Capacity Loss on 2011-2012 LEAFs

[surfingslovak]

Here what was likely of the hottest days last year. Not sure how that jives with your experience.

 

[EdmondLeaf]

I am not able to do much about battery temp, but can try to keep SOC optimal. What will be better for the battery at high temp say 90 -100F. I am back home with 2 bars, charge to 50% and next morning to 80% or keep battery at 2 bars till charging late night early morning. I am assuming 50% is sweet spot.

 

[surfingslovak]

I am not able to do much about battery temp, but can try to keep SOC optimal. What will be better for the battery at high temp say 90 -100F. I am back home with 2 bars, charge to 50% and next morning to 80% or keep battery at 2 bars till charging late night early morning. I am assuming 50% is sweet spot.

Right, I would try to keep it around the middle of the battery gauge then. When in doubt, lower charge is better than higher charge in hot environments. I would not let the car sit with one bar or less for more than a few hours if I can help it.

 

[leafkabob]

I live in Phoenix and still have all 12 bars (for now). I have about 9500 miles after receiving the car on May 20, 2011. The car is typically charged to 80% with only the occasional 100% charge (maybe 20 in the past 12 months).

I am attempting to minimize the heat effect by setting my timer to begin charging at 3 am, which I figure results in the coolest period of time in my garage to charge. Been doing that pretty much since delivery.

Since our daily RT commute is only about 20-25 miles, it doesn't need a lot of time to charge to 80%. Never have QC'd and don't really plan to unless it is absolutely necessary.

The car is rarely, if ever, parked out in the sun. My wife and I both have big shady (though not necessarily cool) parking garages at work.

 

[Nubo]

]Mine is a 4-car garage attached to the house on 1 side (back side) with the garage doors facing north. I have only 2 cars are parked inside, 1 ICE & the Leaf, the other 2 spots are filled with storage stuff. The ICE car was used by my wife for work last summer so it does contribute some heat to the garage when it gets home in the evening, but since last fall until now, it's been much less used since my wife quit that job.

I don't think it benefits from the adjacent air conditioning that much, but at least there's very little evening sun exposure on all 4 sides. I actually have ample attic space above the garage and I cut out 2 1x1 foot square holes on the garage ceiling to allow hot air to escape into the attic out the roof vents. I'd say my garage is probably about 10-15 degrees cooler than the outside during the day.

You might want to check codes. Afaik, most require the garage to have an effective firewall separating it from the rest of the house. By cutting the holes you might have negated that.

 

[turbo2ltr]

Sorry I forget that I have to make the disclaimer that I am on the old firmware so I will have more bars for a given GID value.

But yes all the warnings happen at exactly the same GID values which didn't change with the new firmware.

When I pulled into the garage at 6:30 after driving around the neighborhood for 40 minutes, the dash said 101 deg. I had 7 bars on the temp gauge...which I was a bit surprised at since the car was in the shop all morning. But it was outside all afternoon. I was inside most of the day, guess it was hotter than I though out.

 

[Stoaty]

Right, I would try to keep it around the middle of the battery gauge then. When in doubt, lower charge is better than higher charge in hot environments. I would not let the car sit with one bar or less for more than a few hours if I can help it.

This brings up the question of how soon to charge back to 50% from, say, 25%. My Leaf sits in the sun 4 days a week for about 10 hours in the San Fernando Valley (Los Angeles). In the summer, I go up to 6 bars on the temperature gauge by 11:00 AM or noon. When I get home from work at 7:00 PM, I still have 6 bars on the temperature gauge. I understand it is better to let the battery cool some before recharging, but don't know the optimal time to wait--an hour, 2 hours 3 hours? At home the temperature is about 25 degrees cooler than the Valley on a typical hot summer day, so I get substantial cooling after some (unknown) period of time at home. Thoughts?

