Range/Capacity loss determination debate (and more)

[nosuchthing]

Two cases = statistically insignificant. Get me 10,000 cases. Then we have something to latch onto. I don't smoke pot, and of course smoking anything isn't good for the lungs. Obviously.

I mentioned pot only to illustrate the connection between smoking cigarettes and lung cancer not being caused by carcinogens, necessarily, but by radioactivity. And it could be easily eliminated if someone had the chutzpah to step on RJ's toes and tell them to stop fertilize tobacco plant with Apatite.

Lung cancer rates increased significantly during most of the 1900's(6). It's no coincidence that between 1938 and 1960, the level of polonium 210 in American tobacco tripled commensurate with the increased use of chemical fertilizers...

Read all about it here...

http://www.webspawner.com/users/radioactivethreat/" onclick="window.open(this.href);return false;

Surfing Slovak. Thanks for the correction, I majored in English in HS. Anyway, my take on this whole battery thing is that no one really knows, including Nissan, what the long term prognosis is, and what will come out of this experiment, really, 5 years down the pike, pun intended. We are the guinea pigs here, got a nice cashback on the deal, and loving the care-free, non-polluting car. Full charge is a necessity for us so whether my bet will pay off is secondary to our need to have the range. My philosophy is that I will be swapping those cells one way or another in 5 years for a much denser pack, with twice the range so it matters not what happens to the pack as long as it performs near its max capacity until that time. And since we're at 30,000 miles already and have nothing to report in terms of range loss, I think I earned my right to share my not-so-humble opinions with the world out there.

I'll be the first to admit if the pack shows range loss. And...it would be nice to hear from everyone participating what their situation is in terms of charging vs. range so we can get some hard data on this.

 

[LEAFfan]

ILECTRIC, look on your LEAF's door frame. It says 36 PSI, not 32. And 41 makes them wear much better. I have almost 14K miles, and they still look almost new.

 

[KJD]

I'll be the first to admit if the pack shows range loss. And...it would be nice to hear from everyone participating what their situation is in terms of charging vs. range so we can get some hard data on this.

Did you fill out the plug in america survey on this subject ?
http://www.mynissanleaf.com/viewtopic.php?f=27&t=10494" onclick="window.open(this.href);return false;

 

[ENIAC]

So you may ask, how in the world does radioactive Polonium get into a cigarette, right? It's because tobacco companies require growers to fertilize tobacco fields with a mineral Apatite, which natually contains radioactive Polinium. Apatite robs the plant of nitrogen and gives the tobacco leaf a desirable taste, which then makes you keep buying the product/brand, save for the nicotine addiction, of course.

Well, according to the IAEA, your information is not correct.
http://www.iaea.org/Publications/Factsheets/English/polonium210.html" onclick="window.open(this.href);return false;

Because Po-210 is produced from the decay of radon-222 gas, it can be found in the atmosphere from which it is deposited on the earth's surface. Although direct root uptake by plants is generally small, Po-210 can be deposited on broad-leaved vegetables. Deposition from the atmosphere on tobacco leaves results in elevated concentrations of Po-210 in tobacco smoke. There are tiny amounts of Po-210 in our bodies.

 

[Stoaty]

So you may ask, how in the world does radioactive Polonium get into a cigarette, right? It's because tobacco companies require growers to fertilize tobacco fields with a mineral Apatite, which natually contains radioactive Polinium. Apatite robs the plant of nitrogen and gives the tobacco leaf a desirable taste, which then makes you keep buying the product/brand, save for the nicotine addiction, of course.

Well, according to the IAEA, your information is not correct.
http://www.iaea.org/Publications/Factsheets/English/polonium210.html" onclick="window.open(this.href);return false;

This isn't entirely clear, there is evidence supporting ILETRIC's position. See J. Oncol., 2011, "Polonium and Lung Cancer":

"On the other hand, the majority of authors, such as Singh and Nilekani, have identified the importance of the fertilizers employed [74]. Calcium polyphosphates fertilizers are enriched with radium, which is chemically similar to calcium, and derive from soil that contains pitchblende and apatite [67, 75]. Interestingly, according to several studies, Indian cigarettes, which are made of scarcely fertilized tobacco, are 6 to 15 times less radioactive compared to the American ones, which derive from intensively fertilized plants [74]."

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3136189/" onclick="window.open(this.href);return false;

 

[planet4ever]

I would suggest that the OP rename this thread as "ILECTRIC's wild theories", except that since the OP is ILECTRIC he might not be inclined to do that. It certainly doesn't seem to have much to do with 2013 LEAF range, which is being discussed in the real 2013 thread, 2013 LEAF Specs, Pricing, Options Released In Japan.

