Had the P3227 reprogram done today: interesting results.

[RegGuheert]

For reference, here is what the P3227 spike looked like on our LEAF:

For some reason there are still 12 capacity bars showing at 55.12 Ah. It has been as low as 55.01 Ah.

 

[TickTock]

For reference, here is what the P3227 spike looked like on our LEAF:

For some reason there are still 12 capacity bars showing at 55.12 Ah. It has been as low as 55.01 Ah.

It took 6 months for my bars to catch up with SOH. Tip: Do not get any service 6 months prior to expecting to make a warranty claim. ;-)

 

[dgpcolorado]

For some reason there are still 12 capacity bars showing at 55.12 Ah. It has been as low as 55.01 Ah.

Since it seems that most people losing the first bar do so at well below -15%, which I will estimate at 56.3 Ahr, my guess is that it takes some time below that threshold before the car will drop the first bar, due to built-in hysteresis. By that time the measured Ahr has continued to drop some more. Perhaps the Ahr needs to be below 85% for a month (or two) before the first CB drops.

In a similar vein, the my impression is that the Ah displayed also seems to lag the actual change in the battery. My battery has cooled off the last week (13ºC-19ºC range) but some driving in warm weather just prior to that now seems to be getting displayed, since the capacity has been dropping sharply in recent days. If the battery temp continues to be low I expect the drop to level off soon and stay that way until spring, as happened last year.

Just guessing, though. A complicating factor is that I haven't charged to 100% in over a month and it may be that my battery is just drifting out of balance and I am looking at an artifact of that.

 

[DaveEV]

My round trip commute is only 50 miles so I am not hurting for range.

With only ~15 kWh from the wall, you must be getting some amazing efficiency to get 50 miles with room to spare with a very consistent commute? 55 miles is about the most I rely on at 65 mph, and that's down to LBW. Though since I got new tires I can probably knock 5 miles off until they fully break in.

I suspect the recent phenomenon is just a coincidence. However, the timing certainly caused me to raise an eyebrow.

If you're not actually draining it to zero when measuring the energy from the wall, is it possible it's instrumentation error? It's been hypothesized that capacity may rapidly drop off at some point, but I don't think it's been actually seen before.

In a similar vein, the my impression is that the Ah displayed also seems to lag the actual change in the battery.

Yep, I notice this, too.

A complicating factor is that I haven't charged to 100% in over a month and it may be that my battery is just drifting out of balance and I am looking at an artifact of that.

While I do see more shunting after a 100% charge, there doesn't seem to be much difference in the quality of balance after a 100% charge for me. I keep on meaning to do some sustained 100% charging to see if that will help balance my pack more, but I'm waiting for my pack to get into the low 70F range, first. Still in the upper 70F range after a 80% charge in the morning.

 

[tivollix]

@RegGuheert

It is interesting how similar our batteries are... Same usage pattern and same degradation.

Capacity evolution, the spike in capacity is the P3227 update:

For reference, here is what the P3227 spike looked like on our LEAF:

For some reason there are still 12 capacity bars showing at 55.12 Ah. It has been as low as 55.01 Ah.

 

[mwalsh]

I just had the update done, my spike was a massive 7AHr!

 

[TomT]

I don't think I've heard of that high a bump before... It'll be interesting to see how long it takes to return to "normal..."

I just had the update done, my spike was a massive 7AHr!

 

[palmermd]

I just had the update done, my spike was a massive 7AHr!

Think of all the places you can go now with an extra 20 miles of range.

 

[RegGuheert]

For some reason there are still 12 capacity bars showing at 55.12 Ah. It has been as low as 55.01 Ah.

Since it seems that most people losing the first bar do so at well below -15%, which I will estimate at 56.3 Ahr, my guess is that it takes some time below that threshold before the car will drop the first bar, due to built-in hysteresis. By that time the measured Ahr has continued to drop some more. Perhaps the Ahr needs to be below 85% for a month (or two) before the first CB drops.

