TonyWilliams
Well-known member
palmermd said:DarkDave said:... Tony's range chant...
Freud?
I do that, but only late at night.
palmermd said:DarkDave said:... Tony's range chant...
Freud?
Ingineer said:Personally, and as an experienced EV Engineer, I agree with Nissan for choosing passive cooling. I do not think in the future we will see much active cooling for EV battery systems.
The chemistry will improve so as to be more heat tolerant, and the problems we have now will disappear!
If Nissan had installed active cooling, the Leaf would be heavier, have less range, and be significantly more costly. In addition, Active cooling requires power, which means it must be plugged in most of the time or even more drastic range reduction will occur.
Keep in mind, it's not actually proven there is much actual degradation! I believe it's a combination of a small amount of degradation combined with instrumentation errors (failures), and that once Nissan corrects the software in the LBC (Battery ECU), apparent "lost" capacity will return. Let's at least give them time to fix this before condemning them!
Just because a Leaf owner cannot drive as far, doesn't mean the battery has a fault. The LBC determines all charging and discharging limits, and if it's being "overprotective" like I suspect, once they correct this, range will magically return. If it doesn't, Nissan will fix it. Regardless, I'm convinced Andy was sincere and Nissan is going to make this right.
-Phil
Ingineer said:Personally, and as an experienced EV Engineer, I agree with Nissan for choosing passive cooling. I do not think in the future we will see much active cooling for EV battery systems.
I agree with what you said here, Phil, from the technical perspective that the lack of TMS may not necessarily be a bad thing.Ingineer said:Personally, and as an experienced EV Engineer, I agree with Nissan for choosing passive cooling. I do not think in the future we will see much active cooling for EV battery systems.
The chemistry will improve so as to be more heat tolerant, and the problems we have now will disappear!
If Nissan had installed active cooling, the Leaf would be heavier, have less range, and be significantly more costly. In addition, Active cooling requires power, which means it must be plugged in most of the time or even more drastic range reduction will occur.
Keep in mind, it's not actually proven there is much actual degradation! I believe it's a combination of a small amount of degradation combined with instrumentation errors (failures), and that once Nissan corrects the software in the LBC (Battery ECU), apparent "lost" capacity will return. Let's at least give them time to fix this before condemning them!
Just because a Leaf owner cannot drive as far, doesn't mean the battery has a fault. The LBC determines all charging and discharging limits, and if it's being "overprotective" like I suspect, once they correct this, range will magically return. If it doesn't, Nissan will fix it. Regardless, I'm convinced Andy was sincere and Nissan is going to make this right.
-Phil
I think I did say essentially this many months ago in another thread!edatoakrun said:I wish you could have written that six months ago, Phil.
Am I wrong to suspect you wouldn't have said "...it's a combination of a small amount of degradation combined with instrumentation errors..." without LEAFSCAN results tending to support it?
myleaf said:Ingineer said:Personally, and as an experienced EV Engineer, I agree with Nissan for choosing passive cooling. I do not think in the future we will see much active cooling for EV battery systems.
The chemistry will improve so as to be more heat tolerant, and the problems we have now will disappear!
-Phil
I agree, active cooling always seemed like a bandaid to me.
But from the town hall meeting it seems that heat tolerant battery chemistries will not be available (at Nissan) in the near future
While I'd like to believe that because I want the LEAF to succeed, it remains to be seen whether or not Nissan will actually have a more heat resistant chemistry for MY 2015. I hope that you turn out to be correct.LEAFfan said:There will be a much different BC for the LEAF MY 2015.
Based on what's being discussed, it looks like we can break it down into 3 areas of capacity loss:Ingineer said:I think I did say essentially this many months ago in another thread!edatoakrun said:I wish you could have written that six months ago, Phil.
Am I wrong to suspect you wouldn't have said "...it's a combination of a small amount of degradation combined with instrumentation errors..." without LEAFSCAN results tending to support it?
Unfortunately I haven't been able to get LEAFSCAN™ on any Phoenix cars, so that's not any source of information for me. Clearly, if you just look at all the results and what people are actually seeing, there are a lot of discrepancies. Nissan has even somewhat hinted that there are instrumentation issues, which is what I originally suspected.
