DaveinOlyWA
Well-known member
Agreed because it provides peace of mind like the engine on a Volt but battery capacity restricted to only be used when real dead weight of a degraded batery pack happens is never as good as breakeven
You claim this idea is a "myth"? We can all read about it in a feature article written by Lyle at GM-Volt.com which he begins by writing:scottf200 said:Yes, it is sort of a myth that likes to gets repeated here on MNL. There was a comment made in an interview to that affect as I recall but nothing remotely official.Volusiano said:I've started following the GM-Volt forum for the last 3 months and I get the impression that nobody over there knows whether GM made plan to eat into the extra capacity over the long run or not to preserve the advertised range of about 40 miles.
Hmm, the article is from the Chevrolet Volt launch event. That sounds official to me.Lyle at GM-Volt.com said:At the recent Chevrolet Volt launch GM finally let the skeletons out of the closets and exposed all of the Volt’s closely guarded secrets.
So, what do you think, did Lyle imagine that someone at GM said this, or did someone at GM imagine that this is really how the Chevy Volt works? Both of those possibilities seem pretty remote to me considering I cannot think of any other EV BMS which does this.Lyle at GM-Volt.com said:As the battery ages and energy storage capacity of the lithium-ion cells degrades, control units will widen the percent state of charge band to continue to deliver the range goal.
That statement seems to confirm exactly the operation of the Volt that Lyle reported.scottf200 said:After 21K EV miles in my 2011 it has not appeared to lose any range. 30 winter, 45 summer (2011/12-EPA 35, 2013-EPA 38).
It seems that DashDAQ used to report total battery capacity, but that parameter was removed back in 2011. I wonder why.scottf200 said:The ~22% to ~87% SOC has been shown in DASHDAQs and it will be interesting to see what the ELR shows.
That's good they are confident in their battery system. IMO, they should be. It seems very well-engineered.scottf200 said:Multiple GM comments indicate they are using more of the battery. That bodes well for thier confidence.
I would have been very pissed off if Nissan had required us to haul around dead weight which is the reason I did not purchase the Volt because that is what the Volt is doing.
Do you believe everything every Jack and Jill or Lyle post on a forum as "gospel"? Is Lyle an official GM spokesman? Or just a poster on a forum who wrote a feature article? Did Lyle quote any GM official for saying that they do expand the band if capacity is lost?RegGuheert said:You claim this idea is a "myth"? We can all read about it in a feature article written by Lyle at GM-Volt.com which he begins by writing:scottf200 said:Yes, it is sort of a myth that likes to gets repeated here on MNL. There was a comment made in an interview to that affect as I recall but nothing remotely official.Volusiano said:I've started following the GM-Volt forum for the last 3 months and I get the impression that nobody over there knows whether GM made plan to eat into the extra capacity over the long run or not to preserve the advertised range of about 40 miles.
Hmm, the article is from the Chevrolet Volt launch event. That sounds official to me.Lyle at GM-Volt.com said:At the recent Chevrolet Volt launch GM finally let the skeletons out of the closets and exposed all of the Volt’s closely guarded secrets.
In his report, Lyle writes the following:So, what do you think, did Lyle imagine that someone at GM said this, or did someone at GM imagine that this is really how the Chevy Volt works? Both of those possibilities seem pretty remote to me considering I cannot think of any other EV BMS which does this.Lyle at GM-Volt.com said:As the battery ages and energy storage capacity of the lithium-ion cells degrades, control units will widen the percent state of charge band to continue to deliver the range goal.That statement seems to confirm exactly the operation of the Volt that Lyle reported.scottf200 said:After 21K EV miles in my 2011 it has not appeared to lose any range. 30 winter, 45 summer (2011/12-EPA 35, 2013-EPA 38).It seems that DashDAQ used to report total battery capacity, but that parameter was removed back in 2011. I wonder why.scottf200 said:The ~22% to ~87% SOC has been shown in DASHDAQs and it will be interesting to see what the ELR shows.That's good they are confident in their battery system. IMO, they should be. It seems very well-engineered.scottf200 said:Multiple GM comments indicate they are using more of the battery. That bodes well for thier confidence.
Do you have something remotely official that indicates that Lyle's report is incorrect? If not, do you have some compelling evidence that this is NOT actually how the Chevy Volt operates. If so, please post it. If not, I will continue to believe that the battery in the Chevy VOlt does, in fact, degrade with time and use in spite of the fact that your available energy and miles do not go down.
I haven't kept up with gm-volt.com, but Lyle was the original creator of that forum. He got (I think) the very first Volt. He was never employed by GM, but did have many interactions with Volt designers and implementers, and was given a good deal of inside information. Lyle is no "Jack or Jill".Volusiano said:Do you believe everything every Jack and Jill or Lyle post on a forum as "gospel"? Is Lyle an official GM spokesman? Or just a poster on a forum who wrote a feature article? Did Lyle quote any GM official for saying that they do expand the band if capacity is lost?
