DaveinOlyWA
Posts: 13134
Joined: Sat Apr 24, 2010 7:43 pm
Delivery Date: 16 Feb 2018
Leaf Number: 314199
Location: Olympia, WA
Contact: Website

Re: Long Term Reliability of the 30kWh Battery Pack

Sat Jun 16, 2018 8:25 am

coupedncal wrote:
edatoakrun wrote:
DaveinOlyWA wrote:


How do we propose we do this? Use LeafSpy type tool?

I am confused by this apparent fix from Nissan as even the LeafSpy tool was reporting lower values and thereby implying the battery storage capacity was dropping rapidly on these 30 kWh models. Am I correct with this statement? This fix will resolve the dashboard inaccuracies but wasn't LeafSpy tapping the batteries directly and LeafSpy did not use the input from the dash?


Small point of clarification; The dashboard displays were likely accurate. Well as accurate as you can be when using invalid data I guess. The error is basically at the very foundation of the battery pack itself so EVERYTHING is potentially affected.


LEAF Spy only parrots what it sees on the bus. So any miscalculation would be passed on. The real concern is what other changes will happen with the correct calculations?

Realize it is possible that the BMS allowed the pack to charge to full speed up to 80% SOC (something ONLY the 30 kwh pack does thru out the entire industry) because of bad info it was receiving from the LBC.

So fix the info and now the BMS starts ramping down the charge at 63% SOC like the 40 kwh pack did (24 kwh pack ramped down earlier)


A possibly good analogy (any analogy requires being on the same plane of thought)

You are in Detroit, Michigan and want to navigate to 123 Baker St, Detroit, Michigan.

So you get directions from the NAV but the NAV doesn't realize its in Detroit, Kansas navigating to 123 Baker St, Detroit, Kansas. It only knows you must travel in a specific direction for a specific distance and then turn right...
2011 SL; 44,598 miles. 2013 S; 44,840 miles.2016 S30 deceased. 29,413 miles. 2018 S40; 8743 miles, 485 GIDs, 37.6 kwh 111.39 Ahr , SOH 96.49, Hx 114.98
My Blog; http://daveinolywa.blogspot.com" onclick="window.open(this.href);return false;

johnlocke
Posts: 278
Joined: Fri Jan 08, 2016 3:47 pm
Delivery Date: 14 Dec 2015
Leaf Number: 300582

Re: Long Term Reliability of the 30kWh Battery Pack

Sat Jun 16, 2018 9:20 am

edatoakrun wrote:
DaveinOlyWA wrote:
edatoakrun wrote:So, nissan says that after the update, the capacity bar display will now be "accurate".

Forgive me, but has Nissan ever stated what "accurate" capacity each bar represents?

All Nissan was ever willing to say about the "24 kWh" pack capacity, was that four bars lost represented approximately 30% of new capacity.


The bars will not change. They are simply a representation of the state of the car. They are NOT to be considered as digital representations of anything ...

Yes, and the same can be said for the grossly inaccurate LBC estimates of battery capacity, which are used to inform the bar displays.

Unfortunately, most "30 kWh" pack LEAF owners seem to have been just as willing to make fools of themselves, as most "24 kWh" pack owners have over the years, when they took LBC data seriously as accurate data on pack capacity.

So, with is campaign, Nissan will now change the LBC readings on "30 kWh" packs, allegedly to make them less inaccurate, just like it claimed it was trying to do for our "24 kWh" LEAFs.

That effort was a failure, as the higher-capacity LBC readings soon drifted back to ~the same level of extreme inaccuracy, as confirmed by recharge and range tests on my LEAF and others' at the time.

But, maybe this time it will be different?

If any of you "30 kWh" pack owners want to find out, I suggest you try to learn what you have neglected to learn to date, how to monitor your pack capacity accurately, using objective methods, and entirely ignoring the garbage data from your LBC, and that you do so before you accept Nissans "corrective" campaign.

Your strategy is flawed. No matter how you measure the battery capacity, you are limited to Nissan's information as to the state of the battery. Even you run the battery to "turtle" and carefully measure the power used to recharge, you are limited to Nissan's evaluation of both turtle and 100% charged. It doesn't matter if the BMS is giving false information because short of pulling the battery out of the car and bench testing it you are limited to what the BMS says the state of the battery is. If you accept that battery voltage is directly comparable to state of charge then unless the BMS is falsely interpreting the battery voltage these batteries are losing capacity. While I haven't specifically checked for a change in the voltage level at low charge levels (I.E. LBW, VLBW) I also haven't noticed any real variation either. Since I now have a new battery I can't check the voltages at LBW or VLBW on a degraded battery. Perhaps someone else could do it and report their findings.
2016 SV, New battery at 45K mi.
Jamul, CA
San Diego East County

jbuntz
Posts: 137
Joined: Thu Dec 08, 2016 5:41 am
Delivery Date: 17 Dec 2016
Leaf Number: 303765
Location: New Braunfels, TX

Re: Long Term Reliability of the 30kWh Battery Pack

Mon Jun 18, 2018 6:11 pm

30kWh at turtle with 8 bars

min/avg/max 3.426/3.456/3.494

before reset AHr=50.51 SOH= 63.55 Hx=60.59%

Temp F = 106.9 106.7 105.3
Mfg 11/15 Del 12/16 TX 2016 SL 30kWh,
Date Bar MI GID Ahr SOH
05/17 12 05175 324 70.75 89
08/17 11 09245 282 61.68 77
10/17 10 12000 260 57.22 71
01/18 09 15329 244 53.72 68
06/20 08 21716 230 50.41 63
06/27 11 22047 296 66.01 83 Aftr Updt

Return to “General / Main Owners Forum”