Our LEAF has now been below 56.3 Ah for a bit over six months, but the 12th capacity bar refuses to disappear:

Currently, it is stuck at 54.57 Ah. It has not reported a different value (not even by 0.01 Ah) since the beginning of 2015.

So, I have to conclude that one or more of the following are true:

1) The P3227 update that I received lowered the thresholds for the bars disappearing. (Yes, I understand that others have dropped bars after P3227 at values above 55 Ah, but nothing tells me that the P3227 update could not have changed since those cars were programmed.)
2) It takes more than six months for capacity values to settle following the P3227 update. Perhaps it is related to the number of starts rather than time. (Our LEAF does not get driven every day.)
3) Our capacity is going back up, but the new firmware that came with P3227 does not allow it to report a rise more than the 0.15 Ah it has already shown.

But I must say that it is interesting the capacity has stopped dropping in the cold weather. Frankly, that seems much more reasonable than what happened last winter when the capacity dropped steadily through that very cold winter. I think it is entirely possible that the reduced cold-weather regen has prevented plating of elemental lithium that was occurring in the cold weather with the old BMS regen code. If that is the case (and I'm not sure we will ever really know), then the reduced regen is quite a bit more tolerable to me.

 

[dgpcolorado]

...Currently, it is stuck at 54.57 Ah. It has not reported a different value (not even by 0.01 Ah) since the beginning of 2015...

I routinely see this. My capacity has been at 56.3589 Ah for well over a month and it remained at a constant figure last winter for five or six months. I assume that once the battery is consistently below a certain temperature, perhaps 12-15ºC, the capacity remains constant until it warms up again in the spring. I did notice that my capacity dropped in November but it seemed related to the lag time in reporting, which may be several months.

I suppose that it is possible that one of the changes made by P3227 was an increase in the hysteresis of the capacity readings or bars and that pre-update battery packs would drop the bar at higher readings. Just a guess though.

I would speculate that one of the reasons degradation is much lower in colder climates — think Norway — is that below a certain temperature, degradation essentially stops. Places with a very short warm season would have slower capacity loss. Places with a long warm season, such as Florida or Hawai'i would have increased degradation despite not getting anywhere near as hot as Phoenix. The battery is over the degradation threshold temperature 24/7/365.

A complicating factor in trying to figure out the temperature threshold below which degradation stops is that driving, especially at high power levels, and charging, especially quick charging, greatly increases the battery temperature; I routinely see increases of 8ºC or more. I presume that my degradation has been greater than would be expected by my cool climate because of the high power levels needed to ascend steep hills all the time, which heats the battery a lot. People who engage in "spirited" driving would see much the same thing, as compared to easy-does-it hypermilers.

 

[vrwl]

Our LEAF has now been below 56.3 Ah for a bit over six months, but the 12th capacity bar refuses to disappear

Reg, when I finally lost my 12th capacity bar, my readings were: 80% GIDS 189, 53.92 Ah, 82% SOH, 66.14 Hx

So you may still have a long way to go before you lose yours.

 

[RegGuheert]

Our LEAF has now been below 56.3 Ah for a bit over six months, but the 12th capacity bar refuses to disappear

Reg, when I finally lost my 12th capacity bar, my readings were: 80% GIDS 189, 53.92 Ah, 82% SOH, 66.14 Hx

Thanks, Vicki! I notice that your Hx is significantly lower than your capacity, just like mine is. Do you quick charge often, rarely or never?

So you may still have a long way to go before you lose yours.

Yeah, particularly since the Ah value stopped changing!

Can you tell me what month you got the P3227 update? I'm wondering if those of us who go the update later have lower thresholds.

 

[vrwl]

My P3227 update was done on 7-2-13, and I lost my 12th capacity bar on 2-1-14. I did a total of about 5 quick charges prior to the bar loss, so that really wasn't a factor. But I DID live in Texas at the time, so the heat was the issue for my car. We moved to PA a month and a half after the bar loss, in March 2014, and since that time, my capacity loss has slowed dramatically. Total capacity loss in the 1 year since the bar loss has been 0.6 Ah. Heck, I lost that much in a month in Texas!

