Requesting Hx values for all 40/62 kwh LEAFers

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DaveinOlyWA said:
Learjet said:
Build date 2/19, SL Plus

KMAIRQ3l.png

Holy moley! You win the prize for lowest Hx!

Now, we can say that lack of DC charging is why and yes, DC charging seems to be the easiest way to raise it up BUT, I have only DC'd for 4 mins in the past 6 months and mine is not going down.

What are your charging habits? I see you don't drive a whole lot? What is your average miles per day driven?

I bought the car 1 year ago...so it sat on the dealers lot for a year. I don't know how they kept it charged, but it only had 20 miles or so on it and it was 100% when I dropped in to look at it....no appointment. In one year I drove 9,300 miles.

The hx on my first leafspy view was 95.55% with less than a 1,000 miles on the car....I keep a file with all the screen shots...looks like it has steadily dropped to the number above.

I only DCQC once from 30% to 80%, otherwise I keep the car mostly between 20% and 80% charging at home with the Nissan EVSE on a 240 outlet. About every month or two I will fully charge to 100% for a longer road trip.

So are lower Hx number good? LOL
 
Learjet said:
So are lower Hx number good? LOL

It depends how you define it. With Leaf 1 it tracked decreasing SOH, and based on longitudinal impulse battery resistance data it represented battery conductance.
 
Learjet said:
DaveinOlyWA said:
Learjet said:
Build date 2/19, SL Plus

KMAIRQ3l.png

Holy moley! You win the prize for lowest Hx!

Now, we can say that lack of DC charging is why and yes, DC charging seems to be the easiest way to raise it up BUT, I have only DC'd for 4 mins in the past 6 months and mine is not going down.

What are your charging habits? I see you don't drive a whole lot? What is your average miles per day driven?

I bought the car 1 year ago...so it sat on the dealers lot for a year. I don't know how they kept it charged, but it only had 20 miles or so on it and it was 100% when I dropped in to look at it....no appointment. In one year I drove 9,300 miles.

The hx on my first leafspy view was 95.55% with less than a 1,000 miles on the car....I keep a file with all the screen shots...looks like it has steadily dropped to the number above.

I only DCQC once from 30% to 80%, otherwise I keep the car mostly between 20% and 80% charging at home with the Nissan EVSE on a 240 outlet. About every month or two I will fully charge to 100% for a longer road trip.

So are lower Hx number good?
LOL

Have no idea. Unlike the Gen One's, the Hx is reacting completely different. The time on the dealer lot is interesting along with at least some time just sitting at 100%. Wish we knew whether your visit was coincidental or they simply kept it topped off after every test drive?

Like anything, its looking like we simply have to keep tracking yours and see where its at next year?
 
Had an interesting experience today. During my second efficienct test, the car decided it was bms adjustment time, and moved the SoH down while driving (.16%). This caused my Leafspy trip log to reflect a higher gid difference, though show same efficiency as my prior run on the dash.

Aero covers on now for my EV01+ wheels.

https://drive.google.com/file/d/10XaT8JJTaNaZOiVFxTObEOejfFR8M2wP/view?usp=drivesdk
 
DougWantsALeaf said:
Pretty good SoH. Do you DC charge at all? Astros are you in Texas?

We DC charge only on trips, but then we need 2-4 in a day. The Plus is *much* better than our previous Leafs for that, but we still can get up into the red and ~129F by the end of the day. We live in Seattle, and take most of our trips down to Oregon, with the longest trips being down to Ashland. Most of the miles are from commuting, and once the SoC gets down to mid 30% we plug in and charge to 100%. We typically plug in about twice a week.
 
I had a 35 mile drive at ~55 mph, and starting with a battery temp of 69F (just finished a l2 charge and car was garaged). Temps were 35F ambient. During the drive battery temps reduced 2F from the hottest sensor. Not amazing cooling, but with a 35F temp differential, there was measursble cooling. This is where the lower energy draw helps a bit in how far you can get reasonably in a day.

Iowa has multiple 200amp DC Chademo chargers available now across the state, so have been trying with the idea of trying a 1000km drive. 3 stops on a 35-40F day to see if I could do 3 back to back stops. The question is what speed to drive to minimize end to end time.

In heat of summer (90F), I doubt I would get even 2 full stops (to 75%) if battery started at 80F. I think in summer, you would need to alternate L2 and DC charging stops.
 
DougWantsALeaf said:
I had a 35 mile drive at ~55 mph, and starting with a battery temp of 69F (just finished a l2 charge and car was garaged). Temps were 35F ambient. During the drive battery temps reduced 2F from the hottest sensor. Not amazing cooling, but with a 35F temp differential, there was measursble cooling. This is where the lower energy draw helps a bit in how far you can get reasonably in a day.

Iowa has multiple 200amp DC Chademo chargers available now across the state, so have been trying with the idea of trying a 1000km drive. 3 stops on a 35-40F day to see if I could do 3 back to back stops. The question is what speed to drive to minimize end to end time.

