80 percent charge setting yields 75 percent - why?

Hello all.
I have my charge timer set with no start time, end time of 4 a.m., and 80 percent charge. The last few days, charging has stopped at 9 bars / 75 %. The last time I charged to 100% (sometime last week) all twelve bars were showing.

Is the 9 bar / 75 % indicative of some loss of battery capacity? Or is there some other explanation?

Thanks,
Gary

http://www.mynissanleaf.com/viewtopic.php?f=30&t=8765" onclick="window.open(this.href);return false;

http://www.mynissanleaf.com/viewtopic.php?f=30&t=15570" onclick="window.open(this.href);return false;

http://www.mynissanleaf.com/viewtopic.php?f=27&t=13945" onclick="window.open(this.href);return false;

http://www.mynissanleaf.com/viewtopic.php?f=30&t=12679" onclick="window.open(this.href);return false;

brg2290 said:

... Is the 9 bar / 75 % indicative of some loss of battery capacity? ...

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Yes.
Brand new 2011 LEAF did not do this the first summer.
Started doing it the second summer in hot weather.
During second winter went back to charging to 10 bars.
Was mostly only doing 9 bars from third summer until lost first capacity bar late in the third summer.

This behavior gets REALLY annoying as you lose more and more battery capacity. I am down to 76% capacity now, so on the 2 days a week that I need every bit of range that I can get I set the timer for 100% charge, but most often end up with 92%. So, that's 92% of the 76%, or only 70% charge! :x I have to remember to wait until the timer charge is done, and then restart the charge cycle manually with my Open Wings app, so I get my full 76% by the time I have to leave. The rest of the week, my "80%" charge yields only 9 of the 10 normal bars. Its very frustrating. I don't know why Nissan thinks its too much trouble to make the charge % adjustable, like the Tesla S.

keydiver said:

... I am down to 76% capacity now, so on the 2 days a week that I need every bit of range that I can get I set the timer for 100% charge, but most often end up with 92%. So, that's 92% of the 76%, or only 70% charge! :x I have to remember to wait until the timer charge is done, and then restart the charge cycle manually with my Open Wings app, so I get my full 76% by the time I have to leave. ...

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Could you explain that a bit further.
Are you getting 12 of 12 status of charge bars?
Are you reading the 92% from LEAF Spy? If not where are you reading it?
If from LEAF Spy the 92% is fully charged and the LEAF will not charge any higher than this.
The 92% is of theoretical maximum, but LEAF will not charge to theoretical.
If you aren't at 12 of 12 bars, are you doing preheating or cooling?
That can prevent you from getting true 100%.
LEAF timers don't give you a real good means to be preheated and at completely full 12 of 12 bars.

If I charge (by timer) to 100%, I only get 11 bars charge, and usually Carwings reports it as 92%. The other days, with the timer set for 80% charge, I only get 9 bars charge, which I believe is around 75%, but I rarely check this.
This is how it looked this morning, after the 100% timer stopped, and I manually restarted it online:

This is how it looks right now, after it topped off to 80% when I got back home:

I don't do any preheating or cooling. This is just the lousy charging behavior that is getting worse as the capacity diminishes.
What is interesting is that if I manually start the charge to 100%, it usually goes the whole way to 100%. :?

keydiver said:

...
What is interesting is that if I manually start the charge to 100%, it usually goes the whole way to 100%. :?

Click to expand...

In a thread a long while back Ingineer pointed out that for the 2011 & 2012 cell balancing works much better if you don't have an end timer.
Just a start time or use the timer override button.
The failure to not charge to 100% may be associated with cell imbalance.

But it could be associated with battery degradation.

OK, if I don't use an end timer to charge to 100% on Saturday and Sunday mornings, how do YOU suggest having 100% charge by 8 AM??? When I first bought the car, almost exactly 3 years ago, little was known yet about how much charging to 100% contributed to degradation of the battery, so I had the timer set with a start time only, with Friday and Saturday evenings set to 100%, so I would have a full charge the next morning. But, as we started experiencing degradation, the thought was that the battery sitting all night at 100% might be the problem, so I changed to using a STOP time also. We now know that, although sitting at 100% does degrade the battery, the heat was much more of an enemy in south Florida.
Also, my cells are EXTREMELY well balanced, and my degradation has nothing to do with an imbalanced pack. I have only done 3 QC's, and never let the car sit for more than a couple hours at 100% if at all possible. The capacity loss is almost 100% heat related.

mwalsh said:

http://www.mynissanleaf.com/viewtopic.php?f=30&t=8765

http://www.mynissanleaf.com/viewtopic.php?f=30&t=15570" onclick="window.open(this.href);return false;

http://www.mynissanleaf.com/viewtopic.php?f=27&t=13945" onclick="window.open(this.href);return false;

http://www.mynissanleaf.com/viewtopic.php?f=30&t=12679" onclick="window.open(this.href);return false;

Click to expand...

