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

DaveinOlyWA said:

It is not recovery you are seeing with improved numbers. Its better top end pack balancing

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What does this mean ?

I look at my pack in LeafSpy and see a maximum delta of 0 - 15 mv between modules. That is not enough to explain any significant Ahr differences.

On a related note, how are the Ahr and kWh rating calculated ?
There is some basic physics here I don't understand where the LEAF is concerned since I usually think of a battery capacity being determined during a controlled voltage charging cycle but that cannot be the method in a LEAF.

DaveinOlyWA wrote:
It is not recovery you are seeing with improved numbers. Its better top end pack balancing

What does this mean ?

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I think he might mean the Nissan algorithm that determines the SOH might favor cells that are very close in voltage, which happens during the balancing process. Balancing happens most significantly when the pack is topping off the charge when near full. Although the SOH reading might not be a super-accurate indicator of a battery's true health, it IS useful in relative comparisons between batteries that we all own, which is what this thread is about.

Speaking of which, here is another data point on my new 2017 SV:

Another 50 miles, another SOH % decline. I now have 320 miles on the car, SOH down to 94%, Hx 89%. Every 50 miles I'm losing a % SOH like clockwork. I've done a L2 6kW charge, let the cells balance and did some freeway driving and it didn't help. I can't believe the battery health is going to continue to decline at this rate because I'd lose my first capacity bar before I hit 1000 miles. But who knows? Every time I connect Leaf Spy I cringe.......then take a screen shot.

At this point my new car's battery stats have dropped below the used 2016 I was looking at. With 11,000 miles it was reporting higher GOM mileage, GIDs, SOH and Hx. Super lame.

SageBrush said:

DaveinOlyWA said:

It is not recovery you are seeing with improved numbers. Its better top end pack balancing

Click to expand...

What does this mean ?

I look at my pack in LeafSpy and see a maximum delta of 0 - 15 mv between modules. That is not enough to explain any significant Ahr differences.

On a related note, how are the Ahr and kWh rating calculated ?
There is some basic physics here I don't understand where the LEAF is concerned since I usually think of a battery capacity being determined during a controlled voltage charging cycle but that cannot be the method in a LEAF.

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First off we need to understand that the #1 parameter is poor Nissan instrumentation that gives us these wild fluctuations.

The other thing we need to understand is EVERYTHING we do is a trade off. There is no action that does not have consequences.

The other thing is that there is HUGE disparity from one car to another INCLUDING one in similar areas. It is this we need to understand. So the conjecture of this and that mattering or not mattering is only that. Because no matter what one person says is the cause of their degradation, we have another who is doing the same thing and they are fine.

So what is the key differences here? Is it weather, Driving style, time on the lot, charging patterns? Or is it simply the newer the pack, the better?

I am betting its a combination of all of that. I have a leased 2016 S 30 build date 10/16 picked up 11/11/16. Time on lot probably as close to zero as you can get. Right now I am in the process of experimenting with the car centering on "heat abuse" I hope to be able to see some results within the next 2 months (which means signs of degradation) that likely won't clear up a lot but will be another step towards having more insight.

as far as how important is top end pack balancing? Its vital, its ALL vital. Why would Nissan go thru the motions of creating the SW that takes up to an hour to run at the end of every charging cycle if it meant nothing?

DaveinOlyWA said:

...First off we need to understand that the #1 parameter is poor Nissan instrumentation that gives us these wild fluctuations...

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Neither Nissan or any other responsible BEV manufacturer has claimed that the on-board instrumentation can accurately gauge either remaining available energy capacity, or total battery capacity losses over time.

Nissan's solution to this limitation was to provide the highly inaccurate LBC (BMS) data to the driver only using the two twelve-bar displays, without ever attempting to specify any specific energy values per bar.

You really can't blame Nissan for the foolishness of those who choose to access their LBCs and try to use that data for purposes it is so obviously incapable of accurately providing.

Until a few decades ago (when gas gauges were dampened, achieving an effect similar to what Nissan did with the LEAF's 12 bar displays) fuel gauges in ICEVs changed every time you accelerated or decelerated or took a turn, as the float measuring the gasoline level bobbed up and down.

I can't recall any driver believing the actual amount of gasoline remaining was increasing or decreasing when this occurred, but If they had, I don't think you would have held the ICEV manufacturer responsible for "poor instrumentation"...

Inaccurate as the battery status readings may be, there are two real-world implications of the imperfect Nissan software:

1. Declining resale value of the car as capacity bars go away.
2. If the car 'thinks' its battery is in poor shape or low charge then it will limit your driving range.

Maybe having access to the internal battery readings is a little TMI, but even though we look at SOH, Hx and the like with one eye closed there are valid reasons to be concerned, and try to understand them better because they really do affect us. Trading experiences is helping us all learn how to use this car better, and giving us a few things to look out for as well.

rmorgansd said:

Inaccurate as the battery status readings may be, there are two real-world implications of the imperfect Nissan software:

1. Declining resale value of the car as capacity bars go away.
2. If the car 'thinks' its battery is in poor shape or low charge then it will limit your driving range...

