LeafSpy red bars and capacity loss

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calverajarda

Member
Joined
Jan 27, 2018
Messages
13
Hi,
i have trouble.
From date buying my car (used) i have capacity cca 64Ah. It was winter time, i charged to 100% with onboard timer due small range.
When charged to 100% on LeafSpy ale bars are balanced (blue) (shunts off).
When was weather less colder i changed charging to 80% with onboard timer.

In cca 10 days i checked LeafSpy and i have loss cca 5Ah on battery. Leaf Spy displays mostly red bars (1-4 blue) when i charged to 100%.
I tried:
Cca 5x 100% charge - still all red capacity 59Ah
Some QC - still +/- 59Ah still all red
Discharge to turtle and then 100% charge - still 59Ah, all red

Capacity loss in 10days 5Ah is bad. But not balanced (shunts) cells after 5 100% charges too.

Any idea?

9pp2le.png

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9 mV of voltage difference is very low, which is very good, so don't worry about that.

The capacity loss is likely not real. Instead, it is more likely that the seller recently reset the Battery Management System (BMS) just before you purchased the vehicle to make it appear that it had more capacity than it actually does. You will have to wait to find out where your capacity actually lies.
 
RegGuheert said:
9 mV of voltage difference is very low, which is very good, so don't worry about that.

The capacity loss is likely not real. Instead, it is more likely that the seller recently reset the Battery Management System (BMS) just before you purchased the vehicle to make it appear that it had more capacity than it actually does. You will have to wait to find out where your capacity actually lies.
Agree on all of the above. I wouldn't worry about the blue vs. red bars (shunting or not).

However, there's no way in 8 days that a normal car (not reset) would drop from 98% SOH to 91 or 90%. Ditto for the amp-hour drop I see. So, agree that there was a reset done. It can take weeks or months for the # of capacity bars (and likely AHr, SOH and Hx) to return to the actual level, as the BMS/car re-learns the battery.
 
Ok, thanks :(
These are data from buying:
date/km/ahr/soh/hx
23.2./39036/64.19/98,15/96,1
23.3./41676/65.09/99.53/97.2
10.4./42976/59.65/91.2/88.66
29.5./47581/59.17/90.5/88.03

Its possible capacity loss with temperature? I mean not. To March was more colder.

I mean 4000km is long time to see battery reset. Its any idea to check if was battery reset done? By dealer?
Why are from capacity loss bars in LeafSpy red but balanced?

From 30.3.
2mr6vb5.png


Now is 100 charged cca 19,8kWh
 
calverajarda said:
I mean 4000km is long time to see battery reset.
I don't know how long it takes. It'll probably take longer to relearn if the car was down many bars to begin with.

I don't know the full chronology of http://daveinolywa.blogspot.com/2014/11/buyers-beware-this-is-must-read.html but that and the linked FB post states the car was bought in July (2014) with "all" capacity bars showing. By Nov 20th, 2014, the car was down to 9 bars. By sometime in December 2014, before the 7th (http://daveinolywa.blogspot.com/2014/12/update-saga-of-vin-222-resolved.html), it hit 8 bars.
calverajarda said:
Its any idea to check if was battery reset done? By dealer?
I've never heard of any method to know who did it. Dealer or whoever had it before can lie/claim ignorance.

calverajarda said:
Why are from capacity loss bars in LeafSpy red but balanced?
Those red and blue bars are showing module voltages, NOT capacity loss. Those will go down as the pack and modules discharge and up and it's charged. There should also be voltage sag under load, esp. heavy load (e.g. full throttle).

Turbo3 (author of Leaf Spy) has done some analysis and reverse enginering on the BMS, balancer, etc.: http://www.mynissanleaf.com/viewtopic.php?f=8&t=17470.
 
Yes, i know this. But it means - car must have real range equivalent to 8bars with purchase (displays 12 bars) if reseted in 8 bars.
When i purchased i have equivalent real range to new car. Now i have real range cca -10% and its coresponding with my capacity loss.

Here in Czech is more colder - not Californian weather.
Charging to 100% and drive. Not leaving car staying. When staying for long time charged to 50%. Not more that 1 QC in drive. Charging at night.
Its lot of Californian Leafs with battery fast degradation....

Yes, i know. Voltage is changing when load. I measure voltage when car staying - no load (very small load)
 
calverajarda said:
I mean 4000km is long time to see battery reset.
calverajarda said:
Here in Czech is more colder - not Californian weather.
I have noticed in previous winters that BMS does not change the predicted value of the remaining capacity during the cold of winter. Perhaps it was "holding" the value it had due to cold temperatures until it warmed up a bit.
 
cwerdna said:
calverajarda said:
Its any idea to check if was battery reset done? By dealer?
I've never heard of any method to know who did it. Dealer or whoever had it before can lie/claim ignorance.

This car has not changed in any significant way. The main change is in the estimates of the BMS or battery management system. This might have been due to a BMS reset, or might have been due to the estimate changing due to changing driving patterns and conditions.

Last fall, I briefly increased the capacity estimate in my car to the maximum value by just driving and charging in a specific pattern. So calverajarda's car might not have had a BMS reset to make the capacity estimate higher. So even if there was a way to find out if or when a BMS reset happened, that might not help as there might not have been one.

The estimated capacity will stay the same as long as the battery is cold. Now that your car is warming up, it is reporting a more accurate SOH and Amp hours and such.

The range predicted by the car (the GOM or "Guess-O-Meter") is based on this estimated capacity and recent driving history, and is less accurate at diagnosing the state of the car.
 
Ok,
and about red bars (shunts) in LeafSpy....
Any way to go them blue?
Why was before capacity loss blue and after loss red? Why can get them blue? (few 100% charging, discharge to turlte and then charge to 100%)
For me is strange capacity loss and red bars same time :(
 
calverajarda said:
and about red bars (shunts) in LeafSpy....
Any way to go them blue?(
Don't worry about it. Stop stressing over it. Heck, the shunt order (via settings) may not even be right and thus the representation could be wrong.

The ONLY thing you should worry about is if you have a range collapse issue like at http://www.mynissanleaf.com/viewtopic.php?f=9&t=21700. If you see 100+ mV difference at higher states of charge, that's abnormal.

(Side notes: Also see my comments at http://www.mynissanleaf.com/viewtopic.php?p=516652#p516652 and http://www.mynissanleaf.com/viewtopic.php?p=499102#p499102. Turbo3 lives a few miles from me and although we don't hang out with each other, I sometimes meet him at local EVents.

For more background info, Google for site:mynissanleaf.com cvli.)

However, I'm pretty confident the OP's car has been reset. I have NEVER seen moves of SOH from 98.xx% to 91.xx% in 8 days or even 60 days. Just before the 98.xx% reading it was 99.xx%. It will be interesting to see the range SOH settles between after another 1 or 2 months.
 
Thakns,
from buy i have one more capacity loss and then back to ok From 98,15 to 92,44 and then back. See attachement. Now is loss long time :(

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2mglhy0.png
 
calverajarda said:
Thakns,
from buy i have one more capacity loss and then back to ok From 98,15 to 92,44 and then back. See attachement. Now is loss long time

Have you done a DC quick charge around the time of the increase back to 98%?

OR

Did you have any unusual driving/charging around the time of the capacity loss?

SOH is an estimate, and it varies for many reasons.
 
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