MikeinPA
Well-known member
Very interesting! "dealer put my dashboard back incorrectly such that I wasn't able to set it to full heat."
[help] Rapid battery discharge, "limited motor power", and sporadic power output at temp. < 30F and > 40% motor power.
- Thread starter twilsonco
- Start date
Help Support My Nissan Leaf Forum:
That sounds reasonable. I should have several more cold spells in which to observe this condition occurring at higher SOC's (in the above example it happened at ~45%), and perhaps resulting in both greater cell voltage differences and pack voltage fluctuations.
I expect you're right that having a tech in the car with me is the way to go. My local dealer is positioned right at the bottom of a 15mi long hill with a 65MPH speed limit. In fact the route I'll use in my testing is exactly their test drive route, so having it fail to complete their own route will make it harder for them to maintain their "yep, it's seven years old, so what do you expect?" stance. If I can't obtain convincing data or DTCs then I'll make my case from a safety standpoint.
I think I'll use the python framework I wrote to generate these plots to make an interactive dashboard for more easily experimenting with different plot combinations, and with a "replay" mode that lets you step through all the instantaneous data you see in LeafSpy, with your position shown on a map for good measure
If that ever gets done I'll share it with the forum.
On another note:
I promise this is the only time I'll do this.
And thanks. My day job is currently as a theoretical chemistry researcher, developing software for a new type of computational electron charge density analysis. Real cool stuff; we've identified a general (works everywhere) method for identifying precise chemical bonding regions, enabling the apples to apples comparison of bonds in any chemical system, so you can qualitatively and quantitatively compare the bonds in, say, an enzyme vs those in iron. So I'm used to trying to intuit my way around multidimensional data.
Edit: That said, the only reason I can think more freely about the dynamics of a Leaf battery now is from this forum. Before posting here I spent a few hours trying to familiarize myself with the battery system with a broader search through the internet and even li-ion scientific literature and felt like I was getting nowhere. This is simply an amazing community here and I'm very grateful to have such a resource. So thanks!
Since I can't stop typing; the bigger challenge in my research is finding ways to guide the reader through 1-, 2-, and 3-d visualizations that all correspond to the same 3-d space. Check out my thesis defense, full of kickass animations and visualizations, where I do my best to make what we've accomplished accessible to a general audience. Here's a link to a youtube playlist (https://youtube.com/playlist?list=PL0s2a65tbuC3bGlh5VlD6lmkkMgMucIw4) where the first video is the (Zoom) defense itself. I wrote the code for all the animations, which were rendered in a program called Tecplot 360.
Here's the defense, if you want to hear actual explanations rather than just pretty slides
https://youtu.be/AV2a3V2A-Hk
Here's a 2-minute introduction to the topological structure of the electron charge density in ethylene.
https://youtu.be/5tgcJ0JpDzo
Then here's a way to decompose the electron charge density into an conceptually infinite number of regions with "well-defined" energies (which isn't true for an arbitrary region)
https://youtu.be/HKlEc6mD6uQ
Lastly, here's what that process looks like with ethyl alcohol, and how the result can be used to identify the unique chemical bonding regions
https://youtu.be/TfXNVdlE2NE
I expect you're right that having a tech in the car with me is the way to go. My local dealer is positioned right at the bottom of a 15mi long hill with a 65MPH speed limit. In fact the route I'll use in my testing is exactly their test drive route, so having it fail to complete their own route will make it harder for them to maintain their "yep, it's seven years old, so what do you expect?" stance. If I can't obtain convincing data or DTCs then I'll make my case from a safety standpoint.
I think I'll use the python framework I wrote to generate these plots to make an interactive dashboard for more easily experimenting with different plot combinations, and with a "replay" mode that lets you step through all the instantaneous data you see in LeafSpy, with your position shown on a map for good measure
If that ever gets done I'll share it with the forum.On another note:
I promise this is the only time I'll do this.
And thanks. My day job is currently as a theoretical chemistry researcher, developing software for a new type of computational electron charge density analysis. Real cool stuff; we've identified a general (works everywhere) method for identifying precise chemical bonding regions, enabling the apples to apples comparison of bonds in any chemical system, so you can qualitatively and quantitatively compare the bonds in, say, an enzyme vs those in iron. So I'm used to trying to intuit my way around multidimensional data.
Edit: That said, the only reason I can think more freely about the dynamics of a Leaf battery now is from this forum. Before posting here I spent a few hours trying to familiarize myself with the battery system with a broader search through the internet and even li-ion scientific literature and felt like I was getting nowhere. This is simply an amazing community here and I'm very grateful to have such a resource. So thanks!
