I personally am of the belief that predicting the capacity of a li-ion battery is something that is impossible to do outside of a battery manufactured in some *highly* controlled laboratory. All you can really predict is the general range of expected capacity. Seriously, the mechanisms of degrading are really complicated, and numerous. I honestly wouldn't worry too much about the capacity unless it starts dropping rapidly, or starts acting funny. I am doubtful that there is anything meaningful you can do with the clarity to make the battery last longer other than simply not using it, but take that with a grain of salt, as this is coming from someone who is completely unqualified in the field of battery chemistry and whatnot.
Budget Battery Capacity Readout
- Thread starter MrFixit
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MrFixit
Well-Known Member
In my mind, this exercise is not necessarily to 'predict' or optimize degradation (although some might believe that they can alter their usage in a way that does this). The main point for me is to give owners visibility into an extremely important parameter that is otherwise completely hidden (and could become a critical warranty item). Without some kind of visibility Honda holds all the cards (especially given that we have discovered that 'phantom' capacity resets can and do occur sometimes.
Also, although degradation effects may be complicated and unclear how they are affected, there is no doubt that usage cases DO impact degradation. If someone is considering purchasing a used Clarity, it would be important to know the remaining capacity because the previous owner could have 'abused' the HV battery (perhaps completely unknowingly).
Thanks for the disclaimer.
What possessed you to share your opinion on a subject for which, in your own words, you are “completely unqualified in the field”?
None of us are qualified as far as I know. Why are you so hostile?
rdav
Member
Do you happen to live on land? If so his username might give you a clue to that answer.
rdav
Member
Yeah I was just happy that it still had that much capacity left on it. I'll have to do a full test of EV only range for my area, but it was able to get me to work, back home, and then back to work with only depleting the battery to 2-3 bars under half. With each trip being just under 10 miles I am definitely happy with that performance. For a used buyer like myself its just another statistic to check when you are shopping, given you have choices at all given how rare these things are lol.
I simply asked a question, which by the way you didn’t answer. Then you asked a question. Here’s the answer to that. I do not consider my question to you, to be a question that was asked out of hostility. It was asked out of curiosity. I was curious why someone would voluntarily offer up an uninformed opinion when there is ample information available on the subject.
Do you also believe that the question was asked out of hostility?
rdav
Member
Not necessarily, but asking someone why they would share information on a forum is quite odd. I could see this being a legitimate question if you were in a room full of electrical engineers in a work environment, however here we are basically all speculating and sharing ideas related to the topic at hand. I fail to see why TC1782's post would warrant being questioned, let alone the disclaimer that is relevant to most, if not all posts on this thread.
I questioned why someone would share an “opinion” on a subject, which by their own admission they are unqualified to comment. I did not question the disclaimer, which appears to be accurate.
The post was a series of “opinions” that are largely inaccurate. We do know what causes battery degradation. It doesn’t take a PhD in the field to understand this. That said, not all forum members are as unqualified as you might like to believe. And if misinformation is allowed to go unchecked, we’ll all end up misinformed.
rdav
Member
Please quote and describe what he said as misinformation instead then instead of claiming things are "opinions" without saying what's incorrect about them. That is also a good part of why misinformation is so prevalent. After all if he is so abhorrently wrong it would be absolutely beneficial for the sake of this thread to point out the inconsistencies and correct them since you happen to know enough to say they are false, that also implies that you know the truth right?
As far as my understanding of lithium battery degradation goes, I don't see anything wrong with what he said. Please prove me wrong so that I can learn from this and others can as well.
I share my beliefs because I believe they might be interesting to some people, or at least contribute to the discussion. The science of batteries, like many things turn out to be, is a highly complicated multidisciplinary field. Unless someone forum member here has experience in the field of battery research, everything said here will more or less be speculation beyond some general statements like "more charge cycles cause the capacity to degrade". It's really damn easy to be an armchair engineer, and sometimes we can get pretty close to a solid understanding of some subjects. I probably have spent more than a thousand hours reading patents and scraping the Internet about the control system of I-MMD, and have recorded an immense amount of data from my car to verify conclusions, and have access to all the data tables on my cars ECU, so I can pretty confidentiality say I understood the general control system pretty well, but still not completely. Batteries are something that I simply can't read papers about without getting whapped on the head for not being a chemist, for example. That's why I say I'm unqualified and that my statements should be taken with a grain of salt when it comes to batteries. I could probably read a few books about it, and be a bit more educated, but these things are really complicated.
rdav
Member
I still find it funny that I don't see anything marked as disinformation as you claimed originally lol.