Lyle may be no Jack or Jill, but Lyle is no GM official either.planet4ever said:I haven't kept up with gm-volt.com, but Lyle was the original creator of that forum. He got (I think) the very first Volt. He was never employed by GM, but did have many interactions with Volt designers and implementers, and was given a good deal of inside information. Lyle is no "Jack or Jill".Volusiano said:Do you believe everything every Jack and Jill or Lyle post on a forum as "gospel"? Is Lyle an official GM spokesman? Or just a poster on a forum who wrote a feature article? Did Lyle quote any GM official for saying that they do expand the band if capacity is lost?
Ray
Sorry, that does not make it a myth. It still stands as the very best explanation of how the Chevy Volt manages its battery.Volusiano said:There's nothing wrong with calling it a myth because GM never officially confirms this and only 1 non-GM source said this.
Wow, even GM said on their own warranty statement that users should expect 10-30% capacity loss during the 8 years 100K miles warranty. So who said anything about Volt batteries not losing any capacity with time and use???RegGuheert said:Sorry, that does not make it a myth. It still stands as the very best explanation of how the Chevy Volt manages its battery.Volusiano said:There's nothing wrong with calling it a myth because GM never officially confirms this and only 1 non-GM source said this.
The myth is the idea that Chevy Volt batteries do not lose capacity with time and use.
Because they are in a competitive marketplace and they consider this fact to be a trade secret. The fact that owners like you believe that the TMS prevents battery degradation is good marketing, as well.Volusiano said:If they did, why wouldn't they advertise that fact to their advantage as a marketing point, instead of still cautioning users to expect up to 30% loss?
It's not just good marketing when just about every other manufacturers except for Nissan chose to do TMS even though it raises their cost of manufacturing. It's not good marketing but actually good engineering. Mitsubishi is the only other company that doesn't do TMS, but due to the same reason that Nissan doesn't do it, to keep the cost down.RegGuheert said:The fact that owners like you believe that the TMS prevents battery degradation is good marketing, as well.
Trading off cost for capability is a very reasonable design decision.Volusiano said:It's not just good marketing when just about every other manufacturers except for Nissan chose to do TMS even though it raises their cost of manufacturing. It's not good marketing but actually good engineering. Mitsubishi is the only other company that doesn't do TMS, but due to the same reason that Nissan doesn't do it, to keep the cost down.RegGuheert said:The fact that owners like you believe that the TMS prevents battery degradation is good marketing, as well.
Yes, but I don't think they believe a TMS can prevent battery degradation, only that it reduces it in hot climates. So far, the Chevy Volt has shown NO reduction in available capacity or range regardless of age or miles even though it has the smallest battery of the lot. You seem to believe this is due solely to the TMS. I contend that the BMS is what makes this possible. And don't get me wrong: I think this is a very clever approach for the BMS.Volusiano said:As far as what owners choose to believe, we have seen plenty of LEAF owners, even not in hot climate like in CA (like TomT) who publicly said that they'll never ever buy another EV without TMS anymore. Tony Williams (who lives in CA, too) abandoned the LEAF for a RAV4 EV which has TMS.
Note that the battery in the Volt is 1/3 the size of the battery in the RAV4EV and 1/5 the size of the battery in the Model S. Also note that the battery in the Volt uses a chemistry very similar to the chemistry in the LEAF which is much less capable of handling heat than that used in the RAV4EV and Model S. In those vehicles the combination of a big battery, a better battery chemistry and TMS reduce battery degradation to very low levels. The Volt has the TMS, which can help it in hot climates, but it has the drawback of a small battery and a less robust chemistry. So GM chose to use a BMS technique to both reduce battery degradation earlier in life AND hide degradation from their owners.Volusiano said:On the other hand, we have not seen a single owner of the Volt or Tesla or Rav4 EV say that they wish their car didn't come with TMS after all. And this is not just new buyers, but owners who have lived with their TMS EVs for at least 2 years so far.
They have only been duped if they believe TMS prevents battery degradation. I doubt they believe that. But I think they feel it is the best option for their application.Volusiano said:So you can call these owners naive and being duped by good marketing all you want. I call them sensible owners who learned through their own experience (of having a TMS or not having a TMS on their EV) the value of TMS.
="RegGuheert"
...It still remains to be seen if TMS provides much benefit in other locations. It certainly has drawbacks. Cost is one of them...
Agreed. If you are going to sell the car in a wide range of climates with the current battery technology, then TMS makes good sense.Volusiano said:But obviously all these trade-offs are deemed well worth it at this point by most manufacturers in light of the lack of maturity in battery technology to have a more heat resistant chemistry.
And for me, today, the TMS/smaller battery combination does not look good. Perhaps Nissan is focused on the long-term rather than the short term. The question is whether or not they will create so much bad will that they will not make it to the long term with their approach.Volusiano said:We're not debating the merits of TMS 5 or 10 years down the road. We're only debating the merits of TMS today in face of the current infancy of immature battery technology.
Volusiano said:....We're not debating the merits of TMS 5 or 10 years down the road..
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