Discuss data from the LEAF Battery app, and Comparisons

[DaveEV]

The app is setup incorrectly.. the shunt order is 8421, not 4812 as you have it configured.

Interesting - the default is 4812 so I guess we need to get Turbo3 to update the defaults in the app. Or maybe the latest version has 8421 and when you update it doesn't change the previous value?

 

[palmermd]

The shunt order is used to properly relate which shunts are “on” to the correct cell pair on your phone display. If you know a little about bit masking, that is essentially what this setting is changing. If you’re not too interested in shunting (red cells vs green cells) then leaving this setting will not change the rest of your data.

We have the option to change it because we didn’t know the correct bit order early on. Allowing each user to change it allowed more people to try different settings and see which one gave the best data. Perhaps in a future release, the default will be set to 8421.

Sometimes after a full charge you may notice that after powering up the car it takes a few seconds for all the shunts to turn on. As the shunts turn on you can witness the voltages drop.. it goes from left to right (cell #1 to cell #96) and takes a few seconds. It's kinda cool. The pattern will persist for several on/off drive cycles as the BMS slowly bleeds down those particular cells.

Thanks FairwoodRed and GregH, I guess I need to set mine properly as well since I still have it on the default setting. Not that it matters much, I actually don't see much green to red color shifting going on and when I did, I did not pay too much attention to it...perhaps this is part of the problem with my pack.

 

[GregH]

So I've got a 2013 loaner and yesterday I caught it at the very end of a 6.6kW charge.. Like many other 2013s the Ah capacity is stuck at 67.3620Ah. The Health over the last few days has oscillated between about 110.00% and 110.50% (perhaps over a certain health the corresponding Ah capacity is above 67.3620 and that is some sort of cap). Has anyone seen more than 67.3620Ah?

Anyway what I found interesting was that as the charger tapered.. it REALLY tapered.. down to less than an amp with over an hour (according to the car) to finish. I took this photo while it was still ramping down.. (about 4.8A here)

Note the Gids at 284 and the SOC at 97.2999... I watched it taper down for a good 20 minutes and neither value budged.. Perhaps 284 Gids and 97.2999% SOC are also upper limit? This car has less than 1500 miles on it.

 

[jguenst]

So I've got a 2013 loaner and yesterday I caught it at the very end of a 6.6kW charge.. Like many other 2013s the Ah capacity is stuck at 67.3620Ah. The Health over the last few days has oscillated between about 110.00% and 110.50% (perhaps over a certain health the corresponding Ah capacity is above 67.3620 and that is some sort of cap). Has anyone seen more than 67.3620Ah?

Anyway what I found interesting was that as the charger tapered.. it REALLY tapered.. down to less than an amp with over an hour (according to the car) to finish. I took this photo while it was still ramping down.. (about 4.8A here)

Note the Gids at 284 and the SOC at 97.2999... I watched it taper down for a good 20 minutes and neither value budged.. Perhaps 284 Gids and 97.2999% SOC are also upper limit? This car has less than 1500 miles on it.

I have a leaf with less than 500 miles ant the Ah capacity is only 61

 

[dm33]

I have a leaf with less than 500 miles ant the Ah capacity is only 61

Took delivery last day of May. Highest Ahr capacity I've had on my 2013 after 2 weeks was 63.39, 95.67%. Since then its dropped to a low of 61.59 Ahr (92.82%), then bounced up a little to 62.59 Ahr (94.46%).

 

[DaveEV]

Anyway what I found interesting was that as the charger tapered.. it REALLY tapered.. down to less than an amp with over an hour (according to the car) to finish.

Very interesting. Would be insightful to try to log a 80-100% charge in the following scenarios:

1. '11-12 LEAF, 240V/16A
2. '13 LEAF, 240V/16A
3. '13 LEAF, 240V/30A

Logging parameters would include power drawn from the wall, pack voltage, CP voltages, GIDs and SOC.

Heck, just power from the wall would be interesting (should look into getting data from the data-monitor in the Blink - might be able to tap into it without affecting the rest of the Blink easily and with so many people having Blinks should make it easy to capture data from multiple cars). Seems like the '13 really tries hard when charged to 100% to really balance the pack. On the '11-12 on 240V/16A it takes only 15-30 minutes from start of taper to finish charging.

 

[Weatherman]

Data from a toasty, South Florida, one-bar-lost LEAF to add to the discussion. I never had any type of Gid meter, so I don't have anything to compare it to, but the results look pretty close to what I'd expect (although I thought the common knowledge was one bar loss = somewhere around 16% capacity loss):

Battery Status: 57.45 AHr, CAP=86.71%

Nice, uniform voltage across the cells: min 3.847; ave 3.858; max 3.865; SOC 36.3% (94 gids)

And, as expected, the battery is very warm, between 89 and 90F.


Air temperatures, down here, have, basically, been in the 80s at night and lower 90s during the day for the past couple of months.

 

[vrwl]

Data from a toasty, South Florida, one-bar-lost LEAF to add to the discussion. I never had any type of Gid meter, so I don't have anything to compare it to, but the results look pretty close to what I'd expect (although I thought the common knowledge was one bar loss = somewhere around 16% capacity loss):

Battery Status: 57.45 AHr, CAP=86.71%

Nice, uniform voltage across the cells: min 3.847; ave 3.858; max 3.865; SOC 36.3% (94 gids)

And, as expected, the battery is very warm, between 89 and 90F.


