Valdemar
Posts: 2672
Joined: Tue May 10, 2011 10:32 pm
Delivery Date: 09 Sep 2011
Location: Oak Park, CA

Re: Lizard Pack Holding Up

Sat Nov 07, 2015 10:43 am

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.
'11 SL, totaled
-1CB@33k/21mo, -2CB@53k/33mo, -3CB@68k/41mo, -4CB(41.5AHr)@79k/49mo, -5CB(38.85AHr)@87.5k/54mo
-0CB(66.14AHr)@87.5k/54mo (BBB), -1CB(53.92Ahr)@140k/29mo,
51.1AHr, SOH 80%, 150k miles

9kW Solar

LeafMuranoDriver
Posts: 351
Joined: Wed May 13, 2015 8:15 am
Delivery Date: 01 May 2015
Leaf Number: 323189
Location: Los Angeles, CA

Re: Lizard Pack Holding Up

Sat Nov 07, 2015 9:51 pm

Valdemar wrote: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.
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.
2015 Leaf S w/ QC
Mfg: Jan. '15 // Pur: May '15
Best: 6/27/15 - 1,416 Miles - 292 GIDs - 63.11 Ahr - 22.6 kWh - 100% SOH - 97.2% Hx - 4 QC, 29 L2
Worst: 12/12/15 - 4,616 Miles - 259 GIDs - 55.02 Ahr - 20.1 kWh - 99% SOH - 82.8% Hx - 17 QC, 96 L2[/size]

Valdemar
Posts: 2672
Joined: Tue May 10, 2011 10:32 pm
Delivery Date: 09 Sep 2011
Location: Oak Park, CA

Re: Lizard Pack Holding Up

Sat Nov 07, 2015 10:19 pm

LeafMuranoDriver wrote: 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.
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.
'11 SL, totaled
-1CB@33k/21mo, -2CB@53k/33mo, -3CB@68k/41mo, -4CB(41.5AHr)@79k/49mo, -5CB(38.85AHr)@87.5k/54mo
-0CB(66.14AHr)@87.5k/54mo (BBB), -1CB(53.92Ahr)@140k/29mo,
51.1AHr, SOH 80%, 150k miles

9kW Solar

mkjayakumar
Posts: 1219
Joined: Thu Mar 08, 2012 9:13 am
Delivery Date: 08 Mar 2012
Location: Plano, TX

Re: Lizard Pack Holding Up

Sun Nov 08, 2015 11:01 am

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.
2011 Leaf, 30K miles, returned after 24 month lease.
Currently leasing 2014 Leaf SV.

Valdemar
Posts: 2672
Joined: Tue May 10, 2011 10:32 pm
Delivery Date: 09 Sep 2011
Location: Oak Park, CA

Re: Lizard Pack Holding Up

Sun Nov 08, 2015 1:37 pm

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.
'11 SL, totaled
-1CB@33k/21mo, -2CB@53k/33mo, -3CB@68k/41mo, -4CB(41.5AHr)@79k/49mo, -5CB(38.85AHr)@87.5k/54mo
-0CB(66.14AHr)@87.5k/54mo (BBB), -1CB(53.92Ahr)@140k/29mo,
51.1AHr, SOH 80%, 150k miles

9kW Solar

tkdbrusco
Posts: 510
Joined: Sun Sep 07, 2014 9:46 am
Delivery Date: 31 Aug 2014
Contact: Website Facebook Twitter

Re: Lizard Pack Holding Up

Mon Nov 09, 2015 5:01 pm

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.
2015 Leaf S w/QC Package. San Jose, CA
www.theevconsultant.com

Evoforce
Posts: 924
Joined: Wed Mar 04, 2015 9:58 pm
Delivery Date: 28 Feb 2015
Location: Fountain Hills Arizona

Re: Lizard Pack Holding Up

Tue Nov 10, 2015 2:34 pm

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.
*2011 Leaf 1 bought 2/28/15 @ 28,000ish mi 10 bar (8 bars @ 11/25/15 @ 37,453 ) (New lizard @ 39,275 mi @ 1/20/2016) Now 52,166 mi.
*Tesla Model S 61,000 mi
*2011 Leaf 2 bought 4/28/15 @ 24,000ish mi 12 bar (new lizard Dec. 2014 @ 22,273 mi) Now 35,485 mi

TimLee
Posts: 2811
Joined: Thu Jan 20, 2011 9:40 am
Delivery Date: 17 May 2011
Leaf Number: 2026
Location: Chattanooga, TN

Re: Lizard Pack Holding Up

Wed Nov 11, 2015 4:59 am

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

Tim Lee
Chattanooga, TN

Man. Date: 03/10/11, VIN # 2026
Delivered 05-17-2011
Blue Ocean, 2011 SL-eTec

DaveinOlyWA
Posts: 15643
Joined: Sat Apr 24, 2010 7:43 pm
Delivery Date: 16 Nov 2019
Leaf Number: 319862
Location: Olympia, WA
Contact: Website

Re: Lizard Pack Holding Up

Wed Nov 11, 2015 7:55 am

TimLee wrote:
Evoforce wrote:... 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.
Amazing that an Arizona 2011 LEAF with 37,000 miles hasn't already lost four capacity bars :?: :shock:
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
2011 SL; 44,598 mi, 87% SOH. 2013 S; 44,840 mi, 91% SOH. 2016 S30; 29,413 mi, 99% SOH. 2018 S; 25,185 mi, SOH 92.23%. 2019 S Plus; 19,653 mi, 93.47% SOH
My Blog; http://daveinolywa.blogspot.com" onclick="window.open(this.href);return false;

User avatar
DaveEV
Posts: 6251
Joined: Fri Apr 23, 2010 3:51 pm
Location: San Diego

Re: Lizard Pack Holding Up

Wed Nov 11, 2015 10:49 am

TimLee wrote:Amazing that an Arizona 2011 LEAF with 37,000 miles hasn't already lost four capacity bars :?: :shock:
IIRC, he got both his '11 LEAFs used so they didn't necessarily live their full life in AZ.

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