Since I can't stop typing; the bigger challenge in my research is finding ways to guide the reader through 1-, 2-, and 3-d visualizations that all correspond to the same 3-d space. Check out my thesis defense, full of kickass animations and visualizations, where I do my best to make what we've accomplished accessible to a general audience. Here's a link to a youtube playlist (https://youtube.com/playlist?list=PL0s2a65tbuC3bGlh5VlD6lmkkMgMucIw4) where the first video is the (Zoom) defense itself. I wrote the code for all the animations, which were rendered in a program called Tecplot 360.
Here's the defense, if you want to hear actual explanations rather than just pretty slides
https://youtu.be/AV2a3V2A-Hk
Here's a 2-minute introduction to the topological structure of the electron charge density in ethylene.
https://youtu.be/5tgcJ0JpDzo
Then here's a way to decompose the electron charge density into an conceptually infinite number of regions with "well-defined" energies (which isn't true for an arbitrary region)
https://youtu.be/HKlEc6mD6uQ
Lastly, here's what that process looks like with ethyl alcohol, and how the result can be used to identify the unique chemical bonding regions
https://youtu.be/TfXNVdlE2NE
MikeinPA said:
Yeah. Made my day considerably less interesting though! I'm surprised this is even possible, but they didn't reconnect the in-vehicle HVAC temperature sensor, and also plugged in some wiring harnesses "backwards" or something, resulting in the A/C button inverting (light on means off), and the result was that I couldn't achieve consistent power consumption from the heater/AC in order to perform the cell voltage test in the repair manual.
If it comes to me being pushy, I'll certainly point to the clear lack of attention to detail these top-dollar techs provide.
There are a few DTCs which call for replacement of the Li-ion battery as the solution at the end of the diagnostic steps.
P3030 with P30F3, LBC Communication Failure and Total High-voltage sensor fail (2012 only*)
P30FC, temperature sensor reading high with Over current condition. >131°F
P33D4, Gradual Capacity Loss(2012), Battery Deterioration (2013)
P33E2, Over temperature of pack, >131°F
P33E6, excessive min-max cell voltage deviation, Step 7, if condensation is found inside pack.
*2013 removed the Total Voltage Sensor DTCs.
Another condition for module replacement (besides the < 5V condition) is found in P33E6 Step 9 when the difference between the two Cells in the same module exceeds 40mV.
Typical BMS conventions: 1 pouch is a cell; 2 pouches in parallel is a Cell; 2 Cells in series in the same metal box is a module.
P3030 with P30F3, LBC Communication Failure and Total High-voltage sensor fail (2012 only*)
P30FC, temperature sensor reading high with Over current condition. >131°F
P33D4, Gradual Capacity Loss(2012), Battery Deterioration (2013)
P33E2, Over temperature of pack, >131°F
P33E6, excessive min-max cell voltage deviation, Step 7, if condensation is found inside pack.
*2013 removed the Total Voltage Sensor DTCs.
Another condition for module replacement (besides the < 5V condition) is found in P33E6 Step 9 when the difference between the two Cells in the same module exceeds 40mV.
Typical BMS conventions: 1 pouch is a cell; 2 pouches in parallel is a Cell; 2 Cells in series in the same metal box is a module.
DaveinOlyWA
Well-known member
SageBrush said:
24 kwh pack started with 48 modules but that was changed in 2013? 2014? to 24 modules and 8 cells.
The 2.5 volt cutoff is a bit hard to swallow. I will have to scour my logs but I am thinking the lowest I have ever seen has been like 2.8 or so?
EDIT
Turtle on my S40 @ 8 GID, voltage range (per pair) 2.981 to 3.067 v SOC 1.7% 2.5? Not happening.
DaveinOlyWA
Well-known member
SageBrush said:
Sadly, the same parameters for the 30 kwh degradation warranty has been carried over to a pack more than 100% larger. How is that equitable? Only Nissan would figure out a way when paying for more, you get less.
DaveinOlyWA
Well-known member
SageBrush said:
Not sure what cell config has to do with warranties so lets put it another way. The 30 kwh only has to lose 10 kwh to get a new battery that is 33% larger. I have to lose over 22 kwh and will probably only qualify for the same sized pack.
I feel that my degradation should be set to 25% (or 3 bars will do in a pinch I guess) or 150,000 miles. I will accept either
DougWantsALeaf
Well-known member
Guessing at 100k miles you still be above 80% SoH.
DaveinOlyWA
Well-known member
DougWantsALeaf said:
yeah...no new pack for me
The Tesla Model S Plaid+ is presumed to have ~ a 135 kWh pack. By your reckoning they should get a new pack when 7.4% of new capacity is lost and the car range is down to a measly 481 miles.DaveinOlyWA said:
I'm trying and failing to come up with a polite descriptor for your 'reasoning'
DaveinOlyWA
Well-known member
SageBrush said:
You might if you put down the koolaide. What is Tesla's degradation warranty anyway?
