Reset Capacity Bars

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Anybody who has access to Nissan's diagnostic software.

Most likely some of those Leafs have their batteries replaced.
Also some of those Leafs may come from colder regions.
Cold region degradation is slower, expect up to 5x slower.

Whoever is buying second-hand Leaf should test the range on highway.
It only takes an hour :)
 
Bottom line: you should never buy a used Leaf without putting some sort of GID meter on it (LeafSpy/LeafDD/etc).
 
DuncanCunningham said:
so when you plug in leafspy pro.. what number should you look at to see past any messing about with the bars?

Ahr and SOH are the only two I'd look at.

A new battery is 66 ahr, 1 bar lost around 50 ah, 2 bars lost around 46ah, 3 bars lost around 42 ah.

If the ahr are low and the bars are high they reset it, not a bad thing on its own but if you drop 4 bars in 60,000 miles or 60 months you get a free battery from Nissan, go over the months or miles and you don't.

You just want to know what you are really dealing with.

If the ahr is reasonable vs the bars on the dash then you can use SOH% as the easier to look at number on a 100% style scale but that number resets with the dash bars so use ahr to see if you can trust it then SOH% for a convenient percentage.

in table form

* Brand new - about 66.25 Ahr#
* Loss of bar 12 - between 53.75 AHr and 56 AHr
* Loss of bar 11 - between 49.75 AHr and 52 AHr
* Loss of bar 10 - between 45.75 AHr and 48 AHr
* Loss of bar 9 - between 41.75 AHr and 44 AHr

\#table is for 24 kWh packs, numbers would differ for a 30 kWh pack.
 
I used Leaf Spy to buy a 12 bar 2013 a month ago. SOH was 91% and AHR was 59, so I bought it. Now a month later im 87% SOH and 56 AHR. Not sure what's going on, but I didn't think it was reset based on AHR.
 
SurfHawk said:
I used Leaf Spy to buy a 12 bar 2013 a month ago. SOH was 91% and AHR was 59, so I bought it. Now a month later im 87% SOH and 56 AHR. Not sure what's going on, but I didn't think it was reset based on AHR.
colder weather, colder pack?
 
SurfHawk said:
I used Leaf Spy to buy a 12 bar 2013 a month ago. SOH was 91% and AHR was 59, so I bought it. Now a month later im 87% SOH and 56 AHR. Not sure what's going on, but I didn't think it was reset based on AHR.

Do you charge to 100% or 80%? If the latter, try checking it after a full 100% charge.
 
SurfHawk said:
I used Leaf Spy to buy a 12 bar 2013 a month ago. SOH was 91% and AHR was 59, so I bought it. Now a month later im 87% SOH and 56 AHR. Not sure what's going on, but I didn't think it was reset based on AHR.

How many miles do you get on full 100% charge before low battery warning? How many miles per kWh do you drive?
 
- Weather has been about the same since I bought it, maybe a bit cooler but we are still talking about southern california.

- First couple weeks I only charged to 80%. Then I read about re-balancing so I've been charging to 100%. However I have been using the charging timer, does that let it re-balance? Also, I am only charging via L1 at home, getting L2 installed next week. Some brief L2 charging in the wild a few times a week.

- I haven't tracked how many miles I get from 100% to LBW. I'm doing about 1/2 freeway driving at 65, and half city driving. I average about 4.2mi/kWh.

Here is a screenshot with Leaf Spy prediciting I'll get 72miles until 10% at 100% charge @ 4.4mi/kWh, which I'm happy with for what I thought was a 91% SOH car. EDIT: sorry for giant photos, will try to fix.
QOH3RAH.png


Here is my latest AHR and SOH
dDICljO.png
 
The charge cycle has to completely finish for the cells to be balanced. If it is being stopped by the timer, then they are not getting balanced. If it has not been done for a while, it may take four or five full charge cycles to get the cells fully balanced. Charge cycles require a lot more time to complete when using the L1 EVSE.
 
baustin said:
The charge cycle has to completely finish for the cells to be balanced...
I keep seeing this posted here, and it does not make sense. Look at first leafspy page. All those red lines are cells being bled off via balancing resistors in BMS. It happens all the time, regardless of the SOC. I think you are perpetuating the myth that you need to charge to full in order for balancing to occur.
 
