Sudden extreme battery charge loss while driving

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People with a battery problem can get some reference from my video below. You can try the following:

1. Try to get Nissan to repair or replace the battery under warranty. That usually doesn't go well.
2. You have a low mileage so replacing damaged modules is maybe still viable.
3. Try finding a good salvage battery. It is hard to get because it is a desirable product and it is VERY risky.
4. Find someone who can replace all the modules for you.
I use 117Ah CATL modules, they work much better then the original ones. But this is a tough task only for a person with appropriate knowledge, skills ant also tools.
Wish you all the best in 2025!

 
This is the "ultimate stress test" for an EV...and usually reveals weak/bad cells. 40 kWh packs seem to be more prone to bad "quality control", and I eventually replaced a weak cell/module in mine.
My 1st winter...Yesterday, I Drove my 2018 uphill with a 87% SOH battery at 53% SOCharge. Temp was -15C, the coldest so far. At 90km/h the battery Indicator suddenly dropped and low battery warning popped Up Along with Turtle mode light (for the first Time). I slowed down a little and once at the top of Hill, charge Indicator progressively went back Up to 50% charge! I suspect cold weather to be a major Factor, but also a weak cell about to fail. At 113,000km, is It normal or should I check for warranty claim?
 
Temp was -15C, the coldest so far. At 90km/h the battery Indicator suddenly dropped and low battery warning popped Up Along with Turtle mode light (for the first Time). I slowed down a little and once at the top of Hill, charge Indicator progressively went back Up to 50% charge! I suspect cold weather to be a major Factor, but also a weak cell about to fail. At 113,000km, is It normal or should I check for warranty claim?
I can pretty much guarantee that you will never quality for a warranty claim...because they will never reproduce those extreme conditions (both temperature and speed) for a sustained period. It's not ideal, but as long as your SOC returns to "normal"--and most importantly stays that way in "normal" conditions--all you have done is verify that there is a limit to what your (degraded) pack will deliver.
Don't shoot the messenger...and recognize that EVs have limitations (due to battery chemistry) in harsh environments.
 
Running an EV in the extreme cold is roughly analogous to running an older diesel car (from the 70's) in the cold. They have their limits.
Diesels today return far more fuel to the tank, so fuel system stays warmer than the old days. Fuel suppliers are better about mixing in #1 fuel in the cold.
Not a lot you can do for EV's in the cold, batteries will loose capacity and it takes more energy for the same trip when everything is stiff from the cold.
Parking inside, preferably where there is some heat, and not leaving discharged before a trip will help.
In the end it just takes planning for the cold and acceptance of the limitations.
 
Hi, here in montreal where i live this is normal winter daytime temperature. I dont mind if the power is limited or the range is less than in summer, but having the battery % drop and turtle mode on is not normal. I have this issue and thye last time the traction battery was disconnected by the BMS on the highway. What is really happening and not normal is that the % battery left indocator is using the weakest cell voltage to estimate the % and in that case, there is one outliar cell that has a big delta with the other cells. This is a cell that is dying and a defect. Look at the leafspy diagram i got the last time this happened to me. I can reproduce this almost everyday the temperature is below 0 celsius the night before.
 

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never quality for a warranty claim
I'm sorry I have to disagree. I've had two successful claims in these conditions.

The next few days are going to be a bit warmer in Quebec. If you try a warranty claim, make sure the battery pack is as cold as it can be when the dealer checks it. The best way to achieve this is to bring the car to the dealer between 40 and 50% one day ahead and have it sleep outside at -10C or below. The next day they'll try to record the problem. If they can, bingo, new/remanufactured pack for you. Else, you'll have to pay for the diagnostic which is about 300$CAD. They may ask to try multiple times.

And I hope your dealer is as nice as mine.

Otherwise, lithium batteries do have their limits indeed. What is normal and what is not, what is covered by the warranty, what should be and what is not is a matter of opinion here and is best answered by a good dealer.
 
0C (32F) is not what I consider extreme cold. I consider -20F extreme, and anything below -10F I would expect to see some problems hill climbing at 55 MPH.
Just yesterday, I was going to town at 5F and never had a problem.
 