Even in the academic field of studying degradation of lithium ion batteries it is still very speculative about how each type of degradation works in conjunction with each other.
"With time and use, the storage capacity of LIBs diminishes and the internal resistance increases,12 due to a wide range of degradation mechanisms, some occurring simultaneously, or triggering further mechanisms. Some usage patterns and operating conditions lead to rapid degradation by one or more processes and the interplay between mechanisms is still not well understood."
This lends a lot of credibility to the highly controlled laboratory statement made previously, as those experiments are mostly in the study of one type of degradation and not the combined total of all degradation use cases. (Which is neigh impossible to test anyways.) This is done as it reduces the number of uncontrolled variables per test, unfortunately this leads to not a lot being known about the interactions between the various types of degradation.
The variables for the management and use of each lithium ion battery system is infinitely variable, it would take someone doing a case study on the specific scenario of the clarity given its parameters and battery management system to get a definitive answer. In order to get real use cases for this test, the best way to do that is to collect real world results, specifically around the Clarity, and analyze them...Oh wait I think I know a convenient place to find all that information. I'm sure it can be completely written off as a "Meaningless average"...
I'm fully willing to admit I'm definitely falling down the slope of Mt. Stupid on the Dunning Kruger graph after reading an academic paper regarding this subject during my lunch here at work. Here's a link for the paper that I skimmed through during my lunch. Good read tbh, might have to read it more closely after work as it is quite interesting.
https://pubs.rsc.org/en/content/articlehtml/2021/cp/d1cp00359c
All the knowledge in the world is still just our best guesses as to how the world actually works regardless of how much we, as a species, think we know.
By this logic, 2+2 no longer equals 4. And to think, some of us were convinced that we were in possession of some form of knowledge by believing that.
I originally said that the opinions were “largely inaccurate”. I later used the word “misinformation” while making a general statement. I did not use the word “disinformation” as you have incorrectly suggested.
You have provided misinformation about what I have said, unless there is intent to mislead, in which case you have provided disinformation.
Thanks for the reply.
There are 2 completely different positions being discussed. One is the feasibility of predicting battery degradation while the other is understanding what causes battery degradation.
I honestly, don’t know if anyone on this thread has proposed that degradation can be accurately predicted. Currently, there is a great deal of foaming at the mouth about how it can’t be predicted, when there is no indication that someone is saying that it can be predicted.
It’s a Straw Man argument.
rdav
Member
My apologies for my minor moment of dyslexia creating misinformation, good point to cherry pick.
Since we are on the topic of definitions here's a good one for you to check out as well.
https://www.logicallyfallacious.com/logicalfallacies/Appeal-to-Extremes
You, me and TC1782 have all agreed on the fact that its impossible to predict battery degradation, thus why I am not discussing that. Conveniently you using that as an attack against my argument sounds lot like using "...a distorted (and weaker) version of another person's argument that can easily be refuted."
I have to admit the dedication and thought put into making 4 different forum posts over the course of 17 hours and 4 minutes is quite commendable.
I'll refrain for hijacking this thread anymore after this as I believe my last post regarding battery degradation was the last useful item to be added since this disagreement began. It has been fun though!
Thanks for monitoring my forum activity. Perhaps commendations are in order for you, as well.
I’m retired and read some posts over morning coffee. There’s also time between, boating, fishing, golf, pickleball, car museums, sculpture gardens, etc.
I “cherry picked” your choice of a word because it was flat out, the wrong word and one that I hadn’t used or implied. I’ll accept your dismissal by dyslexia. That may be a clue.
My 2+2 remark was not to make a reasonable argument into an absurd one. It was to point out the absurdity of your statement about all knowledge being guesses. Perhaps misinformation, or disinformation has led you to that conclusion.
Why did you go to the effort to link a 3 1/2 year old article to support your position that predicting/estimating battery degradation is difficult if not impossible, if you feel that we are in agreement that battery degradation can’t be predicted?
Here’s a cherry pick from the article which explains that the purpose is to simplify the understanding of battery degradation. This has been my position from my post, that preceded your proclaimed useless posts, that we understand what causes battery degradation.
Lonewarrior
New Member
An update to the battery capacity
Now my car has 92200 miles and the capacity is 39.64