Maybe a moderator should just move this thread to Off-Topic, where it seems to belong.

Ray

 

[ztanos]

Two comments:
1: Ilectric keeps saying that his 1 data point should be considered and then he neglects to consider other peoples arguments on pot and cancer because of 1 data point.

2: It would be rather hard to dictate what is giving cancer in cigarette smokers as many of the people who smoke pot also smoke cigarettes. So how can we say which actually gave them the cancer? We can't and since it is "illegal" in most states the patients will obviously not mention it and blame the cigarettes.

But back on topic:
I sure hope that the 2013 has better EPA range than what they are saying.

 

[nosuchthing]

Thank you for all the input. A spirited discussion is a good thing, no matter the outcome. It stimulates progress.

Anyway, I did my 60 miles yesterday and my sum of miles covered + GOM came out to 72 miles at the end of my journey.

Considering that I have made a few all-bubbles-on-board takeoffs, had to climb the 5-6 bubble Sausalito hill at 65 mph, and not counting the miles below GOM 3-4 (the three blinking lines) which usually amounts to at least 4 freeway miles before turtle, I am pleased to say that the car still shows no loss of range at 30,000 miles 18 months ownership.

Just for the record...

 

[Nubo]

Thank you all the input. A spirited discussion is a good thing, no matter the outcome. It stimulates progress.

Anyway, I did my 60 miles yesterday and my sum of miles covered + GOM came out to 72 miles at the end of my journey.

Considering that I have made a few all bubbles on board takeoffs, had to climb the 5-6 bubble Sausalito hill at 65 mph, and not counting the miles below GOM 3-4 (the three blinking lines) which usually amounts to at least 4 freeway miles before turtle, I am pleased to say that the car still shows no loss of range at 30,000 miles 18 months ownership.

For the record.

100% all the way!

Well then, keep stretching those Lithium tendons.

 

[DaveEV]

Anyway, I did my 60 miles yesterday and my sum of miles covered + GOM came out to 72 miles at the end of my journey.

Considering that I have made a few all bubbles on board takeoffs, had to climb the 5-6 bubble Sausalito hill at 65 mph, and not counting the miles below GOM 3-4 (the three blinking lines) which usually amounts to at least 4 freeway miles before turtle, I am pleased to say that the car still shows no loss of range at 30,000 miles 18 months ownership.

That doesn't tell us much unless you also report efficiency for that trip. Never mind that adding GOM to your distance traveled isn't necessarily a reliable indicator of how car you could have gone.

I drove 60 miles yesterday at 4.1 mi/kWh on a 80% +31 min/1.95 kWh L2, most of those miles at 65 mph, got home very close to VLBW (I power cycled the car with 4 mi on the GOM and the dash went to --- after the restart although the center console did not and I only got he regular LBW warning).

Assume that I could have gotten another 2 kWh into the battery had I waited for it to charge fully to 100% and I had 2 kWh remaining until turtle, I could have gotten 77 miles before draining it.

That comes to 18.9 kWh usable which is about 10% less than 21 kWh usable which should be available when new. Technically meets the range estimates in NTB11-076a, but I think we all know now that new cars perform at the upper end of the range.

 

[DeaneG]

...I drove 60 miles yesterday at 4.1 mi/kWh on a 80% +31 min/1.95 kWh L2...

Do we pretty much trust the dash cluster m/kWh reading (not the nav system m/kWh reading)? I've forgotten what we concluded on this.

 

[edatoakrun]

...I drove 60 miles yesterday at 4.1 mi/kWh on a 80% +31 min/1.95 kWh L2...

Do we pretty much trust the dash cluster m/kWh reading (not the nav system m/kWh reading)? I've forgotten what we concluded on this.

Despite quite a bit of evidence that both may be very inaccurate, many still seem to believe that it is useful to use these results.

AFAIK, the nav screen results will consistently match the dash m/kWh multiplied by ~1.025 (with stock tires and minimal tread-wear) but I don't believe either can be relied upon to accurately calculate actual kWh use.

 

[DaveEV]

Despite quite a bit of evidence that both may be very inaccurate, many still seem to believe that it is useful to use these results.

AFAIK, the nav screen results will consistently match the dash m/kWh multiplied by ~1.025 (with stock tires and minimal tread-wear) but I don't believe either can be relied upon to accurately calculate actual kWh use.

While there is definitely some variability in dash readings compared to wall readings, it's impossible to tell exactly where that variability is coming from.

