Lizard Pack Holding Up

aarond12 said:

... and at 4.4 miles/kWh, it says I have 89.9 miles to reserve. ...

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But what do you have the LSP reserve set to?
There are options of LBW, VLBW, or an adjustable kWh Remaining?
Also what are AHr, SOH, and Hx?

But does appear from the incomplete info you gave the heat resistant battery hasn't lost a lot in one year.

TimLee said:

But does appear from the incomplete info you gave the heat resistant battery hasn't lost a lot in one year.

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Haha! Proof positive I'm not a data junkie. I have the reserve settings at their defaults -- I haven't changed anything. The only thing I changed was my kWh/mile, which is at 4.4kWh/mile (lifetime average; I don't reset it). I'll see about digging up the other things you asked for.

This was also after sitting one day without charging, so maybe I'll run another test immediately after charging.

I wish I could be as optimistic as some of you are. My 2011 LEAF's battery was swapped at the end of April, so I have about 5-1/2 months of data thus far. Unfortunately, I didn't have a way to track degradation on the original battery until about 2014, so I don't know how quickly it was losing capacity, but looking at my data, it appears that I've already lost about 3.8 AHr (from 66.14 when new to 62.339 now). This represents almost a 6% drop in capacity in about 5-1/2 months, or a bit over 1% per month. If extrapolated, I'd be back down to 66% of capacity in about 34 months! Granted, this will likely not be the case, since the past few months have been the hottest months of the year.

It'll be interesting to see what the degradation will be at the one-year point. Hopefully many of us with "lizard" replacement batteries will contribute their findings to the forum so that we can get a better idea of just how much better the newer chemistry is.



BTW, here's the actual numbers (about 8,000 miles of driving):

• GIDs went from 278 to 270
• AHr went from 66.14 to 62.339
• SOH went from 100% to 97%
• Hx went from a high of 102.30 (about a week after the new battery was installed) to 93.66

It is funny, but for someone who will likely be buying a new pack out of pocket whether the pack holds up or not is good news. But somewhere in between - not so much.

thanks for the data. did you notice this Summer being as hot? I seem to remember 2011 being a real barnburner of a Summer, even moreso than your normal inferno... Either way, this is really big since Phoenix provides a much higher bar than anywhere else in the country

drees said:

Nissan's long capacity warranty on the new 30 kWh packs shows just how well they trust the 30 kWh chemistry over the 24 kWh lizard chemistry. You probably can still expect the lizard pack to lose 30% capacity not too long after 5 years / 60 k miles in the hottest climates.

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larger capacity, longer range = less cycles so an "equal" capacity warranty would be in reality a step down. However, time degradation is a factor especially in 2011's that are barely hitting 40,000 miles in optimal climates at 9 and 10 bars so adding years to the warranty is a good sign

TickTock, I understand your original pack's BMS was reset several times and it was showing 12 CBs for a couple of months despite significant capacity was already lost at that time. Looking at the chart in the OP your Gid readings were not affected by these resets and continued to track the actual energy stored in the pack, can you please confirm the resets did not in fact affect your Gids?

Valdemar said:

TickTock, I understand your original pack's BMS was reset several times and it was showing 12 CBs for a couple of months despite significant capacity was already lost at that time. Looking at the chart in the OP your Gid readings were not affected by these resets and continued to track the actual energy stored in the pack, can you please confirm the resets did not in fact affect your Gids?

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If you are talking about http://www.mynissanleaf.com/download/file.php?id=2175&mode=view

It looks like to me the GIDs jump from a reset at August 2012 and July 2013

dhanson865 said:

Valdemar said:

TickTock, I understand your original pack's BMS was reset several times and it was showing 12 CBs for a couple of months despite significant capacity was already lost at that time. Looking at the chart in the OP your Gid readings were not affected by these resets and continued to track the actual energy stored in the pack, can you please confirm the resets did not in fact affect your Gids?

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If you are talking about http://www.mynissanleaf.com/download/file.php?id=2175&mode=view

It looks like to me the GIDs jump from a reset at August 2012 and July 2013

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Ok, I see it, is this when his BMS was reset? I was thinking about jumps to 281 as if the BMS was thinking the pack was brand new right after reset. Was anything like that observed even for a very short duration? What about AHr, was it being tracked at the time?

Valdemar said:

Ok, I see it, is this when his BMS was reset? I was thinking about jumps to 281 as if the BMS was thinking the pack was brand new right after reset. Was anything like that observed even for a very short duration? What about AHr, was it being tracked at the time?

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Per the earlier thread:
http://www.mynissanleaf.com/viewtopic.php?f=31&t=18244&hilit=TickTock#p394179

SOH went to 100% and capacity bars went back to twelve and it took six months for SOH and capacity bars to go back to correct values.

Although GIDS were impacted, they were not grossly wrong like SOH and capacity bars.
They jumped about 7% to 10% erroneously high, for two months or more.

Not sure about the reported AHr.

From the earlier graph it looks like the clearing of long term capacity data was done August 2012 and July 2013.

