coulomb
Posts: 65
Joined: Thu Oct 09, 2014 5:08 pm
Delivery Date: 07 Mar 2015
Leaf Number: 200445
Location: Brisbane, Australia

Re: Leaf range after battery module replacement

Sun Oct 13, 2019 3:33 am

Lothsahn wrote:
Sat Oct 12, 2019 11:18 pm
By high, I meant 75% (as shown in the picture). The slope of the curve is rather flat there--especially compared to the bottom 10% of the battery.
Ah. The last 10% is "off the cliff", which I assume we (and Nissan) are staying away from.
Between 10 and 50 Ah, the voltage changes .3V, but that covers 72% of the capacity of the battery.
Actually, I read 0.5V (2.5 divisions of 0.2V each). That's about 0.5/3.65*100% = 14% of nominal voltage. I would not call that "flat". I agree that is it flat relative to the cliff, but I assume that the cliff is off-limits. Am I wrong assuming that the cliff is off-limits?
2012 Leaf with new battery May 2019. New to me June 2019.

Lothsahn
Posts: 516
Joined: Thu Apr 05, 2018 4:35 pm
Delivery Date: 04 Jan 2018
Leaf Number: 007797

Re: Leaf range after battery module replacement

Sun Oct 13, 2019 11:32 am

coulomb wrote:
Sun Oct 13, 2019 3:33 am
Lothsahn wrote:
Sat Oct 12, 2019 11:18 pm
By high, I meant 75% (as shown in the picture). The slope of the curve is rather flat there--especially compared to the bottom 10% of the battery.
Ah. The last 10% is "off the cliff", which I assume we (and Nissan) are staying away from.
Between 10 and 50 Ah, the voltage changes .3V, but that covers 72% of the capacity of the battery.
Actually, I read 0.5V (2.5 divisions of 0.2V each). That's about 0.5/3.65*100% = 14% of nominal voltage. I would not call that "flat". I agree that is it flat relative to the cliff, but I assume that the cliff is off-limits. Am I wrong assuming that the cliff is off-limits?
Ah crud. I misread 3.9 as 3.7. You are right. .5V.

That said, you and I are saying the same thing with different terms. :) What I call flat, you're calling not flat. I think the primary reason is I was trying to illustrate that when at VLBW/Turtle in a Leaf, the voltage differences are huge (because you are off the cliff), whereas when it's charged, they're not. On the other hand, your experience is with other chemistries and potentially power regulators (where a .5V difference is significant). In short: Large = off cliff, Small=the normal section of the curve between cliff and 4.1V.

The assumption that Nissan is staying away from "off the cliff" is a good one, but unfortunately, not correct. To maximize range, Nissan does in fact allow cells to go quite low--here's a few posts on turtle voltage, seeing 3.2V and potentially even lower:
viewtopic.php?t=14143#p321871

Keep in mind that those posts are about the 24kWh Leaf, which has a different voltage curve than the one we've been looking at for the 40 kWh cells:
https://qnovo.com/wp-content/uploads/20 ... harge2.gif
(you can see the cliff starts at 3.4-3.6V, depending on current draw)

This is why it's critical to immediately charge the leaf if you ever get to VLBW or Turtle--you've already started down the cliff, and it's not good to leave the cells at that low SOC for long.
2011 Silver SV, purchased 2018, lives in Missouri (previously in CA)
LeafSpy Pro + BAFX Products OBDII dongle
Battery swap 2019/04/24 (87% SOH, 12 bar)

coulomb
Posts: 65
Joined: Thu Oct 09, 2014 5:08 pm
Delivery Date: 07 Mar 2015
Leaf Number: 200445
Location: Brisbane, Australia

Re: Leaf range after battery module replacement

Sun Oct 13, 2019 5:53 pm

Lothsahn wrote:
Sun Oct 13, 2019 11:32 am
That said, you and I are saying the same thing with different terms. :)
Ok, I think we understand and agree with each other now (other than the meaning of "flat", but flatness is a relative thing). Thanks for your patience with me.
2012 Leaf with new battery May 2019. New to me June 2019.

