2016-2017 model year 30 kWh bar losers and capacity losses

[ironmanco]

Do you have any idea of battery temperatures after your QCs ?

No, I don't. I just recently got leafspy up and running and haven't even set up logging yet. I can do a couple of test QCs and see but sitting at SOH-83% I'm not sure how much I want to test it.

 

[Oils4AsphaultOnly]

FWIW this three bar loser car in central Florida has only been fast charged once we know of; the day delivery was taken at the dealer. We don't know if it might have been fast charged other times before delivery. Hard to see how it could have been too significant.

So, what's the going theory on the biggest killer of the 30kWh packs? Would the fact that I do 50/50 L2/L3 charging be the cause of an 83% SOH after 34k miles? I can tell you that I adhere to all the other battery upkeep guidelines - rarely charge to 100%, never store @ 100% and I'm in a pretty temperate climate - if not on the cooler side.

I'm actually headed down to the Nissan battery plant in TN at the beginning of December, so I'm hoping to get a chance to talk with some of the folks there.

There seems to be 2 separate theories. DaveinOlyWA's theory is that any 30kwh leaf built before Feb '16 is defective and will degrade regardless of temp/environment/care. These folks WILL get a warranty replacement, because of how fast their capacity is degrading.

There's a second one that the 30kwh chemistry just plain sucks as compared to the 24kwh leaf's.

I think they're not mutually exclusive, because of my experience this past year. I'm not seeing the degradation rate that others with earlier builds (yourself included) are seeing. But my battery is degrading fast enough that I might qualify for a warranty replacement (something that wasn't possible with my 2013 (turned in after 3 years and 45k miles with ~79% degradation).

Nobody seems to have evidence that it's as durable or more durable than the 24kwh, but due to DaveinOlyWA's theory, it'll be another year before we can say one way or the other.

 

[ironmanco]

There seems to be 2 separate theories. DaveinOlyWA's theory is that any 30kwh leaf built before Feb '16 is defective and will degrade regardless of temp/environment/care. These folks WILL get a warranty replacement, because of how fast their capacity is degrading.

There's a second one that the 30kwh chemistry just plain sucks as compared to the 24kwh leaf's.

I think they're not mutually exclusive, because of my experience this past year. I'm not seeing the degradation rate that others with earlier builds (yourself included) are seeing. But my battery is degrading fast enough that I might qualify for a warranty replacement (something that wasn't possible with my 2013 (turned in after 3 years and 45k miles with ~79% degradation).

Nobody seems to have evidence that it's as durable or more durable than the 24kwh, but due to DaveinOlyWA's theory, it'll be another year before we can say one way or the other.

That's good info. I'm definitely going to have some talking points when I head down to TN in December. Is the battery replacement warranty trigger for the 30kWh battery that same as the 24kWh ones?

I haven't seen a comment stating whether I can recover any SOH by some regular L2 charging so I may just return back to my 50/50 profile of L2/L3 charging since I'm probably on track for a warranty replacement.

 

[ironmanco]

Never mind....I just found the answer to my question:


Lithium-ion Battery Gradual Capacity Loss:

IIn addition to the Lithium-ion Battery Coverage for defects in materials or workmanship (96 months/100,000 miles, whichever comes first), the Nissan LEAF® Lithium-ion battery is also warranted against capacity loss below nine bars of capacity as shown on the vehicle’s battery capacity level gauge for a period of 96 months or 100,000 miles (whichever occurs first) with the 30 kWh battery [*] . See your Owner's Manual for tips on maximizing battery life and capacity.

 

[LTLFTcomposite]

Do the "tips" for maximizing battery life and capacity include anything about buying an EV from anyone but Nissan?

 

[johnlocke]

Never mind....I just found the answer to my question:


Lithium-ion Battery Gradual Capacity Loss:

IIn addition to the Lithium-ion Battery Coverage for defects in materials or workmanship (96 months/100,000 miles, whichever comes first), the Nissan LEAF® Lithium-ion battery is also warranted against capacity loss below nine bars of capacity as shown on the vehicle’s battery capacity level gauge for a period of 96 months or 100,000 miles (whichever occurs first) with the 30 kWh battery [*] . See your Owner's Manual for tips on maximizing battery life and capacity.

No you didn't. You don't know what a"loss below nine bars" actually means. According to someone with access to the shop manuals you will drop the fourth bar at 63%. Several owners have reported it at around 60% and I believe that there's someone who reported 66%. We actually don't have enough data yet to nail it down. As more 2016's age enough to trigger a warranty replacement, we'll get a better idea.