Air temperatures, down here, have, basically, been in the 80s at night and lower 90s during the day for the past couple of months.

Have you already had your P3227 software update done on your car? That might explain the higher CAP% than what you're expecting to see. Mine rose 5% (granted, it is reported as a temporary increase) after the update was applied to my car last week.

 

[Weatherman]

Have you already had your P3227 software update done on your car? That might explain the higher CAP% than what you're expecting to see. Mine rose 5% (granted, it is reported as a temporary increase) after the update was applied to my car last week.

Yes, back on June 7th. It still has only 11 bars, but it did, and still does, seem like the car has more range from 80% to LBW than it did before the update.

 

[Weatherman]

One interesting tidbit...

Stoaty's battery degradation model predicts a capacity of about 87.8% at one year and 9,300 miles for Ft. Lauderdale (4 miles/kwh with 5 days a week in the sun). 86.7% sure is close.

I don't know why the first capacity bar dropped so prematurely on my car and didn't come back after the software update. 11 months and 8,300 miles is really unusual to lose the first bar, even for a persistently warm climate like South Florida.

 

[Weatherman]

A couple more, interesting data points:

After I overrode the charging timer last night and allowed the car to charge to 100%, according to the app, it only charged to 91.7%. This may be why the battery app shows a capacity of 86.7%, while the car's capacity gauge is showing 11 bars. A 100% charge is stopping well short of even 95% full.

As far as temperatures are concerned, the maximum recorded was between 93F and 95F after the charge completed, shortly before midnight. The minimum this morning, with the car sitting outside all night in upper 70s air temps, was 85F to 87F.

 

[Stoaty]

One interesting tidbit...

Stoaty's battery degradation model predicts a capacity of about 87.8% at one year and 9,300 miles for Ft. Lauderdale (4 miles/kwh with 5 days a week in the sun). 86.7% sure is close.

Yes, the battery aging model is doing a pretty good job of predicting capacity loss... fortunately or unfortunately depending on your location/climate.

 

[LEAFer]

Installed beta version this morning. Ahr= 55.76, Cap=84.16%, Health = 70.77%.

For details see http://www.mynissanleaf.com/viewtopic.php?f=31&t=10653&start=37" onclick="window.open(this.href);return false;

 

[mwalsh]

I downloaded the "Health" beta yesterday (or was in Wednesday) and got it up and running this morning.

Readings are AHr=53.30 CAP=80.45% Hlth=76.57%

AHr and % readings since first getting the app up and going on June 22nd:

6/22: AHr=54.07 CAP=81.61%
6/24: AHr=54.01 CAP=81.52%
6/25: AHr=54.12 CAP=81.68% (weird that it went up!)
7/11: AHr=53.16 CAP=80.23%
7/12: AHr=53.30 CAP=80.45% (went up again)

I'm not using the app and phone every day - finding it too difficult to read the screen with polarized sunglasses on, so sticking with the tried and true Gidometer for daily use.

 

[LEAFer]

I downloaded the "Health" beta yesterday (or was in Wednesday) and got it up and running this morning.

Readings are AHr=53.30 CAP=80.45% Hlth=76.57%

Installed beta version this morning. Ahr= 55.76, Cap=84.16%, Health = 70.77%.

For details see http://www.mynissanleaf.com/viewtopic.php?f=31&t=10653&start=37" onclick="window.open(this.href);return false;

Wow ! How come my higher capacity LEAF is so much less healthy ?

 

[TomT]

I have given up trying to make any sense of all this. Here are my latest after an 80% charge... My "Health" is worse than either of yours...

I downloaded the "Health" beta yesterday (or was in Wednesday) and got it up and running this morning.
Readings are AHr=53.30 CAP=80.45% Hlth=76.57%

Installed beta version this morning. Ahr= 55.76, Cap=84.16%, Health = 70.77%.
For details see http://www.mynissanleaf.com/viewtopic.php?f=31&t=10653&start=37" onclick="window.open(this.href);return false;

Wow ! How come my higher capacity LEAF is so much less healthy ?

 

[mwalsh]

Can someone remind me where "health" comes from?

 

[GregH]

Can someone remind me where "health" comes from?

Active CAN data from the BMS, group 1, line 5, bytes 3 and 4... Just before the precision SOC (bytes 6, 7, 8) and AHr capacity (line 6, bytes 3, 4 and 5)... Just reading the raw numbers and trying to figure it out. There's a whole thread ("Capacity vs health") on this...
http://www.mynissanleaf.com/viewtopic.php?f=44&t=13247

 

[Weatherman]

I think what I've found the most revealing about data I've gathered the past few days is that a 100% charge is not really a 100% charge and an 80% charge is not really an 80% charge.

The 80% charge not really being an 80% charge explains the infamous 9-bar-on-an-80%-charge thing people have tended to see right before losing a capacity bar. I think it's more temperature related. If I'm getting battery temperature readings close to 90F, it's more likely that an 80% charge will end somewhere around 79 to 79.5%.

100% charges are, of course, even more of a misnomer. Even under the best of circumstances, a 100% charge really ends around 95%. With my battery being toasty warm, a 100% charge ends more like at 91 to 92%.

 

[JPWhite]

Lost my first capacity bar this morning

LEAF Battery app shows health rating of 80.94% and 55.75Ah