johnlocke
Posts: 445
Joined: Fri Jan 08, 2016 3:47 pm
Delivery Date: 14 Dec 2015
Leaf Number: 300582

Re: Leaf range after battery module replacement

Sun Oct 13, 2019 7:36 pm

On my old 30KWH battery you could indeed "drive off the cliff" going below 340 volts (about 18% charge remaining) to about 317 VDC at 3% remaining. I haven't tested the new battery to see if there were any changes.
2016 SV, New battery at 45K mi.
Jamul, CA
San Diego East County

rmay635703
Posts: 533
Joined: Wed Jan 19, 2011 7:43 pm

Re: Leaf range after battery module replacement

Sun Oct 13, 2019 8:19 pm

Makes you wonder if the slowest possible L1 charge rate would help

gary65536
Posts: 3
Joined: Thu Sep 21, 2017 9:59 pm

Re: Leaf range after battery module replacement

Tue Oct 15, 2019 2:33 pm

I really appreciate all the advice and discussion on this issue. I took the car back to the dealership to have them take a look. They did not see any problem and did not see any problem with cell imbalance. It's not clear how they checked the balancing. The advisor explained that if there was a significant imbalance it would throw a diagnostic code, as the car did when the battery leak happened originally. So I fear that they just relied upon diagnostic codes and didn't do any more in depth measurement. I asked what could be causing the range loss if its not due to cell imbalance. No good answer, but the advisor did say the next step would be for me to report the issue to Nissan's regional support.

I'm going to drive the car until a low SOC and then do a L1 or L2 charge back up to 100%. Based on the discussion in this thread it doesn't sound like that will balance the cells much, but it will enable me to (1) Get an updated cell voltage read out from LeafSpy at different SOC levels to aid my understanding of the concepts discussed in this thread, and (2) Allow me to log the miles driven, KWh used, battery percentage and remaining range reported through a whole discharge cycle. I think this will be important data to make my case to Nissan, along with LeafSpy cell voltage read out from LeafSpy if Nissan would consider looking at that information.

Thanks again - I'll keep this thread updated.

LeftieBiker
Moderator
Posts: 13300
Joined: Wed May 22, 2013 3:17 am
Delivery Date: 30 Apr 2018
Location: Upstate New York, US

Re: Leaf range after battery module replacement

Tue Oct 15, 2019 10:26 pm

The advisor explained that if there was a significant imbalance it would throw a diagnostic code, as the car did when the battery leak happened originally. So I fear that they just relied upon diagnostic codes and didn't do any more in depth measurement.

This is the equivalent of saying "Your car isn't running hot - the red light doesn't come on!" Diagnostic codes are like idiot lights, just available in greater numbers. LeafSpy (especially the Pro version) is more like a gauge cluster on the dashboard.
Scarlet Ember 2018 Leaf SL W/ Pro Pilot
2009 Vectrix VX-1 W/18 Leaf modules, & 3 EZIP E-bicycles.
BAFX OBDII Dongle
PLEASE don't PM me with Leaf questions. Just post in the topic that seems most appropriate.

DaveinOlyWA
Posts: 14160
Joined: Sat Apr 24, 2010 7:43 pm
Delivery Date: 16 Nov 2019
Leaf Number: 319862
Location: Olympia, WA
Contact: Website

Re: Leaf range after battery module replacement

Thu Oct 17, 2019 7:10 am

gary65536 wrote:
Tue Oct 15, 2019 2:33 pm
I really appreciate all the advice and discussion on this issue. I took the car back to the dealership to have them take a look. They did not see any problem and did not see any problem with cell imbalance. It's not clear how they checked the balancing. The advisor explained that if there was a significant imbalance it would throw a diagnostic code, as the car did when the battery leak happened originally. So I fear that they just relied upon diagnostic codes and didn't do any more in depth measurement. I asked what could be causing the range loss if its not due to cell imbalance. No good answer, but the advisor did say the next step would be for me to report the issue to Nissan's regional support.