- First couple weeks I only charged to 80%. Then I read about re-balancing so I've been charging to 100%. However I have been using the charging timer, does that let it re-balance? Also, I am only charging via L1 at home, getting L2 installed next week. Some brief L2 charging in the wild a few times a week.

If you don't set an end time with the timer, and the charge lights are all off when you unplug the car, then it is charging and equalizing fully. If you do set an end time, then it may not be doing so.
 
Keep in mind that the reset is "Clear Long Term Capacity Data".

It is possible that SOH which seems to correlate with capacity will take the longest to adjust back.
Maybe 4 to 8 weeks, 10 to 30 charge and discharge cycles plus miles driven.

AHr may adjust quicker.
But it could still be badly out of whack.

Hx which is based on pack conductance (inverse of resistivity) will likely adjust fastest.

Maybe one charge /discharge cycle, 100 miles since the BMS is measuring it much more directly.

I would look at that first.
 
I'm using the built in timer on the S trim, setting it to finish by 8am. Based on my utility reports, it's finishing by 6am. When I get to it at 8am, no blue lights are on and it's at 100%.
 
SurfHawk: Unless you battery usage range is really narrow (e.g. charge to 80%, go down to only say 60% then charge to 80%), I think it's somewhat likely you were a reset victim.

I posted my used '13 SV stats on a 5/2013 built car that I bought in mid-7/2015 at http://www.mynissanleaf.com/viewtopic.php?p=430825#p430825.

Of course the stats have generally crept downwards but not as rapidly as yours. Today (10/27/16), more than a year and 3 months later, my stats were these:
AHr: 57.09
SOH: 87%
Hx: 85.69%
odo: 38,749 miles

The stats fluctuate. About the worst recent stat I had was from 10/24/16:
AHr: 56,84
SOH: 86%
Hx: 85.15%
odo: 38,660 miles

Let's see if your keeps rapidly falling and you start losing capacity bars. I've still got all 12 of mine but am getting progressively closer to losing 1. What was the build month on your car? Where did it previously reside?
 
AntronX said:
baustin said:
The charge cycle has to completely finish for the cells to be balanced...
I keep seeing this posted here, and it does not make sense. Look at first leafspy page. All those red lines are cells being bled off via balancing resistors in BMS. It happens all the time, regardless of the SOC. I think you are perpetuating the myth that you need to charge to full in order for balancing to occur.

The equalization process (balancing) is done at the end of charge cycle, after the BMS determines charging is complete, and takes at least 25 minutes. The issue with cells that are not fully balanced only affects those that use the 80% charge option, or some other method to stop the charge cycle from completing. If you prefer to believe that the issue is a perpetuated myth, that is your choice.
 
baustin said:
The equalization process (balancing) is done at the end of charge cycle, after the BMS determines charging is complete, and takes at least 25 minutes. The issue with cells that are not fully balanced only affects those that use the 80% charge option, or some other method to stop the charge cycle from completing. If you prefer to believe that the issue is a perpetuated myth, that is your choice.

How do we know this?
 
AntronX said:
baustin said:
The equalization process (balancing) is done at the end of charge cycle, after the BMS determines charging is complete, and takes at least 25 minutes. The issue with cells that are not fully balanced only affects those that use the 80% charge option, or some other method to stop the charge cycle from completing. If you prefer to believe that the issue is a perpetuated myth, that is your choice.

How do we know this?

Start a charge cycle on a fully-charged battery and see how long it takes to complete.

Read the multitude of threads, going back to the beginning of MNL, that cover the charging and balancing topics in great detail.
 
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