The bar that should be lost but sticks around

Hi all -
I have a 2011 SL model with more than 25,000 miles and have been unhappily awaiting the loss of my first capacity bar, which I know is bound to come. The "problem" is, it hasn't come, and I can tell from my Leaf Battery App (or Leaf Spy, whatever it's called now) that I am at 86.5% total capacity (something like 56.2 AHr). So if the capacity bars are really disappearing for every 8% of capacity (approximately), then I should have lost that first bar long ago. I still have all 12 as of today.
So maybe I should be counting my blessings... but since I trust the Leaf Battery App more than the car itself, instead I'm wondering if the last software update is "softening" the lost bars to make customers happy rather than indicate real capacity loss. In other words, they set the capacity bar loss-rate as optimistically as they could, regardless of accuracy.
Anyone else experience this? Is it just coincidence that this softening might be happening when they implement a battery warranty program that relies on the lost bars to notify people when they qualify?
Best,
Josh

barsad22 said:

Hi all -
The "problem" is, it hasn't come, and I can tell from my Leaf Battery App (or Leaf Spy, whatever it's called now) that I am at 86.5% total capacity (something like 56.2 AHr). So if the capacity bars are really disappearing for every 8% of capacity (approximately), then I should have lost that first bar long ago. I still have all 12 as of today.

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Your assumption about 8% per capacity bar is wrong. See http://www.mynissanleaf.com/viewtopic.php?p=224446#p224446" onclick="window.open(this.href);return false;. I don't know where the table is now, off the top of my head.

And per http://www.mynissanleaf.com/wiki/index.php?title=Battery_Capacity_Loss" onclick="window.open(this.href);return false;

Note that per the Nissan Leaf Service Manual, the first capacity bar loss represents a 15% loss, while each subsequent bar represents only a 6.25% loss.

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barsad22 said:

I am at 86.5% total capacity (something like 56.2 AHr).
Josh

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You're lucky ... From what I've been reading this mark is around 55.1, that's where Im at today so I should be down to 11 CB very soon.

Actually 55.1 AH for the San Diego area, where are you located? That changes everything.

Sacramento, CA area 55.5% if that's you.


Will let you know tomorrow.

Fred

My AHr dropped all the way to 54.44 in the heat of August and had rebounded to 54.84 with the cooler temperatures, and then I lost a bar (9/26/13). I lost my bar with my battery temps. the lowest since last spring, 4 temp. bars, between 53-57 degrees, at the time I lost cb 12. It took 26.5 months of driving the car and 41,124 miles. I also quick charged 189 times (25 to 100%, 89 to 80% or 80+, & 78 20-75% range).

Your car is actually displaying right, the first bar is lost at 85%, each proceeding bar is lost every 6.25%. So at 86.5%, you are 1.5% away from loosing the first bar. Your car is displaying correctly

It's 15% for the first and 6.25% for all the rest (yes, it does not add up to 100% since the capacity bars do not go all the way to zero)... It also might not be quite accurate if he has not had the P3227 update done.

cwerdna said:

Your assumption about 8% per capacity bar is wrong. See http://www.mynissanleaf.com/viewtopic.php?p=224446#p224446" onclick="window.open(this.href);return false;. I don't know where the table is now, off the top of my head.

Click to expand...

I also have a 2011 SL with 50K on it and no lost bar. I've noticed a range drop but it's hard to say if it's 15 or 10 or even 20%... I don't have any Ah or Gids recording. Maybe I try to get some data next time I go to a Bay Area LEAF meeting from someone who has a reader. BTW, I got the latest update during my 45K visit (it was more like 47).

Here is a fun little graph showing my true State-of-Health along with when I lost each of the bars (set at a Y value equal to what the SM indicates are the SOH thresholds). It is a little spotty since we only recently learned how to read the SOH but I was able to go back to old logs and fill in a few older spots. My cap bars and SOH were reset to 12 and 100% twice in the car's lifetime on 8/10/2012 & 7/10/2013 (got the P3227 update on 7/10/2013). You can see how long it takes for the bars to catch up. If I extrapolate on a time constant curve (negative exponential), it looks like I can expect to lose the 3rd bar again some time around Christmas. Based on the linear loss of SOH, I can expect to lose the 4th bar (threshold is the bottom of the graph) around Feb next year. SOH did bump up with the P3227 update but this does appear to be a valid correction since the data now follows the general trend better.

Thanks for the education, I didn't know the first bar drops at 15%, with 6.25% for each bar after... I actually would prefer it if Nissan just made each bar count for the same capacity, why does Nissan want to fool the majority of Leaf owners who don't know this piece of information? Someone who made the logical assumption like me that each bar is equal and doesn't have a reader to prove otherwise thinks they have 92% capacity when it's actually 85. I suppose they reason that even new cars don't register at 100% capacity, but then why not just count down from 96 or whatever the real capacity max is.
My car is in the Bay Area, and I know location changes the equation (I've seen Stoaty's spreadsheet). I had no idea "solar loading" was a real factor, I always assumed that since Bay Area temps (in Berkeley, anyway) never get far above 85 that parking in the sun wasn't a problem.

Best,
Josh

Oh, they are not going to make that first bar linear! :lol:

I'm surprised it's not 25% for the first bar and 75/11% for the rest.
I'm at 84% now; still have all the Bars.

I lost about 17% all at once a couple months back ( I have a couple of meter systems).
Nissan was OK with that, even though it was all at once.
If I could intentionally degrade the battery at this point, I would, before they start to get "rebuilt" ones that only have to meet the requirements of the exchange.
I figure if I got one now, it would have to be New!