 

[surfingslovak]

When I pulled into the garage at 6:30 after driving around the neighborhood for 40 minutes, the dash said 101 deg. I had 7 bars on the temp gauge...which I was a bit surprised at since the car was in the shop all morning. But it was outside all afternoon. I was inside most of the day, guess it was hotter than I though out.

Hm, interesting, thanks for that! We noticed in early September last year, that there might be some correlation between a hot pack and a lower Gid reading. If this were true, it might explain the speed of the decline, and the sudden capacity drop in the group of affected vehicles. TickTock is apparently getting about 30 Gids less on a 100% charge than in February.

This brings up the question of how soon to charge back to 50% from, say, 25%. My Leaf sits in the sun 4 days a week for about 10 hours in the San Fernando Valley (Los Angeles). In the summer, I go up to 6 bars on the temperature gauge by 11:00 AM or noon. When I get home from work at 7:00 PM, I still have 6 bars on the temperature gauge. I understand it is better to let the battery cool some before recharging, but don't know the optimal time to wait--an hour, 2 hours 3 hours? At home the temperature is about 25 degrees cooler than the Valley on a typical hot summer day, so I get substantial cooling after some (unknown) period of time at home. Thoughts?

Aside from a cooler parking spot, there is not much more you can do. It can't get more conservative than this. If you wanted to see an appreciable difference in battery temperature, I would give it a few hours if possible. I'm basing this on my experience with the ActiveE, which has a battery temperature indicator on the center console. Perhaps Phil can comment, since the LEAFSCAN has the data you are looking for.

 

[EdmondLeaf]

Thank you for your advice. It is 7 h of rest and temp drop from 87 to 64 but still 6 temp bars. I believe temp gauge is not very accurate. Concerning charging I really do not like to charge twice, once from 2 bars to 6 and than to 10 but looks like that will be the best summer and not only summer battery protection program.

 

[GaslessInSeattle]

Don't forget that true 50% is more like 5 bars.

Thank you for your advice. It is 7 h of rest and temp drop from 87 to 64 but still 6 temp bars. I believe temp gauge is not very accurate. Concerning charging I really do not like to charge twice, once from 2 bars to 6 and than to 10 but looks like that will be the best summer and not only summer battery protection program.

 

[EdmondLeaf]

Don't forget that true 50% is more like 5 bars.

Exactly, therefore it looks like allowing car to stay with 2 bars for say 10 h should be acceptable because 2 bars is between 25 -30% SOC if I am correct

 

[EdmondLeaf]

It appears that high temp maybe responsible for AZ faster than expected capacity loss. After driving I think now more than 38KM TaylorSFGuy have new battery GID number.

Thanks to FairwoodRed for letting me borrow his GID meter. Over the last few days, my LEAF had readings varied between 272 and 280 at 100% charge. I appreciate his offer and takes some of the guesswork out of the equation.

 

[DaveEV]

Not sure if anyone already posted this but I just ran my car down to turtle.

Bar 3 went away at 41 GID
Bar 2 at 28
Bar 1 at 10

Compared to 54, 33, and 11 when the car was new.
LBW, VLBW and turtle all occurred at the normal points.

I am curious to see what 100% gets me tomorrow.

Will also be interesting to see what voltage your pack reads, too. Also, are you able to record time to charge and kWh used to charge? Is it also worth charging to 80% first, recording data and then charging the rest of the way and recording that data, too? (GIDs, voltage, time to charge, energy to charge)

Don't forget that true 50% is more like 5 bars.

Exactly, therefore it looks like allowing car to stay with 2 bars for say 10 h should be acceptable because 2 bars is between 25 -30% SOC if I am correct

FWIW - storage at 25-30% shouldn't be an issue - at least Toyota recommends that you store the PiP with the battery "empty" which is around that SOC, IIRC.

 

[RegGuheert]

So mark13 now makes 6 on this forum in Phoenix who have lost a capacity bar:

http://www.mynissanleaf.com/viewtopic.php?f=30&t=8833&start=110#p199473" onclick="window.open(this.href);return false;

Some in Phoenix have reported they are not there, yet.

