Capacity vs Hx (Health)

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I haven't charged to 100% in several months. I'll take all the vitals next time I do. I charge to 65-70% every 2 or 3 days.

It's just sad that the health deteriorated 7-8 points in 10 days during the heat wave. Just not right :evil:
 
I have only recently tried the beta Leaf battery app with health status and have recorded the readings to 80% charge and 100% charge on two different days now. The car has not had the latest firmware update yet.

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The 80% charge showed 196 'Gids (69.8%) and the 100% charge showed 229 'Gids (81.6%) on the app when first turned on in the morning.

TT
 
My latest, conflicting results... This was after an overnight 100% charge which resulted in 230 Gids and a 95.3% SOC on my Lincomatic 1.3 Gid Meter...

aougy8.png
 
Do you QC alot? or have abused your pack with high temps? Interesting that yesterday at the meet, looking at Greg's LeafDD on his loaner 13 which I assume was almost new, his pack like mine was almost perfect.

I don't have a QC port, and have been taking excellent care of my pack and the Android app show perfect balancing across the cell almost.

I also have had the latest SW update done. Unless you're getting bad shunt readings, it almost seems like an anomaly.
 
Three QCs during the lifetime of the car... No particularly high temperatures... Typical cell imbalance is about 12Mv... 80% charges 95% of the time... Makes me even happier I leased.

JasonA said:
Do you QC alot? or have abused your pack with high temps? Interesting that yesterday at the meet, looking at Greg's LeafDD on his loaner 13 which I assume was almost new, his pack like mine was almost perfect.
 
I've only taken a few measurements at 80% charge after the upgrade, but I was happy to see that the capacity number went from 91 before the software upgrade to 94 after the software upgrade. I don't know where the extra 3 points came from, but I'll take it... the tech showed me something that said the software upgrade would make battery capacity measurements more accurate. Only 6% degradation after 21,000 miles and 2.5 years is much better than I expected, if these new numbers are to be trusted.

JG
 
Experience has shown that the numbers will drift back down to about what they were before the update after about a month or so...

barsad22 said:
I've only taken a few measurements at 80% charge after the upgrade, but I was happy to see that the capacity number went from 91 before the software upgrade to 94 after the software upgrade. I don't know where the extra 3 points came from, but I'll take it... the tech showed me something that said the software upgrade would make battery capacity measurements more accurate. Only 6% degradation after 21,000 miles and 2.5 years is much better than I expected, if these new numbers are to be trusted.
 
JasonA said:
I don't have a QC port, and have been taking excellent care of my pack and the Android app show perfect balancing across the cell almost.
That sounds like a mirror image of my LEAF. I would advise waiting until next summer before forming any opinion about the influence of charging habits and battery care on pack longevity. That said, Tom is a valued member of the secret battery abuser club. There is an invisible thread on the forum, which only members will get to see. Various tips and trick are exchanged there ;-)
 
Oh, you mean like the secret "fastest to discharge a pack" thread (100% charge, maximum heat, every accessory on, and full throttle until turtle during a Death Valley heat wave)???

surfingslovak said:
That sounds like a mirror image of my LEAF. I would advise waiting until next summer before forming any opinion about the influence of charging habits and battery care on pack longevity. That said, Tom is a valued member of the secret battery abuser club. There is an invisible thread on the forum, which only members will get to see. Various tips and trick are exchanged there ;-)
 
TomT said:
Oh, you mean like the secret "fastest to discharge a pack" thread (100% charge, maximum heat, every accessory on, and full throttle until turtle during a Death Valley heat wave)???
Yes, that one! Please don't forget the battery tanning sessions in Palm Springs (with four QCs en-route)!
 
Sorry if this has been covered before, but I just want to make sure... this "Health" is on the .25b Beta version of the Android app that isn't available in the Dropbox yet, right? And what is the Health number (all I can find is a "16-bit number I'm playing with" earlier in this thread)?
Again, sorry if I missed it in earlier posts.

JG
 
With one tiny exception (7/16/2013 13:49) ... my Ahr and SOH have been monotonically decreasing. See http://www.mynissanleaf.com/viewtopic.php?f=31&t=10653&start=37" onclick="window.open(this.href);return false;
 
Interesting data... but do you think the drop is a good indication of reality? It seems strange that your capacity would drop 6 points in one month (89 to 83), when in the previous 27 months you only dropped 11 points (100 to 89). This makes me wonder about the accuracy of the capacity reading (and what is the math behind "Health") on the Leaf Batt App.