Hi, here in montreal where i live this is normal winter daytime temperature. I dont mind if the power is limited or the range is less than in summer, but having the battery % drop and turtle mode on is not normal. I have this issue and thye last time the traction battery was disconnected by the BMS on the highway. What is really happening and not normal is that the % battery left indocator is using the weakest cell voltage to estimate the % and in that case, there is one outliar cell that has a big delta with the other cells. This is a cell that is dying and a defect. Look at the leafspy diagram i got the last time this happened to me. I can reproduce this almost everyday the temperature is below 0 celsius the night before.
That delta V should be more than obvious to a dealership, even as warm as 0 it is huge!
 
That delta V should be more than obvious to a dealership, even as warm as 0 it is huge!
We did a test yesterday with the nissan tech and he detected a 600 mv delta without warning message in the car. They let the car outside last night and they were supposed to test it cold this morning. No news yet, hoping thet will get more error code. The last time, the car threw 6 modules undervoltage DTCs.
 
Hi, here in montreal where i live this is normal winter daytime temperature. I dont mind if the power is limited or the range is less than in summer, but having the battery % drop and turtle mode on is not normal. I have this issue and thye last time the traction battery was disconnected by the BMS on the highway. What is really happening and not normal is that the % battery left indocator is using the weakest cell voltage to estimate the % and in that case, there is one outliar cell that has a big delta with the other cells. This is a cell that is dying and a defect. Look at the leafspy diagram i got the last time this happened to me. I can reproduce this almost everyday the temperature is below 0 celsius the night before.
I'm living on North Shore of MTL, so your observations are quite similar to mine, in terms of winter conditions. The tough part Will be to have the dealer appointment in similar weather, so they can find the same symptoms. Fortunately, il looks that weather forcast for the appointment day is below minus 10C.
 
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I'm sorry I have to disagree. I've had two successful claims in these conditions.

The next few days are going to be a bit warmer in Quebec. If you try a warranty claim, make sure the battery pack is as cold as it can be when the dealer checks it. The best way to achieve this is to bring the car to the dealer between 40 and 50% one day ahead and have it sleep outside at -10C or below. The next day they'll try to record the problem. If they can, bingo, new/remanufactured pack for you. Else, you'll have to pay for the diagnostic which is about 300$CAD. They may ask to try multiple times.

And I hope your dealer is as nice as mine.

Otherwise, lithium batteries do have their limits indeed. What is normal and what is not, what is covered by the warranty, what should be and what is not is a matter of opinion here and is best answered by a good dealer.
I fully agree with you, I'm in the same situation as Mrklar and I will prepare to my appointment as you suggested.
 
Update: The local dealer was eventually able to reproduce the sudden range loss issue with my car, helped in part by the super frigid temperatures in my area this week. The technician found diagnostic code P31B8 after experiencing a range loss event. I'm just beginning to research that code myself, but here is the next steps recommended by the dealer service department:

1) Replace the Telematics Control Unit (TCU) and program it, then test drive the car to see if the range loss symptoms persist.
2) If sudden range loss events continue, replace the Vehicle Control Module (VCM).

The cost of 1 & 2 were quoted at about $3,000 US. I asked whether any additional battery health diagnostics were performed and was told that battery health issues were not indicated in the error codes; the scans performed were all that's needed.

I'm curious to hear what you all think of this result.
 
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EH, I think they are barking up the wrong tree. The recommendation is correct for the code, but the code doesn't match the symptom.
I could be wrong, but I think the comm errors are a result of the voltage suddenly dropping not the other way around.
The way to diagnose a sudden loss of power while driving is to look at what is happening when the malfunction happens, not after.
Am I understanding that while driving the range drops quickly and then rises again? There are 2 or 3 peoples problems on this thread, so exactly what are symptoms you are having?
Likely best to start a new thread with EXACTLY what your symptoms are and the codes found.
 