Using data from my Blink to correlate wall mi/kWh to dash mi/kWh, my wall mi/kWh varies from 83-90% of the dash reading. But it's hard to say if that's due to the BMS stopping charging at slightly different charge levels or due to inaccuracies in the LEAF gauges or due to inaccuracies in the Blink kWh meter.

At the very least, one can average data to reduce the margin of error to a reasonable level.

Do you have a better idea?

 

[edatoakrun]

Despite quite a bit of evidence that both may be very inaccurate, many still seem to believe that it is useful to use these results.

AFAIK, the nav screen results will consistently match the dash m/kWh multiplied by ~1.025 (with stock tires and minimal tread-wear) but I don't believe either can be relied upon to accurately calculate actual kWh use.

While there is definitely some variability in dash readings compared to wall readings, it's impossible to tell exactly where that variability is coming from...

I think another major variable is battery temperature, which will effect both charge efficiency and available capacity.

And I still believe we also have not ruled out some (intentional or unintentional) BMS operation limiting charge percentage at "100%", determined by the battery packs use history.

drees:

...Using data from my Blink to correlate wall mi/kWh to dash mi/kWh, my wall mi/kWh varies from 83-90% of the dash reading. But it's hard to say if that's due to the BMS stopping charging at slightly different charge levels or due to inaccuracies in the LEAF gauges or due to inaccuracies in the Blink kWh meter.

At the very least, one can average data to reduce the margin of error to a reasonable level.

Do you have a better idea?

I believe that when you, and others make statements such as these:

drees:

...That comes to 18.9 kWh usable which is about 10% less than 21 kWh usable which should be available when new...

I believe you, and others, must acknowledge the large uncertainty in your estimates, when relying on data with these multiple large uncertainties.

So, this individual result above has an uncertainty range, of what, in your opinion? +/- 5% ? +/- 10% ?

Averaging would work if the variations were random, but not if the result of consistent over-reporting or under-reporting of kWh use by your LEAF.

The latter (recent consistent under reporting of kWh use, as compared to more accurate kWh use reports when near-new) seems to be the case for my LEAF, as indicated by multiple range tests from "100%" to LBW. But of course, I have no way to know if this is consistent with other LEAFs with similar usage histories.

...I chose a day with very close to the original temperature condition, and drove the exact same route over the first 87 miles of the trip, using the same mode (eco) and used my original trip logs to closely replicate the same elapsed times for each of the three (same distance) legs of the trip.

The results from 8/30/12 were:

97.3 miles to VLB, 98.9 miles in total, by the odometer.

CW: 96.5 (~2.5% under-report) total miles, at 5.7 m/kWh, 16.8 kWh used from 100% to about the same capacity level, slightly past VLBW.

Compare this test with my first test on 9/7/11:

91.5 miles to VLB, 93.4 in total, by the odometer

CW: 91.1 (~2.5% under-report) total miles, at 4.9 m/kWh, 18.7 kWh used from 100% to about the same capacity level, slightly past VLBW.

I do not believe that the slight increase in range over the last year reflects any increase in battery capacity. On the contrary, I expect that my total capacity ( though maybe not the amount of kWh that the BMS is allowing me to access) has declined by an undetermined amount, but it cannot be detected due to the “noise” of uncontrolled variables in a range test.

But I think the decrease of over 10% of reported kWh use, is simply too great to be consistent...

http://www.mynissanleaf.com/viewtopic.php?f=31&t=9064&start=20" onclick="window.open(this.href);return false;

And yes, the CW reports of m/kWh reported above were precisely matched by the dash reports, as they always do.

I can make no claim as to whether this test shows my LEAF has lost almost no capacity, or something closer to 10% of it's capacity over that year, since the many variables that remain in a range test, just like the variables in a measured charge result, probably impose a cumulative uncertainty of something close to 5% to 10%.

And, for the record, I think closely monitoring charge capacity will likely be the superior method to calculate actual available capacity loss in the future, as the variables will be more easily observed and controlled than for those in range tests, for those LEAFs with higher levels of capacity loss than your LEAF or mine presently have, where the actual loss of available capacity will be large enough to be more clearly observed above the multiple inaccuracies in measurement methods.

IMO, it is a major problem that the the dash, nav screen and CW kWh use reports seem to be so inaccurate, even while consistent between themselves. If we could rely on them, we would have a simple method to calculate both both initial battery capacity and loss over time.

I filed a complaint with Nissan about this months ago, but no others on this forum have done the same, AFAIK.

 

[DaveEV]

I believe that when you, and others make statements such as these:

drees:...That comes to 18.9 kWh usable which is about 10% less than 21 kWh usable which should be available when new...

I believe you, and others, must acknowledge the large uncertainty in your estimates, when relying on data with these multiple large uncertainties.