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1. The average retail value of a ~six year old "24 kWh" LEAF showing 12 capacity bars seems to only be ~$2k higher than one with eight bars, from what I can tell.

2. That does not seem to be the case for early "24 kWh" packs.

I and other 2011-12 LEAF owners experienced an apparent miraculous healing of their packs after a Nissan provided an LBC software update:

Had the P3227 reprogram done today: interesting results.

http://www.mynissanleaf.com/viewtopic.php?f=27&t=13273

I can personally report my observations of no real increase in available capacity or range, just a temporary increase in gids, and corresponding decrease in wh/gid, which remained highly variable.

That update did not in any way effect the more useful kWh use reports from CW/NC reflected in the dash and nav screen m/kWh displays, BTW.

rmorgansd said:

From my experience with Li-Ion they don't tend to self-recover a lot. A little here and there but you can't regain capacity similar to when you cycle an old Ni-Cad or Ni-MH. In fact, one of the worst things you can do to Li-Ion is deep discharge then charge to full. You'll get the longest life by keeping it between about 40 to 80%, although we all recognize that doesn't work well in an EV where you want to go on a long trip.

Very interesting report from Battery University on the Nissan Leaf battery where they were studying early capacity loss. They disassembled some batteries and found the problem. They found what I surmised an an earlier post.....that sitting around at full charge prematurely ages the battery. A quote from the report:

An interesting discovery was made by NASA in that Li-ion dwelling above 4.10V/cell tend to decompose due to electrolyte oxidation on the cathode

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Entire report can be found here: http://batteryuniversity.com/learn/article/bu_808b_what_causes_li_ion_to_die

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I found that my 2016 had drifted as low as 92% SOH when I was only driving it 5 - 8 miles per day to the train station and just by taking a couple of long drives (80 miles round trip on a single charge) then recharging fully, my SOH has climbed back up to 95%. So I don't know if that's just instrumentation, or if I've just balanced the pack better by giving it a good long pull on the battery. I drove it once to Bellevue from Tacoma and once to Olympia (up a long steep hill on the way back) and returned home with about 20% each trip, and my SOH climbed after each drive. Odd, but encouraging perhaps? Sounds like I need to go do something fair to midland far away a couple times a month on a Saturday.

Maybe it's more to do with their algorithm than the true state of the battery, not sure. Over the last week I've put another 100 miles on my new 2017 SV , the car now has 399 miles on it and the SOH has gone down another notch to 93%. Hx is now 87%. We had a heat spell, and now it's cold and raining. Some freeway driving, some in-town driving. A few L2 charges and more L1 and so far my readings have only declined. It is losing reported capacity faster than I ever imagined it would. I have seen 3 yr old cars with 20,000 miles with better reported battery health. Takes some of the fun out of it.

I'd like to see the battery health readings pop back up like some have reported. I'll let you know what happens as I check back here every so often.

rmorgansd: Thanks for the update.

Can you update your location info via your user name in the upper right > User Control Panel > Profile tab? That way, we don't need to ask in future posts/threads or do sleuthing to deduce it.

rmorgansd said:

Maybe it's more to do with their algorithm than the true state of the battery, not sure. Over the last week I've put another 100 miles on my new 2017 SV , the car now has 399 miles on it and the SOH has gone down another notch to 93%. Hx is now 87%.

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I think what you're experiencing is what I did in December / January. My 2016 SL car came off the lot @ 98% SOH, promptly plunged to 92% over the first 1000 miles and now has rebounded to 96% SOH and I haven't quite hit 3k yet. I can't tell how much of this behavior is real performance change or just a combination of all the slop in all the variables.

I think that you folks should stop worrying about SOH - on a BRAND NEW 2016, worrying about your capacity is premature, and in fact silly... At 300, or even 1000 miles, the car has not even begun to acclimate itself... The battery needs ALOT of charges AND deep discharges (30-40%) in a short amount of time for the battery to come to true working capacity... If you only drive 3-5 miles daily, you have not even begun to use the capacity of the car and the battery.

If you only drive short distances and charge the battery every 5-10 days, then the battery is suffering from lack of use, similar to muscle tone deterioration when you do not exercise. If you are a short distance driver, just drive the car, and don't obsess about your Leafspy... I think we have too many ways to measure things today, and we love to obsess on things - like how our children are developing, or all the specs of all of our crap we buy..

PS - Just to give you an idea, I have a 2015 since new, with 35K miles on it. I drive the pants off of that car, and the SOH is still at 99.5%.... This weekend, I drove it on a 250 mile trip in one day, with many charges, and today, my GOM (at 100%) is 130 miles, better than when it was new....