As far as DCFC being a problem, it's only a 2-3C charge rate. Most Li-Ion batteries accept 4-6C charge rates without any problem. Battery heating during DCFC could be a problem as some people have reported a couple of bars temp increase during DCFC. Unfortunately, Nissan chose to implement overlapping ranges for the temp bars so you have no real idea what the temp actually is or how much each bar is worth. This needs to be checked with leaf Spy to get an accurate reading. Next time I do a fast charge I'll try to remember to write down the actual numbers.

 

[SageBrush]

Do you have any idea of battery temperatures after your QCs ?

No, I don't. I just recently got leafspy up and running and haven't even set up logging yet. I can do a couple of test QCs and see but sitting at SOH-83% I'm not sure how much I want to test it.

A glance at the temperature bars would be of some value. If the QC'ing ends up with say less than 8 bars then it is an unlikely suspect in explaining your rapid battery degradation.

You asked whether your behavior is the cause. You need some information to sort out the possibilities.

 

[SageBrush]

FWIW this three bar loser car in central Florida has only been fast charged once we know of; the day delivery was taken at the dealer. We don't know if it might have been fast charged other times before delivery. Hard to see how it could have been too significant.

So, what's the going theory on the biggest killer of the 30kWh packs? Would the fact that I do 50/50 L2/L3 charging be the cause of an 83% SOH after 34k miles? I can tell you that I adhere to all the other battery upkeep guidelines - rarely charge to 100%, never store @ 100% and I'm in a pretty temperate climate - if not on the cooler side.

I'm actually headed down to the Nissan battery plant in TN at the beginning of December, so I'm hoping to get a chance to talk with some of the folks there.

There seems to be 2 separate theories. DaveinOlyWA's theory is that any 30kwh leaf built before Feb '16 is defective and will degrade regardless of temp/environment/care. These folks WILL get a warranty replacement, because of how fast their capacity is degrading.

There's a second one that the 30kwh chemistry just plain sucks as compared to the 24kwh leaf's.

I think they're not mutually exclusive, because of my experience this past year. I'm not seeing the degradation rate that others with earlier builds (yourself included) are seeing. But my battery is degrading fast enough that I might qualify for a warranty replacement (something that wasn't possible with my 2013 (turned in after 3 years and 45k miles with ~79% degradation).

Nobody seems to have evidence that it's as durable or more durable than the 24kwh, but due to DaveinOlyWA's theory, it'll be another year before we can say one way or the other.

Dave's guess is arbitrary. Nothing preventing him from deciding that actually, the crap packs were put in cars through Feb 2018, and we need to wait until 2019 to know ... ...

All we know is that 30 kWh packs are not holding up as well as 24 kWh packs (and that is piss poor itself.) If and when things change, the new information will change our opinions of the whats and whys of 30 kWh packs.

 

[DaveinOlyWA]

FWIW this three bar loser car in central Florida has only been fast charged once we know of; the day delivery was taken at the dealer. We don't know if it might have been fast charged other times before delivery. Hard to see how it could have been too significant.

I pretty much confirmed that fast charging and the heat that results is a pretty small player in the Degradation World.

 

[DaveinOlyWA]

FWIW this three bar loser car in central Florida has only been fast charged once we know of; the day delivery was taken at the dealer. We don't know if it might have been fast charged other times before delivery. Hard to see how it could have been too significant.

So, what's the going theory on the biggest killer of the 30kWh packs? Would the fact that I do 50/50 L2/L3 charging be the cause of an 83% SOH after 34k miles? I can tell you that I adhere to all the other battery upkeep guidelines - rarely charge to 100%, never store @ 100% and I'm in a pretty temperate climate - if not on the cooler side.

I'm actually headed down to the Nissan battery plant in TN at the beginning of December, so I'm hoping to get a chance to talk with some of the folks there.

There seems to be 2 separate theories. DaveinOlyWA's theory is that any 30kwh leaf built before Feb '16 is defective and will degrade regardless of temp/environment/care. These folks WILL get a warranty replacement, because of how fast their capacity is degrading.

There's a second one that the 30kwh chemistry just plain sucks as compared to the 24kwh leaf's.

I think they're not mutually exclusive, because of my experience this past year. I'm not seeing the degradation rate that others with earlier builds (yourself included) are seeing. But my battery is degrading fast enough that I might qualify for a warranty replacement (something that wasn't possible with my 2013 (turned in after 3 years and 45k miles with ~79% degradation).

Nobody seems to have evidence that it's as durable or more durable than the 24kwh, but due to DaveinOlyWA's theory, it'll be another year before we can say one way or the other.

I think both is correct. The early packs are suffering degradation MUCH faster than the 2011 packs were in Phoenix.

On the 2nd theory; there is still much higher levels of degradation visible even in packs just a few months old and so we can posit the tech sucks, the BMS sucks or the SW sucks. I think its a combination of all three.

