igxqrrl
Posts: 5
Joined: Thu May 16, 2019 8:23 am
Delivery Date: 16 May 2019

Re: Chaotic Range Readings from 40 kWh 2018 SV

Sat Aug 03, 2019 6:12 pm

cwerdna wrote:
Fri Aug 02, 2019 8:19 pm
LeftieBiker wrote:
Fri Aug 02, 2019 7:48 pm
Yep. I didn't see a link to a LeafSpy shot.
igxqrrl wrote:
Fri Aug 02, 2019 4:08 pm
I took a screenshot of Leafspy which appears to be showing one cell that has a lower voltage than the rest https://imgur.com/a/cCLHNm5
I haven't watched the video but yes, that's bad. It shouldn't be like that when the car's nearly full.

Have the dealer run a CVLI test. It will fail. NO way there should be 200+ mV imbalance when the car's nearly full.
Thanks for this -- that's my belief as well. I showed that picture to the dealer and he seemed completely non-plussed by it. He said the correct way to test the battery is to run it down to about 10%, and then test it. He said when they did that, it tested correctly (or within spec at least).

My contention is any time 95 cells have voltage "x", and 1 cell has voltage of "0.9x", there is something wrong.

The trouble of course is getting the dealer to acknowledge that!

igxqrrl
Posts: 5
Joined: Thu May 16, 2019 8:23 am
Delivery Date: 16 May 2019

Re: Chaotic Range Readings from 40 kWh 2018 SV

Sat Aug 03, 2019 6:15 pm

Tortoisehead77 wrote:
Fri Aug 02, 2019 4:53 pm
My 2018 Leaf behaves that way sometimes, although not quite as drastic. The guess-o-meter is significantly off, usually.

I just drove to the Oregon Coast today and at around 40% remaining, the % started dropping rapidly. It’s important to note that this occurred during descent!! I should have been gaining miles using the e-pedal, not losing miles. As a approached 10 miles from the Chademo charger in Lincoln City, I started gaining a significant amount of miles, but not % of battery.

As a rule of thumb, I estimate a loss of 1% per mile, and this method has never left me stranded.
I'm in Oregon as well. I've found that when it gets into its "drop quickly" mode, it also "regains quickly" during regen, which is different than the symptom you saw. I actually suspect if I were willing to continue driving at 15%, I'd probably get an additional 40 miles at that point, because clearly there is energy in the battery, just that the computer isn't recognizing it, presumably because of the low voltage in the bad cell.

But this means that, with anything under 30% or so, I can't get in the car and have any idea how much range is remaining. Could be a bunch, could be a little. Kinda like having a new car where the gas gauge is non-functional!

igxqrrl
Posts: 5
Joined: Thu May 16, 2019 8:23 am
Delivery Date: 16 May 2019

Re: Chaotic Range Readings from 40 kWh 2018 SV

Sat Aug 03, 2019 6:16 pm

LeftieBiker wrote:
Fri Aug 02, 2019 5:41 pm
If there is a problem, it's likely a bad cell or two - marginally bad, not enough to throw a code yet. There have been a significant number or 40kwh packs with this issue. What is the build date on the driver's side door sill?
Interesting to hear this. I've seen another video on youtube that had a similar pattern. My build date is 04/18. The car did sit on the lot (in hot central-Oregon weather) for a year or so before I bought it, so I've wondered if that caused the problem. Though if so I'd expect more than one cell to be affected.

igxqrrl
Posts: 5
Joined: Thu May 16, 2019 8:23 am
Delivery Date: 16 May 2019

Re: Chaotic Range Readings from 40 kWh 2018 SV

Sat Aug 03, 2019 6:21 pm

Flyct wrote:
Fri Aug 02, 2019 7:45 pm
Looking at your LeafSpy pix you have a bad cell.



Image
Out of curiosity (I'm new to Leafspy -- just got it after observing this issue), do you generally expect all the cells to lose voltage at the same rate? After driving for a while, half my cells still show full voltage, and half have dropped significantly. The dropped/full are interleaved (i.e. 1,3,5,...,95 are low, and 2,4,6,..,96 are still full).

I've been wondering if the pack is logically divided into two halves, and the one with the bad cell is not being used because the computer is trying to balance the two halves.