I purchased a 2016 SL in December of 2015. The first year I drove 75 miles round trip commute and charged 5 days a week. Since January this year commute is down to 22 miles round trip charging every couple of days. I have just lost my 3rd battery bar just under 27,000 miles. I have only quick charged 3 times. I don't leave it sitting charged. I really expected the battery to last longer. The battery really can't take the Phoenix, Az heat.

bakermel1 said:

I purchased a 2016 SL in December of 2015. The first year I drove 75 miles round trip commute and charged 5 days a week. Since January this year commute is down to 22 miles round trip charging every couple of days. I have just lost my 3rd battery bar just under 27,000 miles. I have only quick charged 3 times. I don't leave it sitting charged. I really expected the battery to last longer. The battery really can't take the Phoenix, Az heat.

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No offense to you, brother, but shouldn't people in HOT areas like AZ, STOP BUYING LEAFS? We know that those areas are not good for EVs, and people insist in continuing to buy these cars?? I think it's like continuing to try growing crops in Death Valley, or buying convertibles in Siberia???.... We know it will fail???

powersurge said:

No offense to you, brother, but shouldn't people in HOT areas like AZ, STOP BUYING LEAFS? We know that those areas are not good for EVs, and people insist in continuing to buy these cars??

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There's nothing wrong with buying an EV in a hot area, provided it's anything but a Nissan! There are plenty of happy Volt and Tesla owners in Phoenix...

i cannot help wondering why Nissan does not have "battery cooler" package for hot weather regions. They have "battery heater" package for cold weather regions.

powersurge said:

bakermel1 said:

I purchased a 2016 SL in December of 2015. The first year I drove 75 miles round trip commute and charged 5 days a week. Since January this year commute is down to 22 miles round trip charging every couple of days. I have just lost my 3rd battery bar just under 27,000 miles. I have only quick charged 3 times. I don't leave it sitting charged. I really expected the battery to last longer. The battery really can't take the Phoenix, Az heat.

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No offense to you, brother, but shouldn't people in HOT areas like AZ, STOP BUYING LEAFS? We know that those areas are not good for EVs, and people insist in continuing to buy these cars?? I think it's like continuing to try growing crops in Death Valley, or buying convertibles in Siberia???.... We know it will fail???

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Nissan should stop selling Leafs in the Southwest or at least fess up to the truth that the battery has problems in hot climates. When I bought my Leaf, Nissan conveniently forgot to mention that. Nissan told me that the battery had a 8 year warranty and typically would have 80% of its capacity left at 100,000 miles. The car is now 1 1/2 years old and has 28,000 miles on it. It is down to 81% capacity and the 12th bar comes and goes. If the first bar is twice the value of the other bars then I could be looking at 50% capacity before the warranty kicks in. Talk about deceptive advertising. If I lose 4 bars out of 12, I would expect to have 2/3 of the capacity left not 1/2. I can use the car for my needs with 2/3 of the capacity but not with 1/2.

rmorgansd: Thanks for the update.

Can you update your location info via your user name in the upper right > User Control Panel > Profile tab? That way, we don't need to ask in future posts/threads or do sleuthing to deduce it.

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Done. Thank you.
Robert

I'm fascinated by everyone's differing experiences with their 2016 leaf! Aside from an issue with the charge timer starting the charge at the wrong time (it finishes ~3hrs before it's supposed to), I am still seeing 100% SOH (it dropped to 99% last month, but a full balance charge restored it 100%).

I charge mine every 2 out of 3 days and usually only to 90% (set the timer to 11am and manually unplug it at 7:30am). I've noticed that it reaches 100% charge about 30 minutes before it finishes the balancing charge. I have a parking garage at work too, so my leaf never parks out in the sun for more than a couple of times a month.

My 2013 leaf was down to 80% SOH after 48k miles. Am interested to see how this all holds after 30k miles.

powersurge said:

I think that you folks should stop worrying about SOH - on a BRAND NEW 2016, worrying about your capacity is premature, and in fact silly... At 300, or even 1000 miles, the car has not even begun to acclimate itself...

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You sir, are right outside your mind. This thing we do is precisely WHAT men do. I've been fussing over every car Ive ever owned for 30 years, and its done me no harm. If I wanted to just drive a car I would have just bought a Taurus.

bakermel1 said:

I purchased a 2016 SL in December of 2015. The first year I drove 75 miles round trip commute and charged 5 days a week. Since January this year commute is down to 22 miles round trip charging every couple of days. I have just lost my 3rd battery bar just under 27,000 miles. I have only quick charged 3 times. I don't leave it sitting charged. I really expected the battery to last longer. The battery really can't take the Phoenix, Az heat.

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Thanks for the update. Can you and other folks who have lost capacity bars on their 30 kWh Leafs please add your info to http://www.electricvehiclewiki.com/Real_World_Battery_Capacity_Loss?

The good news for you as long as Nissan didn't muck w/the capacity loss levels for each bar, you're going to definitely hit 8 bars before the 8 year/100K capacity warranty (for 30 kWh cars) expires and you might even hit it multiple times before expiration.

I don't think this has been posted yet, but on 6/9/17, https://www.facebook.com/groups/437741293059829/permalink/777567655743856/ reported a 2nd bar gone on a '16 30 kWh car at 17K miles. That person per FB lives in Florida.