I ran a 7 month long experiment to try to test "something" and although results seem clear to me the reality is the only thing that is for certain is what didn't happen (degradation) in one of our longest and warmest Summers since I have lived here (30+ years)

But the fact remains is that we still have

People in cool climates seeing heavy degradation
People in hot climates that are doing MUCH better than their neighbors

And this is present in all packs made since Spring 2016.

This should bring up the an obvious conclusion that yeah the batteries are a problem but there are things we can do to mitigate the issues.

 

[SageBrush]

FWIW this three bar loser car in central Florida has only been fast charged once we know of; the day delivery was taken at the dealer. We don't know if it might have been fast charged other times before delivery. Hard to see how it could have been too significant.

I pretty much confirmed that fast charging and the heat that results is a pretty small player in the Degradation World.

In Olympia, WA, with your car and your drive habits.
Try to avoid extrapolating to other situations in the absence of supporting data.

 

[SageBrush]

So, what's the going theory on the biggest killer of the 30kWh packs? Would the fact that I do 50/50 L2/L3 charging be the cause of an 83% SOH after 34k miles? I can tell you that I adhere to all the other battery upkeep guidelines - rarely charge to 100%, never store @ 100% and I'm in a pretty temperate climate - if not on the cooler side.

I'm actually headed down to the Nissan battery plant in TN at the beginning of December, so I'm hoping to get a chance to talk with some of the folks there.

There seems to be 2 separate theories. DaveinOlyWA's theory is that any 30kwh leaf built before Feb '16 is defective and will degrade regardless of temp/environment/care. These folks WILL get a warranty replacement, because of how fast their capacity is degrading.

There's a second one that the 30kwh chemistry just plain sucks as compared to the 24kwh leaf's.

I think they're not mutually exclusive, because of my experience this past year. I'm not seeing the degradation rate that others with earlier builds (yourself included) are seeing. But my battery is degrading fast enough that I might qualify for a warranty replacement (something that wasn't possible with my 2013 (turned in after 3 years and 45k miles with ~79% degradation).

Nobody seems to have evidence that it's as durable or more durable than the 24kwh, but due to DaveinOlyWA's theory, it'll be another year before we can say one way or the other.

I think both is correct. The early packs are suffering degradation MUCH faster than the 2011 packs were in Phoenix.

On the 2nd theory; there is still much higher levels of degradation visible even in packs just a few months old and so we can posit the tech sucks, the BMS sucks or the SW sucks. I think its a combination of all three.

I ran a 7 month long experiment to try to test "something" and although results seem clear to me the reality is the only thing that is for certain is what didn't happen (degradation) in one of our longest and warmest Summers since I have lived here (30+ years)

But the fact remains is that we still have

People in cool climates seeing heavy degradation
People in hot climates that are doing MUCH better than their neighbors

And this is present in all packs made since Spring 2016.

This should bring up the an obvious conclusion that yeah the batteries are a problem but there are things we can do to mitigate the issues.

Or that manufacture QC is poor, leading to noise in our attempt to isolate risk factors

 

[DaveinOlyWA]

FWIW this three bar loser car in central Florida has only been fast charged once we know of; the day delivery was taken at the dealer. We don't know if it might have been fast charged other times before delivery. Hard to see how it could have been too significant.

I pretty much confirmed that fast charging and the heat that results is a pretty small player in the Degradation World.

In Olympia, WA, with your car and your drive habits.
Try to avoid extrapolating to other situations in the absence of supporting data.

This is the results others have seen as well. Cars that fast charge EXCESSIVELY and drive a lot suffer much lower levels of degradation. This is common thru several types of vehicles including ones with and without TMS.

So what is different? Its "time" at high temps AND high SOC. Cars that pile up miles essentially charge up and go. Time at high SOC (regardless of temp) is minimized. So the highest rate of degradation is minimized.

 

[Oils4AsphaultOnly]

I think both is correct. The early packs are suffering degradation MUCH faster than the 2011 packs were in Phoenix.

On the 2nd theory; there is still much higher levels of degradation visible even in packs just a few months old and so we can posit the tech sucks, the BMS sucks or the SW sucks. I think its a combination of all three.

I ran a 7 month long experiment to try to test "something" and although results seem clear to me the reality is the only thing that is for certain is what didn't happen (degradation) in one of our longest and warmest Summers since I have lived here (30+ years)

But the fact remains is that we still have

People in cool climates seeing heavy degradation
People in hot climates that are doing MUCH better than their neighbors

And this is present in all packs made since Spring 2016.

This should bring up the an obvious conclusion that yeah the batteries are a problem but there are things we can do to mitigate the issues.

Or that manufacture QC is poor, leading to noise in our attempt to isolate risk factors

I agree that blaming the BMS is a stretch, but claiming poor manufacturing QC from a plant that had good results with QC'ing their 24kwh batteries seems more of a stretch.