I'm going to drive the car until a low SOC and then do a L1 or L2 charge back up to 100%. Based on the discussion in this thread it doesn't sound like that will balance the cells much, but it will enable me to (1) Get an updated cell voltage read out from LeafSpy at different SOC levels to aid my understanding of the concepts discussed in this thread, and (2) Allow me to log the miles driven, KWh used, battery percentage and remaining range reported through a whole discharge cycle. I think this will be important data to make my case to Nissan, along with LeafSpy cell voltage read out from LeafSpy if Nissan would consider looking at that information.

Thanks again - I'll keep this thread updated.
About what I expected from them. On your drive, I would make sure you have a charger near by when you get below 25% SOC. Those low cells will be quite unpredictable and may trigger Turtle. If that happens and you are not within a mile of a charger, then power down immediately and wait maybe 20 mins or so. This will equalize cells. You may have to disconnect 12 volt battery to remove Turtle alert. If you have LEAF Spy "Pro", clearing codes should do it as well.
2011 SL; 44,598 miles. 2013 S; 44,840 miles.2016 S30 deceased. 29,413 miles. 2018 S40; 25,185 miles SOH 92.23%
My Blog; http://daveinolywa.blogspot.com" onclick="window.open(this.href);return false;

nlspace
Posts: 67
Joined: Mon Jun 05, 2017 10:21 pm
Delivery Date: 06 Jun 2017

Re: Leaf range after battery module replacement

Thu Oct 17, 2019 7:40 am

How has the max-min difference progressed? Has it gotten smaller or larger after several days of driving and charging up to full? The leafspy is your best tool to track whether or not it is balancing itself back closer together.

Lothsahn
Posts: 516
Joined: Thu Apr 05, 2018 4:35 pm
Delivery Date: 04 Jan 2018
Leaf Number: 007797

Re: Leaf range after battery module replacement

Thu Oct 17, 2019 9:01 am

gary65536 wrote:
Tue Oct 15, 2019 2:33 pm
I really appreciate all the advice and discussion on this issue. I took the car back to the dealership to have them take a look. They did not see any problem and did not see any problem with cell imbalance. It's not clear how they checked the balancing. The advisor explained that if there was a significant imbalance it would throw a diagnostic code, as the car did when the battery leak happened originally. So I fear that they just relied upon diagnostic codes and didn't do any more in depth measurement. I asked what could be causing the range loss if its not due to cell imbalance. No good answer, but the advisor did say the next step would be for me to report the issue to Nissan's regional support.

I'm going to drive the car until a low SOC and then do a L1 or L2 charge back up to 100%. Based on the discussion in this thread it doesn't sound like that will balance the cells much, but it will enable me to (1) Get an updated cell voltage read out from LeafSpy at different SOC levels to aid my understanding of the concepts discussed in this thread, and (2) Allow me to log the miles driven, KWh used, battery percentage and remaining range reported through a whole discharge cycle. I think this will be important data to make my case to Nissan, along with LeafSpy cell voltage read out from LeafSpy if Nissan would consider looking at that information.

Thanks again - I'll keep this thread updated.
Did they do the cell imbalance check at the VLBW (---) on the dash or did they just check it at the current battery level? If not checked at VLBW, that's why it didn't throw codes. You may need to inform them on the proper procedure for how to, you know, do basic diagnostic stuff they should know.

<sarcasm>I'm SHOCKED that the dealership that didn't do the repair properly also doesn't know the procedures to detect if the repair was done wrong. </sarcasm>

I agree collecting more data is a good idea for you to do.

I will get the appropriate lines from the service manual tonight, although it'll be 2011, not your model year. Hopefully that will give you more ammunition. to deal with them.

It would also be useful to keep a video of the dash, in case your car goes to turtle prematurely. If you can show the dealership that your car goes to turtle when it shouldn't, that gives you an additional problem for the dealership to justify.
2011 Silver SV, purchased 2018, lives in Missouri (previously in CA)
LeafSpy Pro + BAFX Products OBDII dongle
Battery swap 2019/04/24 (87% SOH, 12 bar)

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