My dealer didn't mention a single word about this potential issue. Had I known this upfront, I never would've bought. Now I feel I'm stuck with this car for another 2 yr. till lease end. BTW, I like most other aspects of this car, and have even recommended it to several co-workers. This drop in range did not happen last year, when the car was only 2 months old.

Any recommendations? Sorry for a negative post.

 

[JRP3]

Nissan could have put "kWhrs remaining" where the silly tree is displayed and made me, and may be a few others, happier.

Certainly agree with that. Most of us who have done conversions use kWh or Amp hours to show actual energy in the pack.

 

[themotorman]

Hi All,

My car is 2012 and has about 12K miles. All software updates have been done by the dealer, and tires are at 40 psi. In the recent cold weather (mornings have been 25-30 F), the range on my Nissan Leaf has dropped from 70 to about 45 miles. This is all non-freeway stop and go driving under 50 mph. I am barely getting 45 miles without using heat or the front defroster. When I use those features, the range drops to around 35-40. This makes the car practically unusable as I can't drop the kids to school, commute to work and back (47 mile RT) . Nissan claims this is 'normal' for Lithium-Ion batteries, and is refusing to take any action. Luckily I'm dealing with an understanding dealer and they're going to bat for me. Fleetcarma compiled range data from 5400 Leaf trips taken at various temperatures, and came up with the below data. Again, very interesting, and I'm surprised this is not main stream news already.

http://www.greencarreports.com/image/100417498_fleetcarmas-analysis-of-nissan-leaf-driving-range-at-different-temperatures" onclick="window.open(this.href);return false;

Simply put, my gripe is that Nissan was not upfront and transparent about this cold weather factor. I understand there are some general disclaimers in the owners manual about effects of driver behavior, temperature on the battery range, but no one reads the owner's manual before buying a car. My dealer didn't mention a single word about this potential issue. Had I known this upfront, I never would've bought. Now I feel I'm stuck with this car for another 2 yr. till lease end. BTW, I like most other aspects of this car, and have even recommended it to several co-workers. This drop in range did not happen last year, when the car was only 2 months old.

Any recommendations? Sorry for a negative post.

I have 12 bars showing and still am getting only 45-48 miles... Next time I do a charge I will monitor the kW going in and see if it makes sense. It seems to take the 3.3 kW ( level 2 ) for at least 8 hours for an almost dead battery so that looks like the battery can take a full charge of around 28 kW-hrs...Since I get about 3.6 miles/kwhrs that should give me around 100 miles.. as it did when new. Based on the real miles of about 45 I must assume that I am only storing about 13 kwhrs...
I thought this would be reflected in the number of bars showing...cannot explain this...mmmmm.
I have not yet monitored the charge current as I usually charge at night but next time I will do it in the daytime and monitor current. Will post when I have done the charge test.

 

[planet4ever]

It seems to take the 3.3 kW ( level 2 ) for at least 8 hours for an almost dead battery so that looks like the battery can take a full charge of around 28 kW-hrs.

Sorry, nowhere close to that. The total battery capacity is 24 kWh, and Nissan has programmed the Lithium Battery Controller to lock out close to 10% of that, because lithium battery life suffers greatly if it is either charged or discharged completely. The most you can put into a new LEAF battery is 21-22 kWh.

Based on the real miles of about 45 I must assume that I am only storing about 13 kwhrs...
I thought this would be reflected in the number of bars showing...cannot explain this...mmmmm.

As I tried to say before, that is not the way the available charge bars work. They are a computed result from the dash computer which is telling you how full the battery is, not how much energy it is currently holding. To put it in the simplest terms, you will always see 12 bars if the battery is as full as it can practicably be. As the battery gets old, or the battery gets cold, each bar "holds" less energy.

Sure, most of us wish the LEAF had a display that told us how much energy the battery is holding, but it doesn't. Apparently the LEAF's computers themselves don't have access to a really good value for that, though there is a number available through the OBD-II interface that comes closer. We call it a "GID" on this board, in honor of member Gary Giddings who discovered it. The guys who know a lot more about batteries and electronics than I do talk about not being able to get good measurements except when the battery is at rest, and about very imprecise results from the monitor that is trying to measure current flow out of the battery.

Ray

 

[themotorman]

It seems to take the 3.3 kW ( level 2 ) for at least 8 hours for an almost dead battery so that looks like the battery can take a full charge of around 28 kW-hrs.

Sorry, nowhere close to that. The total battery capacity is 24 kWh, and Nissan has programmed the Lithium Battery Controller to lock out close to 10% of that, because lithium battery life suffers greatly if it is either charged or discharged completely. The most you can put into a new LEAF battery is 21-22 kWh.

Based on the real miles of about 45 I must assume that I am only storing about 13 kwhrs...
I thought this would be reflected in the number of bars showing...cannot explain this...mmmmm.

As I tried to say before, that is not the way the available charge bars work. They are a computed result from the dash computer which is telling you how full the battery is, not how much energy it is currently holding. To put it in the simplest terms, you will always see 12 bars if the battery is as full as it can practicably be. As the battery gets old, or the battery gets cold, each bar "holds" less energy.

Sure, most of us wish the LEAF had a display that told us how much energy the battery is holding, but it doesn't. Apparently the LEAF's computers themselves don't have access to a really good value for that, though there is a number available through the OBD-II interface that comes closer. We call it a "GID" on this board, in honor of member Gary Giddings who discovered it. The guys who know a lot more about batteries and electronics than I do talk about not being able to get good measurements except when the battery is at rest, and about very imprecise results from the monitor that is trying to measure current flow out of the battery.

Ray

The class action suite that I heard abount only talked about the number of narrow bars showing .. Nothing in it mentions kWhrs stored.. If what you say is correct then the number will always be 12...however i think we are not being careful about which of the two bar graphs we are referencing. Can you please check on this or give us a reference to the narrow bars and what they show, and let us know. Thank you.

 

[dgpcolorado]

The class action suite that I heard abount only talked about the number of narrow bars showing .. Nothing in it mentions kWhrs stored.. If what you say is correct then the number will always be 12...however i think we are not being careful about which of the two bar graphs we are referencing. Can you please check on this or give us a reference to the narrow bars and what they show, and let us know. Thank you.

The fuel bars are completely different from the capacity bars. The narrow "capacity bars" (CB) are not a linear scale. The top one represents 15% of the original battery capacity and the rest 6.25% each. This information came from a 2011 service manual and has since been corroborated by Nissan representatives. However, in measuring Amp•hours with our meters we have noticed that the first CB is lost at a bit more than 15%. The Amp•hours of a new battery pack for a 2011/2012 LEAF was about 66.25. (The numbers are unclear for the 2013 LEAFs since the chemistry and measurement algorithms changed in mid model year.) The EEs here can correct me, but as I understand it Amp•hours make a better capacity measurement than kWh because the latter is so sensitive to small changes in voltage.

For actual driving use, Gids are the most useful measurement. Each Gid is approximately 80 Watt•hours. The 2013 models have a %SOC gauge, although it is based on relative, not absolute, capacity, so each percent will decline in energy as the battery degrades.

The new Nissan 60 month/60,000 mile battery capacity warranty will replace the battery if it gets down to eight bars, about 66.25% of original capacity. But the warranty says that it will be brought back up to at least nine bars, not that it will necessarily be replaced with a new battery pack. The first replacements under warranty in hot states have been new packs thus far. YMMV.