We [Edit: I] know a change of chemical composition (maybe silicon was added?) is responsible for the increased capacity, so blaming that same change for the unreliability of the battery is far more likely.

 

[DaveinOlyWA]

I think both is correct. The early packs are suffering degradation MUCH faster than the 2011 packs were in Phoenix.

On the 2nd theory; there is still much higher levels of degradation visible even in packs just a few months old and so we can posit the tech sucks, the BMS sucks or the SW sucks. I think its a combination of all three.

I ran a 7 month long experiment to try to test "something" and although results seem clear to me the reality is the only thing that is for certain is what didn't happen (degradation) in one of our longest and warmest Summers since I have lived here (30+ years)

But the fact remains is that we still have

People in cool climates seeing heavy degradation
People in hot climates that are doing MUCH better than their neighbors

And this is present in all packs made since Spring 2016.

This should bring up the an obvious conclusion that yeah the batteries are a problem but there are things we can do to mitigate the issues.

Or that manufacture QC is poor, leading to noise in our attempt to isolate risk factors

I agree that blaming the BMS is a stretch, but claiming poor manufacturing QC from a plant that had good results with QC'ing their 24kwh batteries seems more of a stretch.

We [Edit: I] know a change of chemical composition (maybe silicon was added?) is responsible for the increased capacity, so blaming that same change for the unreliability of the battery is far more likely.

well without data, its possible the BMS was wrong and adjusted. the original BMS simply had too much DoD and charged to a voltage that was a smidge too high.

 

[SageBrush]

I think both is correct. The early packs are suffering degradation MUCH faster than the 2011 packs were in Phoenix.

On the 2nd theory; there is still much higher levels of degradation visible even in packs just a few months old and so we can posit the tech sucks, the BMS sucks or the SW sucks. I think its a combination of all three.

I ran a 7 month long experiment to try to test "something" and although results seem clear to me the reality is the only thing that is for certain is what didn't happen (degradation) in one of our longest and warmest Summers since I have lived here (30+ years)

But the fact remains is that we still have

People in cool climates seeing heavy degradation
People in hot climates that are doing MUCH better than their neighbors

And this is present in all packs made since Spring 2016.

This should bring up the an obvious conclusion that yeah the batteries are a problem but there are things we can do to mitigate the issues.

Or that manufacture QC is poor, leading to noise in our attempt to isolate risk factors

I agree that blaming the BMS is a stretch, but claiming poor manufacturing QC from a plant that had good results with QC'ing their 24kwh batteries seems more of a stretch.

We [Edit: I] know a change of chemical composition (maybe silicon was added?) is responsible for the increased capacity, so blaming that same change for the unreliability of the battery is far more likely.

I'm not claiming anything; I'm pointing out a possibility that should be accounted for.
As for Nissan QC, I'm not so sure it was anything great to begin with, but it would not surprise me in the least to learn that it took a drop from the day Nissan decided to exit AESC.

 

[SageBrush]

We [Edit: I] know a change of chemical composition (maybe silicon was added?) is responsible for the increased capacity

Evidence ?
Did the car weight stay the same ?

Or ...
Is Nissan overcharging the battery ?!

 

[Oils4AsphaultOnly]

I agree that blaming the BMS is a stretch, but claiming poor manufacturing QC from a plant that had good results with QC'ing their 24kwh batteries seems more of a stretch.

We [Edit: I] know a change of chemical composition (maybe silicon was added?) is responsible for the increased capacity, so blaming that same change for the unreliability of the battery is far more likely.

well without data, its possible the BMS was wrong and adjusted. the original BMS simply had too much DoD and charged to a voltage that was a smidge too high.

You can't adjust the voltage down, _decrease_ the DoD, AND maintain the same battery capacity. Not without making another tweak of the chemistry anyway. So far, every other EV manufacturer has gotten increased battery capacity via a chemistry change.

 

[Oils4AsphaultOnly]

We [Edit: I] know a change of chemical composition (maybe silicon was added?) is responsible for the increased capacity

Evidence ?
Is Nissan overcharging the battery ?!

Not sure what overcharging has to do with changing the chemistry, but see my response to Dave about ruling out the BMS. Also look to Tesla's 90kwh battery pack (and the subsequent supercharger throttling) for my speculation on adding silicon.

 

[SageBrush]

Not sure what overcharging has to do with changing the chemistry,

Everything, at least as I understand battery chemistry.
I use 'overcharging' to mean a higher end voltage at "100%" charged

I do not remember exactly, but cells in a 24 kwh model are charged to "full" when they reach 4.125 volts or thereabouts. They can be charged to a higher voltage (up to the Nernst potential of the half cell) at the cost of accelerated degradation