LOL- you tried but of course no one takes the clue :roll:

EVDRIVER said:

mwalsh said:

http://www.mynissanleaf.com/viewtopic.php?f=30&t=8765

http://www.mynissanleaf.com/viewtopic.php?f=30&t=15570" onclick="window.open(this.href);return false;

http://www.mynissanleaf.com/viewtopic.php?f=27&t=13945" onclick="window.open(this.href);return false;

http://www.mynissanleaf.com/viewtopic.php?f=30&t=12679" onclick="window.open(this.href);return false;

Click to expand...

LOL- you tried but of course no one takes the clue :roll:

Click to expand...

Sometimes folks want to have a conversation, even if it is repeat. Nothing wrong with that.

Just like when someone says "charger" when asking about and EVSE. Most folks just answer the question since it is obvious what is being asked. A few bozo terminology sticklers just can't let it go and go on a rant mid-thread. I judge the stickler more than the "charger" guys.

oh yeah, charger, charger, charger, charger.

I'm bothered most by people who write "and" for "an". ;-)

I have been Irked by my car only charging to 79% when set to 80%, but having read these posts I think I'll just be grateful it isn't worse.

keydiver said:

OK, if I don't use an end timer to charge to 100% on Saturday and Sunday mornings, how do YOU suggest having 100% charge by 8 AM??? ...

Click to expand...

I just do a quick estimate of how long it will take to get to 100%.
My early rule of thumb with the 3.3 kW into the battery on board charger was half hour per status of charge bar.
That has decreased some with capacity degradation.
But best to leave plenty of time for cell balancing.

If you have LEAF Spy you can also calculate the time by determine the kWh you will be adding and divide by 3.3.
But that is a lot more trouble than half hour per status of charge bar rule of thumb.

It might finish one hour before departure sometimes, but it is usually closer than the end timer.
End timer sometimes finishes very early.
It is extremely cautious to be sure the LEAF charges on time.

EVDRIVER said:

LOL- you tried but of course no one takes the clue :roll:

Click to expand...

If you are referring to me, I just posted in this thread to rant, and I don't need to "take a clue". :roll: I'm not asking any questions about this behavior, or debating it. I'm just relating my experience, with 76% capacity remaining, for others to compare. I think it really poor programming on Nissan's behalf, when you are already suffering the effects of bad battery degradation, to also cut short your percentage of charge. There are many days when I REALLY need that 12th bar, but if I forget to manually start it at ~7:30 AM, I will only have an 11 bar charge.
What I may do, after Tim Lee's suggestion, is go back to only using a START timer. But, although that might be easy for Saturdays, where I start with an 80% charge on Friday night, and only need an hour to bring it up to 100%, I don't know how that can be made to work for Sundays. When I get home Saturday afternoon, the car will then charge to 100%, and sit all night fully charged. :? As we have discussed many times, the Leaf timers just aren't flexible enough for some schedules.

That behavior is indicative of some capacity loss. That's just an observation made by a large number of LEAF owners. There's not a lot of logic to it.

Fact is, 9 bars is 80%--you just have to use NissanMath(tm) to get it. Since there are 12 bars, each one represents 1/12 or 8.3% of a full charge (see disclaimers). So, the uncertainty on which bar to light can vary plus or minus half that. 9 of 12 bars is then 75% plus or minus 4%. Could be 71% or could be 79%.

When I charge to 80%, and read the gauge (LeafDD), it tells me 79.6%. I should see 10 bars, but I see 9. But it's so close that I could believe either answer. The important thing to know is that you are still charging to 80%, no matter what guesswork is appearing on the gauges.

Disclaimers:
1- The bars are not necessarily all the same "size"
2- A full charge isn't really 100%--it's limited to around 94% by the computer.
3- A "full charge" isn't what it was when your battery was new. But the "percents" are percents of what you have now.

keydiver said:

...But, although that might be easy for Saturdays, where I start with an 80% charge on Friday night, and only need an hour to bring it up to 100%, I don't know how that can be made to work for Sundays. When I get home Saturday afternoon, the car will then charge to 100%, and sit all night fully charged. :? As we have discussed many times, the Leaf timers just aren't flexible enough for some schedules.

Click to expand...

Not sure I understand why it would sit all night long fully charged :?:
If you have a Saturday timer active and it is already past the start time when you plug in the EVSE it will not start charging.
Unless you are leaving very early on Sunday, the timer will need to be set for Sunday :?:

TimLee said:

keydiver said:

If you have a Saturday timer active and it is already past the start time when you plug in the EVSE it will not start charging.

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Click to expand...

If there are no STOP times programmed into the timer, why would it not start charging Saturday evening when I get home? :?

keydiver said:

... If there are no STOP times programmed into the timer, why would it not start charging Saturday evening when I get home? :?

Click to expand...

I can see the logic that would justify that approach.
But is not how Nissan programmed a start only timer.
The Start only timer will not do anything if the Start time has already passed.

I think the rationale is that what a lot of people would use a Start only timer for is beginning charging just after the lowest cost time of day rate begins.
For that usage you would not want charging to start if you plugged in up during a high cost period of the day.