Yanquetino
Well-known member
- Joined
- May 11, 2010
- Messages
- 479
For anyone interested, I have posted a Capacity Loss Tool. Hope some will find it useful.
Yanquetino said:For anyone interested, I have posted a Capacity Loss Tool. Hope some will find it useful and reassuring.
Thanks for catching those typos! I've corrected them, and also changed the temperatures to F. I had simply copied-and-pasted them from Nissan's page, but it's true that not specifying the type of degrees could confuse owners overseas. Good suggestion!richard said:Checking out your tables now. FYI, Scenarios 4 and 5 show Speed as "mpg" instead of "mph". Also, would be clearer if the temperatures specified F or C.
Hi, George:surfingslovak said:Mark, commendable effort. I would have couple of comments as well. The 83% charge is actually an 80% charge, which was confirmed by Phil as well. Also, the usefulness of your charts would increase, if you dropped the month/mileage reference, and only retained the battery state of health percentage. I'm pretty sure that the mileage-to-degradation projection does not apply to everyone. My Leaf was down 10% after 15K miles in a temperate California climate last time I looked. A friend asked his dealership to get a readout, and they confirmed 9% after 19K miles in a similar climate.
Thanks, Richard! That's a good suggestion. I might also render the info in a PDF format, once I verify specifics like the 80% vs. 83% issue that George pointed out.richard said:Mark,
Looking over the tables, I think these could be among the most important resources for would-be buyers to gauge whether the LEAF is for them (and to let current drivers benchmark their own car). I encourage you to get them into PDF format and post them directly to your top post here. At least the EPA driving cycle one. Or, if it can be presented clearly, maybe all the driving cycles can be different columns in a single chart?
Thanks,
Richard
Yanquetino said:For anyone interested, I have posted a Capacity Loss Tool. Hope some will find it useful and reassuring.
Hi, LEAFfan: Mmm, no: that "yellow box" isn't from an owner's manual --either old or new. It is from the actual disclosure form I had to sign to take delivery of my Leaf last March. I assume that the 2011 disclaimer is the same...? Check your copy and let me know, okay?LEAFfan said:Just wanted to let you know that you have posted info from the old owners' manual (yellow box). QCing more than once a day is NOT harmful to the battery pack. The new manual states that multiple QCs are okay. People need to know the truth so they can freely use this wonderful technology.
Actually, it's both simpler and more complicated than that. CarWings is saying 83% (or 75%) because the only data it gets is "ten bars" (or "nine bars"), so no rounding is involved. This is clearly silly logic, since when you have 0 bars it says you have 0%. In fact you may have up to 15% at that time. But Phil said "80%" is really 80% of current total capacity, not usable capacity. By a curious coincidence that works out to be about 83% of usable capacity.Yanquetino said:'Tis true that the Charge Timer control panel gives us the option of 100% or 80% (recommended), but when I do use the 80% option, CarWings always tells me that my pack is now charged to 83%, i.e., 10 of 12 bars. I thus put 83% since that's what (I assume?) other users also see with those notifications, and I didn't want to confuse them. I mean, it is true that 10/12 = 83.34%. Is Phil stating that the setting really does shut off at 80%, but CarWings is "rounding up" the 10th bar to display a slightly exaggerated 83%? If so... sure misleading, and only exacerbates the impression of range loss another 3%!
Well put, that's absolutely correct. However, there is no such thing as an 83% charge, and I believe that it's potentially confusing to readers. I would nix it for the sake of clarity.planet4ever said:By a curious coincidence that works out to be about 83% of usable capacity.
Tsk. Yes, it sure sounds simpler yet more complicated! In this case... if the 83% displayed via CarWings really is "83% of usable capacity," wouldn't it be better for me to calculate and list those ranges in my capacity tables? I would imagine that owners would want to know what capacity (range) they could conceivably USE, if need be... wouldn't they?planet4ever said:Actually, it's both simpler and more complicated than that. CarWings is saying 83% (or 75%) because the only data it gets is "ten bars" (or "nine bars"), so no rounding is involved. This is clearly silly logic, since when you have 0 bars it says you have 0%. In fact you may have up to 15% at that time. But Phil said "80%" is really 80% of current total capacity, not usable capacity. By a curious coincidence that works out to be about 83% of usable capacity.Yanquetino said:'Tis true that the Charge Timer control panel gives us the option of 100% or 80% (recommended), but when I do use the 80% option, CarWings always tells me that my pack is now charged to 83%, i.e., 10 of 12 bars. I thus put 83% since that's what (I assume?) other users also see with those notifications, and I didn't want to confuse them. I mean, it is true that 10/12 = 83.34%. Is Phil stating that the setting really does shut off at 80%, but CarWings is "rounding up" the 10th bar to display a slightly exaggerated 83%? If so... sure misleading, and only exacerbates the impression of range loss another 3%!
Ray
Tony, based on Nissan info referenced above which Yanquetino has extrapolated to a linear decrease, I think you should change the degradation modifier on your Range chart to at least 3%/10,000 miles, or 10%/30,000 miles. The former is a slight understatement, the latter a slight overstatement. And add a note to double, triple, quadruple or quintuple it depending on summer temperatures.TonyWilliams said:>>>>Nissan estimates that the capacity might drop to approximately 80% after 5 years (or 62,500 miles) and 70% after 8 years (or 100,000 miles).<<<<<
Since all that data is from Nissan's already generic public data, I see only extrapolating imperfect data, which is less enlightening. It doesn't reflect real life, which does not reflect 70/80% in 5/10 years in Phoenix, for instance in the 100F scenario.