Hi SageBrush,
Sorry for quoting your message with a clear start but as the original poster went silent after the beginning of this message thread, I thought it would be the best option to make it this way.
The original post really closely reminds me of my case with my Nissan Leaf 2019 (40 kWh) and I'm a bit desperate with this as the problem got worse since last winter. And this actually is the reason why I registered to this forum which really should be mentioned in all Nissan Leafs's manuals. :idea:
To all members who may be viewing my post and who might have had same problem as I'm having or who might know something about this kind of problem, I would be extremely thankful for any tips or ideas which may push me to right direction.
Last winter the car's battery level (SoC) started moving according to my "gas pedal's" movements in really cold temperatures. And with cold temperatures I mean -14 Celsius degrees / 6 degrees Fahrenheit - or colder. If I drove highway in a constant speed and with small power consumption, the SoC didn't change abnormally. But, if I hit the pedal to the metal, the SoC started to decrease rapidly: approx. 1%-point (p.p.) / 1 second and this went on for 10 %-points. When I lifted my foot from the pedal, the power regeneration kicked in and the the SoC started increase at the same rate it was earlier decreasing - all the way to the starting point.
As my car was under warranty, the local Nissan dealership arranged a battery-regulator (most likely worst translation ever, I don't know the right word and Google isn't helping :mrgreen to be changed to my battery pack. It was a small metal box which is inside the battery pack and needed a bigger work from the service guys as the battery pack needed, obviously, to be removed. After it was done, I was hoping that the problem was history but unfortunately I was wrong.
This winter, when the cold temperatures found their way to Finland again, the problem popped up again and even worse this time. Last winter the problem didn't involve any error messages but this time there were two different ones and Nissan suddenly goes to "turtle mode" which was really nice to experience in highway speeds: luckily there wasn't a car nearby to my back bumper. :evil:
Luckily we were able to make a video clip of this behavior which happens:
- Only when outside temperature is 6 degrees Fahrenheit and
- only when SoC hits 30 % (I'm pretty sure it always was that particular percentage).
And the clip itself:https://youtu.be/ivdJUyq18ZY
There's a more specific explanation in the video's description, in case someone sees this message and even has some free time to check the video out also.
The local Nissan dealership has been really nice and helpful but since there hasn't been too many Nissan Leaf problems here in Finland, they still don't have a complete "guidance book" to go through all cases which would need experience of same kind of problems in the past. As they inspected my car they said that the both batteries (the main battery pack and the 12V battery) were OK and the manufacturer's opinion is that there is a problem with the dashboard but they are still investigating that at the Nissan's end and they can't provide a fix to this yet. But when I saw this message thread, I feel like that they are something wrong with the battery pack after all.
Long story short: if the original poster sees this and eventually found out (and hopefully got his car fixed!) what was wrong with the car, all the information would be read carefully and really gratefully next to this monitor.
Sorry for my somewhat bad English and greetings from Finland!
Sorry for quoting your message with a clear start but as the original poster went silent after the beginning of this message thread, I thought it would be the best option to make it this way.
The original post really closely reminds me of my case with my Nissan Leaf 2019 (40 kWh) and I'm a bit desperate with this as the problem got worse since last winter. And this actually is the reason why I registered to this forum which really should be mentioned in all Nissan Leafs's manuals. :idea:
To all members who may be viewing my post and who might have had same problem as I'm having or who might know something about this kind of problem, I would be extremely thankful for any tips or ideas which may push me to right direction.
Last winter the car's battery level (SoC) started moving according to my "gas pedal's" movements in really cold temperatures. And with cold temperatures I mean -14 Celsius degrees / 6 degrees Fahrenheit - or colder. If I drove highway in a constant speed and with small power consumption, the SoC didn't change abnormally. But, if I hit the pedal to the metal, the SoC started to decrease rapidly: approx. 1%-point (p.p.) / 1 second and this went on for 10 %-points. When I lifted my foot from the pedal, the power regeneration kicked in and the the SoC started increase at the same rate it was earlier decreasing - all the way to the starting point.
As my car was under warranty, the local Nissan dealership arranged a battery-regulator (most likely worst translation ever, I don't know the right word and Google isn't helping :mrgreen
to be changed to my battery pack. It was a small metal box which is inside the battery pack and needed a bigger work from the service guys as the battery pack needed, obviously, to be removed. After it was done, I was hoping that the problem was history but unfortunately I was wrong.This winter, when the cold temperatures found their way to Finland again, the problem popped up again and even worse this time. Last winter the problem didn't involve any error messages but this time there were two different ones and Nissan suddenly goes to "turtle mode" which was really nice to experience in highway speeds: luckily there wasn't a car nearby to my back bumper. :evil:
Luckily we were able to make a video clip of this behavior which happens:
- Only when outside temperature is 6 degrees Fahrenheit and
- only when SoC hits 30 % (I'm pretty sure it always was that particular percentage).