In any event, To confirm my theories, I'd have to actually do some lab tests on the battery pack, not just take LEAFSCAN™ readings, as they are only as good as the data the LBC reports. I think the LBC definitely needs some software changes, and I bet Nissan is working on this right now. Keep in mind it takes a while to do this kind of work, test it thoroughly, then get it out to the dealers and issue the service campaign. They've told us this spring. Sounds about right to me!
-Phil
dgpcolorado said:Might not do those of us with older cars much good since a new chemistry would mean a new BMS, even if the format of the new cells was compatible with the current pack layout, and that might be impractical. Sure would be nice though.
That depends on what you consider "much", since Nissan's own testing of some of the Phoenix Leafs found remaining capacities of 85% and lower. For such a short period of time, and without proper disclosure up front by Nissan, I would say that is quite a bit. However, in all but the hottest areas you are probably correct.Ingineer said:Keep in mind, it's not actually proven there is much actual degradation! I believe it's a combination of a small amount of degradation combined with instrumentation errors (failures), and that once Nissan corrects the software in the LBC (Battery ECU), apparent "lost" capacity will return. Let's at least give them time to fix this before condemning them!
Thank you, that's exactly the point I wanted to raise. Nissan performed a battery bench test in Casa Grande in July, and shared the results with affected owners. I wouldn't necessarily call 14 or 15% capacity loss in 1 1/2 years minimal, but that's a question of semantics. It would be good to keep things in perspective though. While a lot of attention has been given to capacity loss, local climate, and the inherent properties of the battery chemistry used in the LEAF, I believe that Nissan has not acknowledged how inadequate instrumentation can compound the problem and rob owners of even more range. Note that some of them reported a subjective loss of autonomy between 20% to 30%. That's significantly more than could be expected based on battery degradation alone. I think this is one of the reasons why owners might feel that a warranty based on capacity bars alone is not enough to remedy the situation.Stoaty said:That depends on what you consider "much", since Nissan's own testing of some of the Phoenix Leafs found remaining capacities of 85% and lower. For such a short period of time, and without proper disclosure up front by Nissan, I would say that is quite a bit. However, in all but the hottest areas you are probably correct.Ingineer said:Keep in mind, it's not actually proven there is much actual degradation! I believe it's a combination of a small amount of degradation combined with instrumentation errors (failures), and that once Nissan corrects the software in the LBC (Battery ECU), apparent "lost" capacity will return. Let's at least give them time to fix this before condemning them!
A range test is NOT conclusive, since range depends on the LBC (battery ECU) allowing a full normal charge, and then allowing a full normal discharge. It may very well not being allowing full access to the "ends", which I have seen supporting evidence for. For instance if it erroneously "thinks" the battery is somehow degraded, it may limit charging/discharging, or both resulting in artificially reduced range.Volusiano said:Based on what's being discussed, it looks like we can break it down into 3 areas of capacity loss:
1. True capacity loss due to heat exposure.
2. Perceived capacity loss due to instrumentation error.
3. Upfront capacity loss (more like untapped built-in capacity) due to conservative margins set by Nissan.
While 2 and 3 can be fixed with better software by Nissan, 1 is real, permanent, and can't be fixed by Nissan using software. 1 is also not by a "small" amount, as evident by Tony's Phoenix range test showing that it's real and it's significant enough.
Ingineer said:Again, (I keep saying this) I don't truly know what's going on, but I've definitely seen enough weird numbers to be convinced there's a good possibility that there is some problem with the LBC not allowing access to the whole capacity. This may well be due to SOME real degradation, but it may also be "over-reacting" and restricting a lot of still real usable capacity because of these errors.
-Phil
surfingslovak said:If the LBC, related software or instrumentation can have such a profound effect on the autonomy, wouldn't this give more credence to calls for a true range warranty? From an owner perspective, it does not really matter, if it's battery degradation or perhaps some other defect, which is restricting the range of the vehicle.
I would agree, except this is hard to test for because of the time involved and the wide variance. You'd pretty much need to transport the car to a specific test track (or duplicate them all over the country) and drive it with a fixed profile. Really hard to quantify!surfingslovak said:If the LBC, related software or instrumentation can have such a profound effect on the autonomy, wouldn't this give more credence to calls for a true range warranty? You see, from an owner perspective, it matters little, if it's battery degradation or perhaps some other defect, that's restricting the range of the vehicle. I believe Tony made that point earlier last year, and this was one of the motivations for the range test on September 15.
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