 

[RegGuheert]

My P3227 update was done on 7-2-13, and I lost my 12th capacity bar on 2-1-14.

O.K. So you had your P3227 reprogram done pretty early on. That blows away my theory that some of us are losing our 12th bar well below the 55.25Ah level that many users see because of a change in P3227. Back to the old drawing board.

I did a total of about 5 quick charges prior to the bar loss, so that really wasn't a factor.

My point was that fewer QCs results in a lower value for Hx, so it fits. Is it right? Who knows?

Total capacity loss in the 1 year since the bar loss has been 0.6 Ah. Heck, I lost that much in a month in Texas!

That's encouraging, since I don't live too far from PA (about 45 miles from the southern border)!

I haven't lost so much as 0.01 Ah so far in 2015!

Who needs regen anyway?! /sarc off

 

[gbarry42]

I was catching up on the last few years of this discussion, and I noted with interest that I'm not the only one who thought that next capacity bar would be gone by now. I've copied drees' status line and put mine underneath for comparison:

Feb 2015: 36k 51.1Ah 216/179 GID
Feb 2015: 30k 50.7Ah 209/178 GID

I still show 11 capacity bars. His went to 10 last November. That should shoot full of holes, any theory I could come up with! I didn't know where to post this, and this thread seemed like a good place. Of course, now that I've outed it, that bar should be gone by morning

 

[gbarry42]

Of course, now that I've outed it, that bar should be gone by morning

Ding, ding, ding! Boy, I nailed that one! It was gone this morning! With that kind of luck...I think I'll go buy some more Tesla stock.

 

[essaunders]

Any new thoughts on this update? I'm due to take my car (2012 with 18kmiles, still 12 bars) in for my year three battery check ($39.95 supposedly) and get my brake fluid replaced ($109.95). I refused the update last year. Is there any reason to get the update now? At 6k miles annually in NH I'll never exercise the 'warranty'.

 

[mwalsh]

Any new thoughts on this update? I'm due to take my car (2012 with 18kmiles, still 12 bars) in for my year three battery check ($39.95 supposedly) and get my brake fluid replaced ($109.95). I refused the update last year. Is there any reason to get the update now? At 6k miles annually in NH I'll never exercise the 'warranty'.

I'm not sure it makes sense for you to do it. I wouldn't have, if there was no chance I'd be a warranty candidate.

 

[TimLee]

...I refused the update last year. Is there any reason to get the update now? At 6k miles annually in NH I'll never exercise the 'warranty'.

The only risk is if your on board charger dies from Nissan defective interpretation of the J1772 standards from an EVSE prior to warranty and any extensions you purchased running out.
But even then that appears to be Nissan's defect.
Most of the failures were GE EVSE.
But some indicate other brand EVSEs resulted in on board charger failure when power interruption happened and Nissan's software allowed the EVSE to put power to the on board charger in a shorted condition.

 

[essaunders]

...I refused the update last year. Is there any reason to get the update now? At 6k miles annually in NH I'll never exercise the 'warranty'.

The only risk is if your on board charger dies from Nissan defective interpretation of the J1772 standards from an EVSE prior to warranty and any extensions you purchased running out.
But even then that appears to be Nisssn's defect.
Most of the failures were GE EVSE.
But some indicate other brand EVSEs resulted in on board charger faileure when power interruption happened and Nisssn's software allowed the EVSE to put power to the on board charger in a shorted condition.

At over 3 years old I believe I'm past basic warranty but still in the 6 year 'EV System' warranty (would cover charger).

I'll have to research this EVSE incompatibilty and weigh that risk against a daily impact of reduced regen. My day starts every day with a downhill from my house. I only charge to 80% mostly to have regen on that first leg.