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Hi, here in montreal where i live this is normal winter daytime temperature. I dont mind if the power is limited or the range is less than in summer, but having the battery % drop and turtle mode on is not normal. I have this issue and thye last time the traction battery was disconnected by the BMS on the highway. What is really happening and not normal is that the % battery left indocator is using the weakest cell voltage to estimate the % and in that case, there is one outliar cell that has a big delta with the other cells. This is a cell that is dying and a defect. Look at the leafspy diagram i got the last time this happened to me. I can reproduce this almost everyday the temperature is below 0 celsius the night before.
I live on North shore of Montreal. My Leaf as similar health % and internal resistance readings. Looking at your Leafspy screen capture, I got practically the same voltage drop (over 720mV) on mine with a very weak cell and two others that were quite low too. Typically, it produces a momentary drop in battery charge indicator from 55 to zero+ low charge warning + turtle mode that recovers pontanously once I finished climbing a 10% hill for 2 minutes or so, on my way home. Ambient temperature was -6 to-10c. In my case, this only occurs when charge level is below 60% and driving uphill at 90km/h.

I got to the Nissan dealer who was able to reproduce the symptoms from 55% charge at -6C. I was confirmed there was a problem within an hour. The dealer did not charge for the testing and told me they were sending the data to "Nissan engineering" to decide if they should "repair or replace the battery" on my 2018 Leaf that only has 113,000km. The verdict is expected within 2-3 weeks. Sounds like such symptoms are enough for a warranty claim. I let you know once I get their decisions and what kind of delay it will take to correct the problem. In the meantime, despite reduced range, I avoid such sudden power drop event by charging at 90 or 100% at home rather the usual 80%, because I intend to keep my Leaf for the longest time possible.
 
Just some observations:
I have a 2015 24Kwh Leaf so am long out of warranty, but have observed similar loss of power/turtle twice while having a fairly high load on the pack.
Once happened at -15F and the other around 3 degF. The first time I was just taking my Leaf out for the 1st time in cold like that to so how it handled it.
The more recent time it came as sort of a surprise, but I hadn't charged or used the car in over 36 hrs so sat with almost a full charge through temps much colder. I think the battery pack cooled to around -14 or so and the weather only started to warm.
Unfortunately I did not have Leafspy active on either trip.
I think what is happening is the load on the cells exceeds what they can provide at the temperature they happen to be at. Because the pack has a fair bit of thermal mass, it takes a long time for them to cool or heat.
In my case that meant that even with the air temp starting to moderate, then core temp of some cells were still cold enough to cause a problem.
Normally they are charged during the night, and I think this prevents the core of the pack from cooling enough for the problem to show most days.
I think the critical factors are the load, 10% grade is far above what I was driving on, and the core battery temp. These two factors come together to cause the problem to show at higher temps for some then others.
I may be wrong, but I don't think this kind of "problem" sets a DTC, rather when the load is removed the "problem" is considered resolved and no record of the problem remains in the DTC memory.
This leads to a big problem when the car is taken to the dealer, and no or unrelated DTC are in memory. At far too many dealerships, the rule is "no code= no problem" and no further time is spent trying to resolve a "non existent" problem!
It is very hard to see how a telemetrics comm problem could cause a loss of power!
The problem is the dealership personnel not putting the effort into reproducing the problem.
In this case it would involve operating the car under the same conditions that cause the problem, namely a "cold soak" of the battery, then driven briskly up the 10% grade.
Needless to say there are many monetary incentives to "sweep the problem under the rug" and deny there is a problem.
It has been close to 5 decades since I worked at a dealership, but I doubt how mechanics are paid has changed much. Diagnostic time is not paid for, it is supposed to be included in the rate for making a repair, but never covers putting in the time to diagnose complex or difficult problems, so you end up with "we couldn't reproduce the problem (with the car sitting still in the mechanic's bay) and there are no trouble codes, therefore there is no problem!
50 years or so you could petition the Mfg "district rep" to mediate the problem. They are salaried employees of the Mfg and if good, can spend the time with you to reproduce the problem.
This, however can be problematic as well as you need the weather to co-operate on the day and time the district rep is available.
In my case both events happened with the heater running on full and going up a modest hill around 55 mph, in short maximum load on the battery, that I would put on it for my usage.
 