If you had included Nissan's much more recent data of 7500 mile duty cycle years in that 100 degree scenario, and forecasted the more likely scenario of hitting 60,000 miles in 5 years equals at 12,000 miles per year, the actual Nissan data would suggest:
60,000 / 7500 = 8 year degradation data in Phoenix in 5 calendar years. Further, the data has been reindexed, again by Nissan, to 76% in 5 year/7500 mile per year data. The result averages 4.8 % per 5 calendar years using 8 "Nissan-LEAF-Years(TM)" years with 7500 miles per year.
In addition, not indicating a 10% loss the first year is blatantly misleading. You mentioned it, but didn't follow through. Since we must reduce the first year by 10%, subsequent years would then equal 3.4% reduction per NLY. With 8 NLYs in a normal driver's 5 year/12,000 mile driving experience in Phoenix, the final results based on Nissan's data (and not their consumer public data) is:
Year 1 = 90% [100% - 10% first year loss]
Year 2 = 84.56% [90% - (3.4% * (8/5))]
Year 3 = 79.12% [84.56% - (3.4% * (8/5))]
Year 4 = 73.68% [79.12% - (3.4% * (8/5))]
Year 5 = 68.24% [73.68% - (3.4% * (8/5))]
Year10= 41.04% [68.24% - 5(3.4% * (8/5))]
That's just Nissan's formerly secret data applied to the US government statistical 12,000 mile per year driver in Phoenix. This does not impart seasonal losses that must be added to battery capacity in winter (additional 10% loss at 30F, in addition to cabin heater losses (which can be small or quite significant, based on comfort level, preheating, electric seat/steering use, et al).
Winter time available capacity at 30F/0C and one hour of 2kW heating (sorry, running late, can't do proper formula... Estimations):
Year 1 = 80% - 2kWh
Year 2 = 74.56% - 2kWh
Year 3 = 69.12% - 2kWh
Year 4 = 63.68% - 2kWh
Year 5 = 58.24% - 2kWh
Year10= 31.04% - 2kWh
Mark, you are going through the same motions and mistakes several of us went through already. If you cared to have a look, I created a table, which predicts remaining battery capacity and range based on the charging time display. 80% charge clearly shows more than 80% usable capacity. Although the table is dynamic, I did not consider rapid capacity loss when I created it. Likewise, I did not think that LBW and VLBW would be fixed, and not just a percentage of a degraded pack. It's also worth noting that the charging time display exhibits a number of idiosyncrasies, which would be roughly consistent with the performance of other instruments in the car.Yanquetino said:Tsk. Yes, it sure sounds simpler yet more complicated! In this case... if the 83% displayed via CarWings really is "83% of usable capacity," wouldn't it be better for me to calculate and list those ranges in my capacity tables? I would imagine that owners would want to know what capacity (range) they could conceivably USE, if need be... wouldn't they?
I doubt that these numbers apply to climates other than Phoenix. Mark seemed determined to prove that the situation there was 'normal'. If you applied the same formula to Steve Marsh up in Kent, then he would be down more than 15% based on mileage alone, which would not account for calendar life degradation. I can name a number of vehicles out in the field, where this simple approach won't work. There are few of us that tried to come up with lifecycle predictions, and failed. That's why I would caution anyone to jump to premature conclusions and broadcast them far and wide.GRA said:Tony, based on Nissan info referenced above which Yanquetino has extrapolated to a linear decrease, I think you should change the degradation modifier on your Range chart to at least 3%/10,000 miles, or 10%/30,000 miles. The former is a slight understatement, the latter a slight overstatement. And add a note to double, triple, quadruple or quintuple it depending on summer temperatures.
GRA said:Tony, based on Nissan info referenced above which Yanquetino has extrapolated to a linear decrease, I think you should change the degradation modifier on your Range chart to at least 3%/10,000 miles, or 10%/30,000 miles. The former is a slight understatement, the latter a slight overstatement. And add a note to double, triple, quadruple or quintuple it depending on summer temperatures.
My condolences. Very sad to hear of your loss.TonyWilliams said:My 23 year old son used to maintain the website with the range chart, but he passed away this summer, and I don't really have the desire to rebuild it.
surfingslovak said:I doubt that these numbers apply to climates other than Phoenix.
Mark, you are going through the same motions and mistakes several of us went through already.... Mark seemed determined to prove that the situation there was 'normal'.... That'a why I would caution anyone not to jump to premature conclusions and broadcast them far and wide.
+100. Yeah. Sorry to hear about that. That's way too young an age to die.Stoaty said:My condolences. Very sad to hear of your loss.TonyWilliams said:My 23 year old son used to maintain the website with the range chart, but he passed away this summer, and I don't really have the desire to rebuild it.
cwerdna said:+100. Yeah. Sorry to hear about that. That's way too young an age to die.Stoaty said:My condolences. Very sad to hear of your loss.TonyWilliams said:My 23 year old son used to maintain the website with the range chart, but he passed away this summer, and I don't really have the desire to rebuild it.
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