Does anyone know what percentage of the posters from Phoenix six constitutes? Is it 1% or 50%.

Also, mark13 mentioned it was 112F in the shade yesterday.

 

[Herm]

It appears that high temp maybe responsible for AZ faster than expected capacity loss. After driving I think now more than 38KM TaylorSFGuy have new battery GID number.

In Kent, Washington

 

[surfingslovak]

Don't forget that true 50% is more like 5 bars.

Exactly, therefore it looks like allowing car to stay with 2 bars for say 10 h should be acceptable because 2 bars is between 25 -30% SOC if I am correct

FWIW - storage at 25-30% shouldn't be an issue - at least Toyota recommends that you store the PiP with the battery "empty" which is around that SOC, IIRC.

If you look at the SOC Check Sheet TomT found in his newly delivered car last year, Nissan seems to think that it's OK to store the car with three bars at the port of entry. It's also OK to ship the car to the dealer with two bars remaining. While I wouldn't run it down to turtle and let it sit like that for a week, and I prefer to charge up when the car reaches one bar, I have parked it overnight or at work with two bars remaining with no ill effects.

 

[edatoakrun]

I just bring this up because the 231 gids I get at 80% charge are not 80% of 281 gids, but 82,2%. And I remember Engineer (I think) saying that the 80% charge is the true 80% capacity of the battery unlike the 100% charge that is below the true 100% charge. As the 80% charge gid value is much more stable (I ALWAYS get 231 gids) it could be a better value to evaluate battery capacity.

Yes, when you set an 80% charge, it actually stops at 80% True SoC (Battery ECU's Reported SoC). When I do a charge to 100%, the numbers usually are 94%-95% SoC, with low SoC numbers also having lower Gids. (Keep in mind a Gid is 80 watt-hours)

So really the difference between "80%" and "100%" is actually only at most 15% not the 20% you'd expect.

Another good reason to only charge to 80% unless you need the "full" 94-95%. (You'd only be gaining at most 15%!)

-Phil

So a 80% charge should show the loss of total battery capacity more accurately than a 100% charge.

Would the 11 bar LEAFs please report their 80% charge results?

IMO, the timing of these bar disappearances could also reflect LEAF battery management, so the rapid drops in Gid counts reported by a few, could be somewhat misleading.

Is "full" (100%) still 94-95%, or are the Phoenix LEAFs trying to protect their battery from damage, due to the rising seasonal temperatures, by restricting the available charge percentage at the "100%" setting?

AFAIK, only Phil has reported the ability to measure this 94-95%, right?

In any case, it now appears temperature is a very important factor in loss of capacity.

Thank you for the 11 bar reports.

I live where the summer daytime temps are occasionally Phoenix-like where I drive (the Redding CA all time high temp record is 118 F) but its usually about 5-10 degrees cooler where I live, at 2000 ft. above the valley floor, and it always cools significantly at night. I will add try to avoid 7 bars on the battery temp gauge to my list of driving preferences.

A more accurate method of monitoring battery temp would probably be a good Idea for LEAF owners in hotter regions.

 

[Pipcecil]

I am curious if the bar drop from the Arizona people will start hitting the Texas people soon. We had a grueling summer last year with a record # of days of over 100 degree weather. In Dallas it was 70 days with a 39 day consecutive streak. Other parts of Texas had more 100 degree days. While it is not as bad compared to Arizona, it was definitely way hotter than normal. If it truely was the heat, you may start seeing Texas people reporting a loss of battery capacity...only time will tell.

 

[DaveinOlyWA]

we definitely need more data points. after all, we are supposed to be losing range. only question is when, how fast and what can we do to stop it?

has anyone lost capacity and lives in a moderate climate? maybe its a question of not charging beyond 90% if you live in 100º+ temps?

 

[turbo2ltr]

100% from turtle got me to 236 GID last night