See:
https://imgur.com/a/4mxsRuH

Image


Thanks!
Last edited by igxqrrl on Sat Aug 03, 2019 6:24 pm, edited 1 time in total.

cwerdna
Posts: 9670
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Location: SF Bay Area, CA

Re: Chaotic Range Readings from 40 kWh 2018 SV

Sat Aug 03, 2019 6:22 pm

Sorry. I wish I could be of more help. Maybe Googling for site:mynissanleaf.com cvli will turn up something helpful.

viewtopic.php?f=30&t=18468 had no luck (I actually know him and have talked to him in person years later). His car ended up with this guy who did succeed in getting his dealer to replace the bad module: viewtopic.php?f=9&t=21700. The voltage values will likely be different on 40 kWh Leaf though. But still, the amount of imbalance you were seeing at high SoC is NOT normal.

'19 Bolt Premier
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LeftieBiker
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Re: Chaotic Range Readings from 40 kWh 2018 SV

Sat Aug 03, 2019 7:06 pm

I've been wondering if the pack is logically divided into two halves, and the one with the bad cell is not being used because the computer is trying to balance the two halves.


No. The Battery Management System (BMS) uses the lowest cell voltage as the controlling input when it comes to allowable voltage. IOW, when the weakest cell reads low, the BMS assumes that the pack is low. To put it a third way, the pack is only as strong as the weakest cell.
Scarlet Ember 2018 Leaf SL W/ Pro Pilot
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Tortoisehead77
Posts: 61
Joined: Fri Jun 14, 2019 9:59 am
Delivery Date: 31 May 2018
Leaf Number: 307925
Location: Portland, Oregon USA

Re: Chaotic Range Readings from 40 kWh 2018 SV

Sat Aug 03, 2019 7:15 pm

igxqrrl wrote:
Sat Aug 03, 2019 6:15 pm
Tortoisehead77 wrote:
Fri Aug 02, 2019 4:53 pm
My 2018 Leaf behaves that way sometimes, although not quite as drastic. The guess-o-meter is significantly off, usually.

I just drove to the Oregon Coast today and at around 40% remaining, the % started dropping rapidly. It’s important to note that this occurred during descent!! I should have been gaining miles using the e-pedal, not losing miles. As a approached 10 miles from the Chademo charger in Lincoln City, I started gaining a significant amount of miles, but not % of battery.

As a rule of thumb, I estimate a loss of 1% per mile, and this method has never left me stranded.
I'm in Oregon as well. I've found that when it gets into its "drop quickly" mode, it also "regains quickly" during regen, which is different than the symptom you saw. I actually suspect if I were willing to continue driving at 15%, I'd probably get an additional 40 miles at that point, because clearly there is energy in the battery, just that the computer isn't recognizing it, presumably because of the low voltage in the bad cell.

But this means that, with anything under 30% or so, I can't get in the car and have any idea how much range is remaining. Could be a bunch, could be a little. Kinda like having a new car where the gas gauge is non-functional!
This is good to know. Thanks!

Flyct
Posts: 260
Joined: Tue Nov 03, 2015 12:04 am
Delivery Date: 02 Dec 2015
Leaf Number: 307113
Location: Bradenton, Florida, US

Re: Chaotic Range Readings from 40 kWh 2018 SV

Sat Aug 03, 2019 10:23 pm

I’ve owned 3 Leafs now. A 2015 24 kWh, a 2018 40 kwh and currently a 2019 62 kWh. I’ve never seen LeafSpy voltage spread like yours.

Here’s a screenshot of my 2015 24 kWh Leaf

Image

Here’s the 2028 40 kWh Leaf

Image

And here’s my current 62 kWh Leaf Plus

Image
Last edited by Flyct on Sun Aug 04, 2019 6:39 am, edited 2 times in total.
2019 Leaf SL Plus w/All Options
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LeftieBiker
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Re: Chaotic Range Readings from 40 kWh 2018 SV

Sat Aug 03, 2019 11:20 pm

The 2015 is a 24kwh Leaf. The 30kwh pack was offered beginning in the 2016 model year, IIRC. Or are you referring to the build month?
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.

Flyct
Posts: 260
Joined: Tue Nov 03, 2015 12:04 am
Delivery Date: 02 Dec 2015
Leaf Number: 307113
Location: Bradenton, Florida, US

Re: Chaotic Range Readings from 40 kWh 2018 SV

Sun Aug 04, 2019 6:40 am

LeftieBiker wrote:
Sat Aug 03, 2019 11:20 pm
The 2015 is a 24kwh Leaf. The 30kwh pack was offered beginning in the 2016 model year, IIRC. Or are you referring to the build month?
You're correct. I fixed it.
2019 Leaf SL Plus w/All Options
2015 Lexus RX450h Hybrid SUV
2019 Ford F-350 Lariat Ultimate Crew Cab Short Bed Diesel
2017 Grand Design Reflection 337RLS 5th Wheel RV
2017 Kawasaki FXT-Pro LE Side by Side
Blissfully Retired and loving it!

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