I'm waiting for the next "Software Update" that changes that first bar to... like 35% :roll:

Some of us speculated the 15% was to get most leases back with all the bars. So much for that theory.

Of course, a 20% loss in 5 years was supposed to be the "typical" loss, with accelerated losses only affecting an extremely tiny number of people under extremely hot conditions (the infamous 5%, which fell outside the 95% design specs).

We all know how well that's turning out, don't we.

Though this is a bit tangential, and I realize someone is going to link me to the 10 other times it has been discussed (am I the only one that finds the Search feature unusable?), can we start a "Do's and don'ts" list on how the typical owner can preserve battery? I can geek out just like everybody else and read technical details about DODs, temp-deltas and look at spreadsheets with multiple data points, but sometimes it helps just to have a non-technical list. I'll start this based on my limited knowledge, and maybe others can correct me, add and subtract (and it would be great if a moderator put the final list as a "permanent" first post on the main board). I'd like to see consensus, so let's not argue over fine points that are only subjective, we should stick to established practices.

Preserve your Leaf Battery

DO
Keep your battery at between 30% and 40% SOC whenever possible, especially when sitting for long periods.
Park in a temp-controlled garage, or failing that, the shade, whenever possible.
Have your timer always set to 80% charge, and charge to 100% only when needed.
Save a charging cycle if you think you can go two days on one charge.
Keep the SOC between 20% and 80% as much as possible.

DO NOT
Quick charge, unless you need to for a daily commute (expect more degradation).
Discharge the battery down to single-digit SOC unless you absolutely have to.
Park in direct sunlight during the summer.
Let your Leaf sit at 100% charge for more than 12 hours without use.

barsad22 said:

Preserve your Leaf Battery

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95% keep the battery as cool as possible. 5 bars or less is preferred. 7+ is bad bad bad.
10% don't leave the vehicle near 0% or 100% for extended periods.
5% drive moderately.

% provided by GOM

Weatherman said:

Of course, a 20% loss in 5 years was supposed to be the "typical" loss, with accelerated losses only affecting an extremely tiny number of people under extremely hot conditions (the infamous 5%, which fell outside the 95% design specs).

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I think they did a good job with the estimate, they just accidentally switched the numbers. 5% will last for 5 years with only a 20% loss or less, the other 95% will reach 20% capacity loss much sooner.

In the end, the biggest we found to affect battery health is heat and cycling.

Sitting in a hot asphalt parking lot outside bakes that battery! Even being able to sit it in partial shade helps a bunch (I found that one out). From my experience, ambient temperature played some roll, but hot the heat of the asphalt does more to change the battery temperature (i.e. see all the people that cooled their garage to still loose capacity).

Secondly is cycling. The more you charge (and discharge) the more life of your battery is lost (i.e. the more miles you put on your car). This usually isn't preventable but the lost increase expoentially from the heat.

Charging to 80% or keeping at mid SOC did not slow down nor prevent arizona cars and their loss, which would indicate this factor only helps minimally

Not QCing again doesn't seem to have as much affect either (similar to 80% charge). The problem with the QCing is NOT the QC itself, but the heat caused by charging so quickly. Topping off via QC to >90% and multiple QCs per day can increase your battery temperature quickly. So the rule should more likely be - avoid QCing during the summer (if possible), avoid topping off by QC (if possible), and avoid multiple QCs per day (if possible). QCing during the winter should even be benefical to heat the battery to get better range!

I am also still waiting for my first bar to drop off. Here's my latest details from the Leaf Spy App:

2011 Silver SL - Mfg 8/11 - Purch 6/12
8450 miles
12 Bars
4.6kWh avg
229 GID at 100%
193 GID at 80%
54.72Ahr
83.42% CAP
68.16% Hlth

I got the P3227 update back in July, so that's not currently affecting any readings. But my amp hours and capacity are definitely below anyone else who has recently lost a bar and had the app to measure the data.

Here's an updated list, based on the feedback above:

Preserve your Leaf Battery

DO
Park in a temp-controlled garage, or failing that, the shade, whenever possible.
Have your timer always set to 80% charge, and charge to 100% only when needed.
Save a charging cycle if you think you can go two days on one charge.
Keep the SOC between 20% and 80% as much as possible.
Keep your battery at between 30% and 40% SOC when sitting for long periods.

DO NOT
Park on hot asphalt parking lots during the summer.
Park in direct sunlight during the summer.
Discharge the battery down to single-digit SOC unless you absolutely have to.
Let your Leaf sit at 100% charge for more than 12 hours without use.

barsad22 said:

Here's an updated list, based on the feedback above:

Preserve your Leaf Battery

DO
Park in a temp-controlled garage, or failing that, the shade, whenever possible.
Have your timer always set to 80% charge, and charge to 100% only when needed.
Save a charging cycle if you think you can go two days on one charge.
Keep the SOC between 20% and 80% as much as possible.
Keep your battery at between 30% and 40% SOC when sitting for long periods.

DO NOT
Park on hot asphalt parking lots during the summer.
Park in direct sunlight during the summer.
Discharge the battery down to single-digit SOC unless you absolutely have to.
Let your Leaf sit at 100% charge for more than 12 hours without use.

Click to expand...

This probably belongs in a new thread with an appropriate topic name so people can find it easily when they're looking for something like that. You can also add it to the Wiki (see link in header above).

Preserve your Leaf Battery

DO
Live in the Pacifc Northwest

DO NOT
Live anywhere hot.