I'm having a gid-related discussion elsewhere and someone who managed to reverse engineer the BMS firmware to the point of being able to know where the values are stored is claiming that the only parameter BMS knows that is directly related to the battery capacity is the SOH and the gids are directly calculated from it. It appears to be at least partially true based on the TickTock's tracking and reset history, but there must be some other correction algorithm which keeps the gids more or less in check should the actually capacity to be far off from the stored SOH. It does sound though that the AHr is basically SOH multiplied by some constant representing the initial known capacity.

Valdemar said:

I'm having a gid-related discussion elsewhere and someone who managed to reverse engineer the BMS firmware to the point of being able to know where the values are stored is claiming that the only parameter BMS knows that is directly related to the battery capacity is the SOH and the gids are directly calculated from it. It appears to be at least partially true based on the TickTock's tracking and reset history, but there must be some other correction algorithm which keeps the gids more or less in check should the actually capacity to be far off from the stored SOH. It does sound though that the AHr is basically SOH multiplied by some constant representing the initial known capacity.

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I don't think SOH and GIDs are related but AHr are GIDs are. My '15 has had 99% SOH but GID's have gone from 292 to 269 and AHr from 63 to 57.

LeafMuranoDriver said:

I don't think SOH and GIDs are related but AHr are GIDs are. My '15 has had 99% SOH but GID's have gone from 292 to 269 and AHr from 63 to 57.

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It looks like the SOH is taken into consideration when the LBC calculates Gids. One case I read about some degraded modules were swapped out with ones that had more capacity which totally screwed Gid readings, the owner reported that he could get 40 miles after LBW due to the stored SOH being lower than the actual, at least initially. The increased Gid count in the 2 instances when TickTock's LBC was reset also support this theory. Of course it doesn't affect anyone under normal conditions as SOH is being monitored and constantly updated by the LBC so it is the real number, but any disturbance like module replacement or SOH reset w/o replacing the battery will cause Gids to be reported incorrectly until the true SOH value is determined.

I have a suspicion that there is hidden capacity that is slowly used more and more, as the pack degrades giving us all an apparent illusion that there is no degradation during the first several months.

My 2014 manufactured and bought in Jan 14 stayed above 270 Gids for over 10k miles and 8 months and then decreased over the two summers to now at 235. I was delighted to see only marginal degradation during the first summer, only to be disappointed seeing a rapid decrease on the GIDs during the 2ndsummer (this summer) which was almost identical to the rate of degradation seen in my earlier 2011 model.

So the net effect is very little to no degradation the first year, followed by rapid degradation the subsequent years. I am now at 35k miles and 22 months into ownership with 235 Gids and lost one bar, although I think I should have lost 2 bars. At this rate I will lose by 4th bar only around 65-70K miles just enough to put me over the edge of not getting a free battery replacement.

Assuming this is what Nissan is doing for 2014 models by having a hidden reserve to put the owners just over the warranty period, that is quite a deceptive behavior.

The reason why i am stating this on a 2015 thread is that, we need to temper our enthusiasm and excitement over the initial reports from TickTock and others, and wait till we actually go through 3 or more summers to see how the 2015 battery pack holds up. I will reserve my judgement until then.

It has been long suspected newer packs have a larger hidden reserve. This is not necessarily bad news, if it helps to get a couple more years out of the pack. Heck, If it took 6 years and not 4 for me to lose 4 bars I'd probably be fairly satisfied.

For what its worth. I just hit 20K miles on my 2015 (mfg 4/14). My most recent reading. Granted its been much colder in CA lately.

275 Gids
21.31 kwh
97.03 SOC
88.34 SOH
90.11 HX
58.53 Ahr
65.4 degrees

I too believe that there's a few percent of hidden capacity there somewhere that gets eaten away the first year or so.

My 2015 lizard battery continues to degrade at the same rate as my 2011 battery. 7% SOH has been lost on each, so far, in less than a year. I honestly would have hoped that this would not be the results. I won't be able to track this much longer, as my 2011 with 9 bars, is at the brink of change out with 42.17AHr.

Evoforce said:

... I won't be able to track this much longer, as my 2011 with 9 bars, is at the brink of change out with 42.17AHr.

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Amazing that an Arizona 2011 LEAF with 37,000 miles hasn't already lost four capacity bars :?: :shock:

TimLee said:

Evoforce said:

... I won't be able to track this much longer, as my 2011 with 9 bars, is at the brink of change out with 42.17AHr.

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Amazing that an Arizona 2011 LEAF with 37,000 miles hasn't already lost four capacity bars :?: :shock:

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what is amazing is that he has two 2011 LEAFs per his signature but does not distinguish between the two. have to think he is referring to the one that has not had a lizard battery replacement which makes his comments OT or assume he is talking about the one that did have a replacement already which makes his comment a bit less amazing

TimLee said:

Amazing that an Arizona 2011 LEAF with 37,000 miles hasn't already lost four capacity bars :?: :shock:

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IIRC, he got both his '11 LEAFs used so they didn't necessarily live their full life in AZ.