So, this individual result above has an uncertainty range, of what, in your opinion? +/- 5% ? +/- 10% ?

Every single range test I have performed in the last 6 months has calculated out to a usable 18.5-19.0 kWh. Wall charge data has also corroborated the data.

No where near 10%. Just a couple percent at most and remarkably consistent. For sure each one of those have been way more consistent than my daily dash mi/kWh to wall mi/kWh.

 

[edatoakrun]

I believe that when you, and others make statements such as these:

drees:...That comes to 18.9 kWh usable which is about 10% less than 21 kWh usable which should be available when new...

I believe you, and others, must acknowledge the large uncertainty in your estimates, when relying on data with these multiple large uncertainties.

So, this individual result above has an uncertainty range, of what, in your opinion? +/- 5% ? +/- 10% ?

Every single range test I have performed in the last 6 months has calculated out to a usable 18.5-19.0 kWh. Wall charge data has also corroborated the data.

No where near 10%. Just a couple percent at most and remarkably consistent. For sure each one of those have been way more consistent than my daily dash mi/kWh to wall mi/kWh.

I don't understand. What has the wall charge data "corroborated", if the dash m/kWh reports are inconsistent?

IOW, where do those "18.5-19.0 kWh" numbers come from?

If your wall charge data is that consistent, what is the ambient and estimated battery temperature range of your charges?

That doesn't sound too similar to what TickTock has reported, a much greater variation of ~19 kWh to ~22 kWh in "wall charge" data, if I understand him correctly:

https://docs.google.com/spreadsheet/ccc?key=0An7gtcYL2Oy0dHNwVmRkNkFnaEVOQTVENW5mOTZlb0E&pli=1#gid=3" onclick="window.open(this.href);return false;

The interesting thing I am seeing reported by many, is that the presumed lower capacity of cooler batteries does not seem to be reflected in "wall charge" data. This suggests to me (if the BMS is not varying the maximum charge level) that charging efficiency may much lower in cold batteries, as many reports (including my own) from range tests last winter, seemed to indicate significantly lower available battery capacity after charging colder batteries, in addition to the separate reductions in range from lower temperatures while driving.

So a lot of the kWh during winter charging, may just be heating up the battery packs, resulting in much lower charge efficiency. Knowing this amount of efficiency reduction at lower temperatures would allow you to more accurately calculate available capacity from the metered charge, right?

Of course, the same loss of available capacity should show up as shorter distances in subsequent temperature-adjusted range tests, correct?

 

[surfingslovak]

So a lot of the kWh during winter charging, may just be heating up the battery packs, resulting in much lower charge efficiency.

There is absolutely no evidence that this is happening.

Knowing this amount of efficiency reduction at lower temperatures would allow you to more accurately calculate available capacity from the metered charge, right?

Let me quote a friend, who worked as a systems lead on a well-known commercial EV: what ultimately matters is actual measured range and any other data or assumptions should be backed up by range tests. These can vary (even with access to a dyno), but if conducted methodically, significant trends will emerge.

Yes, our instrumentation and execution are not ideal. However, if a number of owners reports 10% range reduction, what is more likely? That their vehicles have indeed less range or that they are all misreporting due to an instrument error or some mysterious BMS behavior?

 

[TonyWilliams]

...I drove 60 miles yesterday at 4.1 mi/kWh on a 80% +31 min/1.95 kWh L2...

Do we pretty much trust the dash cluster m/kWh reading (not the nav system m/kWh reading)? I've forgotten what we concluded on this.

The Nav is 0.1 mile/kWh higher. We use the dash value (or just subtract 0.1 from the Nav).

 

[nosuchthing]

I have done this trip a few times before with the same result. The sum of my miles is all I look at to give me an idea what's going on reangewise. In fact, I keep looking calculating throughout my drives these days - ever since the AZ/TX range losses appeared on the horizon.

My lifetime is 3.7m/kW that usually goes down to 3.6 during winter due to heat use. Batt temp was at 5 bars at all times. Slovak is making a good point that charging capacity is temp dependent, and colder (not frozen) battery can take somewhat more charge than a hot one if I understan it correctly. Question is, how statistically significant it is.

I think that empirical observation of miles covered and remaining is perhaps the best dumbest method of determining range loss as it creeps in over time.

 

[TonyWilliams]

charging capacity is temp dependent, and colder (not frozen) battery can take somewhat more charge than a hot one if I understan it correctly.

A cold battery will not hold as much energy as the same battery when warmer.

A cold battery will charge more slowly, also, than the same battery when warmer.

A cold battery may also be limited on power over the same battery when warmer.

Hope this helps.