And the clip itself:https://youtu.be/ivdJUyq18ZY
There's a more specific explanation in the video's description, in case someone sees this message and even has some free time to check the video out also.
The local Nissan dealership has been really nice and helpful but since there hasn't been too many Nissan Leaf problems here in Finland, they still don't have a complete "guidance book" to go through all cases which would need experience of same kind of problems in the past. As they inspected my car they said that the both batteries (the main battery pack and the 12V battery) were OK and the manufacturer's opinion is that there is a problem with the dashboard but they are still investigating that at the Nissan's end and they can't provide a fix to this yet. But when I saw this message thread, I feel like that they are something wrong with the battery pack after all.
Long story short: if the original poster sees this and eventually found out (and hopefully got his car fixed!) what was wrong with the car, all the information would be read carefully and really gratefully next to this monitor.
Sorry for my somewhat bad English and greetings from Finland!
Your English is better than many native English speakers can manage.
I didn't watch the video yet, but the description sounds like one or more cells in the battery are bad, or at least weak. The Battery Management System (BMS), which I think is what the dealer replaced, uses cell voltages to make decisions on how to display State of Charge (SOC), and when to slow or stop the car because of low charge. If some - or even one! - cells are weak, then they basically fool the BMS into 'thinking' that the car has less charge than it really has. To put it another way: the battery is only as strong as it weakest cells.
I didn't watch the video yet, but the description sounds like one or more cells in the battery are bad, or at least weak. The Battery Management System (BMS), which I think is what the dealer replaced, uses cell voltages to make decisions on how to display State of Charge (SOC), and when to slow or stop the car because of low charge. If some - or even one! - cells are weak, then they basically fool the BMS into 'thinking' that the car has less charge than it really has. To put it another way: the battery is only as strong as it weakest cells.
LeftieBiker said:Your English is better than many native English speakers can manage.
I didn't watch the video yet, but the description sounds like one or more cells in the battery are bad, or at least weak. The Battery Management System (BMS), which I think is what the dealer replaced, uses cell voltages to make decisions on how to display State of Charge (SOC), and when to slow or stop the car because of low charge. If some - or even one! - cells are weak, then they basically fool the BMS into 'thinking' that the car has less charge than it really has. To put it another way: the battery is only as strong as it weakest cells.
Yep.
Unfortunately, it can be a real chore to get dealerships to understand and acknowledge weak cells. And Nissan in the past has told customers to pound sand until DTC's are logged that are related to the weak cell. So I think the right approach is to do two things:
1. Take a dealership rep on a test drive with SoC below 30% and demonstrate turtle mode with acceleration
2. Keep pushing the SoC down with the same driving behavior until DTCs are logged
I agree with what LeftieBiker and SageBrush said and will add that internal cell resistance increases at lower temperatures so that is why you see this in cold weather. If you keep driving once it goes into Turtle mode (reduced power mode) until the car stops, it may set some error codes (I would only attempt this with a dealer representative riding along so they can see it for themselves and arrange for towing to their shop after it stops).
Hi,
Thank you all three for your quick replies on this matter! *waves at your general direction*
This really eases my mind that the battery pack would have the source of problem after all but yet the worst struggle is still ahead: how to get Nissan dealership to see this point of view. :?: I sent them the same video which can be seen in the Youtube link I linked in my first post so they should know how the problem affects the car and what can be seen on the dashboard while it happens.
I have no knowledge on LeafSpy but if I have understood correctly, it could be able to pinpoint the weaker cell(s) while driving or recharging the car?
I sent this message thread's link to the local Nissan dealership, hopefully it clarifies the situation at that end as well in case my previous explanations to them have been a bit confusing.
Thank you all three for your quick replies on this matter! *waves at your general direction*
This really eases my mind that the battery pack would have the source of problem after all but yet the worst struggle is still ahead: how to get Nissan dealership to see this point of view. :?: I sent them the same video which can be seen in the Youtube link I linked in my first post so they should know how the problem affects the car and what can be seen on the dashboard while it happens.
I have no knowledge on LeafSpy but if I have understood correctly, it could be able to pinpoint the weaker cell(s) while driving or recharging the car?
I sent this message thread's link to the local Nissan dealership, hopefully it clarifies the situation at that end as well in case my previous explanations to them have been a bit confusing.