JG

LEAFer said:
With one tiny exception (7/16/2013 13:49) ... my Ahr and SOH have been monotonically decreasing. See http://www.mynissanleaf.com/viewtopic.php?f=31&t=10653&start=37" onclick="window.open(this.href);return false;
 
GregH said:
What are the numbers in the first photo (other than Vpack)? If the 2nd photo is Ah Capacity and Health that seems odd.. 85.67% Health sounds really low for a 61.35Ah pack. Just the other day I was at 93.57% Health with 62.1166Ah Capacity in my car.

I'm seeing the same thing as GlennD ... the health dropped by ~15% when I got it back from the dealer, but the Ah didn't change much.
 
The drop so far is just the adjustment to Pre-P3227 levels. Look at the summary table at the bottom of this post: http://www.mynissanleaf.com/viewtopic.php?f=31&t=10653&start=34" onclick="window.open(this.href);return false;

Before the P3227 I was at 54.85Ahr (now "still" 55.29), and that was about (only) 800 miles and one month ago.

When I said "monotonically decreasing" I was referring only to the slow drop since the strong (fake) jump (increase) cause by P3227.

barsad22 said:
Interesting data... but do you think the drop is a good indication of reality? It seems strange that your capacity would drop 6 points in one month (89 to 83), when in the previous 27 months you only dropped 11 points (100 to 89). This makes me wonder about the accuracy of the capacity reading (and what is the math behind "Health") on the Leaf Batt App.

JG

LEAFer said:
With one tiny exception (7/16/2013 13:49) ... my Ahr and SOH have been monotonically decreasing. See http://www.mynissanleaf.com/viewtopic.php?f=31&t=10653&start=37" onclick="window.open(this.href);return false;
 
Ah capacity (in Ah) and health (in %) are the raw numbers direct from the car... No math involved.
The 2013 I've been driving for 12 days now has had Ah capacity pegged at 67.3620Ah but Health has jumbled around between 109% and 111%. The car charges consistently to 284 Gids and 97.2999% SOC on a full charge. At some point I'm guessing if the health drops below 105 to 108% then I might see the Ah capacity nudge downward.. If that happens in the next 9 days while I still have the car I'll let you know...
 
Greg, since you have a '13 to use could you please use Jim's App and see if you have true GIDs displayed correctly? Thanks! Mine changes drastically constantly (goes from 300 GIDs to 0 in a short time/ten minutes/5 miles) so it would be interesting to see if it happens on other '13s.
 
LEAFfan said:
Greg, since you have a '13 to use could you please use Jim's App and see if you have true GIDs displayed correctly? Thanks! Mine changes drastically constantly (goes from 300 GIDs to 0 in a short time/ten minutes/5 miles) so it would be interesting to see if it happens on other '13s.
I have a 2013 for the next week or so but no ELM nor any android devices..
 
GregH said:
LEAFfan said:
Greg, since you have a '13 to use could you please use Jim's App and see if you have true GIDs displayed correctly? Thanks! Mine changes drastically constantly (goes from 300 GIDs to 0 in a short time/ten minutes/5 miles) so it would be interesting to see if it happens on other '13s.
I have a 2013 for the next week or so but no ELM nor any android devices..

That's okay, it may have been fixed with v.k which I just dl today.
 
barsad22 said:
And what is the Health number (all I can find is a "16-bit number I'm playing with" earlier in this thread)?
Again, sorry if I missed it in earlier posts.

JG

I'm interested in the same thing right now as well. I recently updated to the latest version, and have been unnerved by the "health" figure ever since I first saw it. Mine's lingering around the 68% area, apparently dropping. I believe it started at around 72% or so when I first discovered it a few weeks ago. I've since started changing driving habits a bit, and it seems to have stopped the downward trend, now fluctuating around this (last night while charging):

2013-08-19 01.00.23.png

An explanation I've read is that health represents the battery's internal resistance - but not much to explain what that represents. The internal resistance is how much the voltage drops under load - how much effort the battery has to put forth to deliver the amount of power being consumed. This is what makes or breaks a battery, and why lithium has such a huge advantage over lead and earlier batteries: it has a very low internal resistance. As this resistance rises, health gets lower. I'd imagine the Leaf's computer uses this information to protect the battery as much as it can, by setting limits as needed regarding regen and acceleration.

In other words, health is actually very important. This explanation of internal resistance goes in line with all the trends I'd seen in posts I've read so far, and my own car's experience. It could spell an early decay for a strained battery. It seems very much dependent on how much strain is put on the battery during its use. Some folks are posting pretty decent health, and low health seems somewhat rare. I've driven the past 9 months of my Leaf like a racecar for the most part - but with zero quick-chargers to abuse in my area. Just over a thousand L2 charges, three quick charges. It's also a 2011 model that sat unused on a lot for over a year. The sudden racecar abuse of a battery that sat for a year might not be the best thing in the world...

The big question I've got now is... what can be done to improve health, not just stop killing it?
 
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