Just some observations:
I have a 2015 24Kwh Leaf so am long out of warranty, but have observed similar loss of power/turtle twice while having a fairly high load on the pack.
Once happened at -15F and the other around 3 degF. The first time I was just taking my Leaf out for the 1st time in cold like that to so how it handled it.
The more recent time it came as sort of a surprise, but I hadn't charged or used the car in over 36 hrs so sat with almost a full charge through temps much colder. I think the battery pack cooled to around -14 or so and the weather only started to warm.
Unfortunately I did not have Leafspy active on either trip.
I think what is happening is the load on the cells exceeds what they can provide at the temperature they happen to be at. Because the pack has a fair bit of thermal mass, it takes a long time for them to cool or heat.
In my case that meant that even with the air temp starting to moderate, then core temp of some cells were still cold enough to cause a problem.
Normally they are charged during the night, and I think this prevents the core of the pack from cooling enough for the problem to show most days.
I think the critical factors are the load, 10% grade is far above what I was driving on, and the core battery temp. These two factors come together to cause the problem to show at higher temps for some then others.
I may be wrong, but I don't think this kind of "problem" sets a DTC, rather when the load is removed the "problem" is considered resolved and no record of the problem remains in the DTC memory.
This leads to a big problem when the car is taken to the dealer, and no or unrelated DTC are in memory. At far too many dealerships, the rule is "no code= no problem" and no further time is spent trying to resolve a "non existent" problem!
It is very hard to see how a telemetrics comm problem could cause a loss of power!
The problem is the dealership personnel not putting the effort into reproducing the problem.
In this case it would involve operating the car under the same conditions that cause the problem, namely a "cold soak" of the battery, then driven briskly up the 10% grade.
Needless to say there are many monetary incentives to "sweep the problem under the rug" and deny there is a problem.
It has been close to 5 decades since I worked at a dealership, but I doubt how mechanics are paid has changed much. Diagnostic time is not paid for, it is supposed to be included in the rate for making a repair, but never covers putting in the time to diagnose complex or difficult problems, so you end up with "we couldn't reproduce the problem (with the car sitting still in the mechanic's bay) and there are no trouble codes, therefore there is no problem!
50 years or so you could petition the Mfg "district rep" to mediate the problem. They are salaried employees of the Mfg and if good, can spend the time with you to reproduce the problem.
This, however can be problematic as well as you need the weather to co-operate on the day and time the district rep is available.
In my case both events happened with the heater running on full and going up a modest hill around 55 mph, in short order maximum load on the battery, that I would put on it for my usage
24Kwh battery is already quite limited, especially after a few years, degradation builds up. To get decent mileage, especially when weather is cold, you must charge close to 100% which will speed up battery degradation even more. If it still is enough for your needs, fine, but in any case, checking for a battery fix or battery swap shop in your area would be a wise precaution. It is likely to fail completely rather quickly IMHO.
 
Na, my battery hasn't degraded hardly at all in the year I bought it. Not by a long shot.
It was caused by the extreme cold.
the 100% "rule" does not exist.
Best practice is to not charge to 100% AND LEAVE it there for many days.
I only see the problem twice since I purchased, and both times were when the car sat in -15f temps. It is not a reason to condemn the battery. It still made the trip to town and back without trouble.
When it will no longer do what I bought it for, then and only then will I address the problem.
 
I had a similar situation about a week ago with my 2018 Nissan Leaf. I was driving to work early in the morning and during a long climb uphill, the battery charge suddenly dropped from 45% to 10% and I had to slowly pull off the road. After 1-2 minutes the battery charge level returned, but the situation scared me a lot. I immediately took the car to the dealer and explained the situation. Yesterday the dealer called me and said that the manufacturer officially acknowledged the battery problem and agreed to replace it under warranty. But it may take up to two months, although the dealer promised to provide a loaner car for the duration of the repair.
 
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