In heat of summer (90F), I doubt I would get even 2 full stops (to 75%) if battery started at 80F. I think in summer, you would need to alternate L2 and DC charging stops.

I think it really depends on how the stops incorporate in your schedule. The obvious thing to do is plug in around 10% and charge to 70%. I did this but didn't charge past 65% and saw rapidgate at 105ishº but it was around 60 KW on what would would have been around 73-74 KW so slower? yes. Rapidgate like 40 kwh? :lol:
 
Thread resurrection for the sole purpose to see if there's a better understanding of HX on the 2nd Gen Leaf since this thread went cold 3 years ago?

I'm mostly curious because after a few months of ownership of a used 2018 40kwh, I can't find any negative symptoms from what appears to be a low HX. (~62)
The range, the LeafSpy SOH (88.68), the voltage delta at high/low SOC.... It all seems great and the car behaves flawless.
Admittedly, I'm not on high-speed interstates or freeways much, but I don't baby the car. I'm usually in the fast lane and never in anyones way, if you know what I mean. :)
The only thing I am careful about is not charging/storing to 100%, nor running the car down below 30% if avoidable.

Anyways, just wondering if there was more discovered regarding HX?
I know it was believed to represent resistance in the Gen1, and years of data must have corroborated that opinion. But from what I have found so far on the forum, early on in the Gen2 era apparently HX got turned on its ear.
 
Thread resurrection for the sole purpose to see if there's a better understanding of HX on the 2nd Gen Leaf since this thread went cold 3 years ago?

I'm mostly curious because after a few months of ownership of a used 2018 40kwh, I can't find any negative symptoms from what appears to be a low HX. (~62)
The range, the LeafSpy SOH (88.68), the voltage delta at high/low SOC.... It all seems great and the car behaves flawless.
Admittedly, I'm not on high-speed interstates or freeways much, but I don't baby the car. I'm usually in the fast lane and never in anyones way, if you know what I mean. :)
The only thing I am careful about is not charging/storing to 100%, nor running the car down below 30% if avoidable.

Anyways, just wondering if there was more discovered regarding HX?
I know it was believed to represent resistance in the Gen1, and years of data must have corroborated that opinion. But from what I have found so far on the forum, early on in the Gen2 era apparently HX got turned on its ear.
 
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Actually, Hx data complied over 2-3 years on Gen1 Leaf's indicate that HX represents battery conductance (inverse of resistance). Do a Forum search, you'll find supporting data. As the Gen 2 batteries age, the HX data may become meaningful, now Hx appears to be white noise.
 
Yes sir, I understand the Gen1 consensus on HX. I used the wrong terminology, apparently. :)

Was just curious if Gen2 HX was better understood, at this point. White noise is a fair enough way of saying it's NOT what it was with the Gen1.
 
There is probably no real consensus of what Hx is but after reviewing several LS shots of 40 kwh LEAFs, a pattern is emerging.

When Hx is low (around 100%), degradation rates are low.

When Hx is high (around 118-120%) degradation rates are high.

So I am looking for LEAFs that counter this observation.
You need to clarify definitions of "low" and "high" In my experience, Low Hx means higher rates of degradation while higher Hx means little or no degradation. In my case, I dropped to 91.3% SOH within 2 years but leveled off and now sit at 4 years 3 months at 91.72% SOH, Hx 114ish.

During adjustments, stats can go up (the ONLY time SOH/ahr can go up) and due to those numbers bouncing around every 3 months, I went TWO YEARS losing .07% SOH based on my anniversary dates.
 
You need to clarify definitions of "low" and "high" In my experience, Low Hx means higher rates of degradation while higher Hx means little or no degradation. In my case, I dropped to 91.3% SOH within 2 years but leveled off and now sit at 4 years 3 months at 91.72% SOH, Hx 114ish.

During adjustments, stats can go up (the ONLY time SOH/ahr can go up) and due to those numbers bouncing around every 3 months, I went TWO YEARS losing .07% SOH based on my anniversary dates.

Your correlation with SOH and HX is what prompted my original question.

My SOH is 88.68 and has barely dropped at all in the last ~6 months of near daily driving. (was 88.75 when purchased) Battery being near 6 years old.
Yet the HX is far lower than most I've seen posted. (~62ish)

I have yet to experience even a hint of a problem with the car's behavior. And the voltage delta between cells is good even with SOC in the low 30's/high 20's.
 
My 22' SV+ at around 8000 miles ( I'm retired, short trips, trickle charge only, one QC at the dealership two years ago)
SOH: 97.54
Hx: 97.99
Cell Balance: 15 mv
12v @13.04v
 
I'm reading the thread, should I be concerned about HX? The car is 10 months old and has 16,500 km
 

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I'm sure there will be someone who will disagree, but My take is you have nice even cell balance, nothing to indicate a problem, you can either "sell it now" and relieve your self of the anxiety, or enjoy the car, your choice. You can't change it, you can only change your outlook on it.
We have people who struggle to define exactly what Hx is measuring, I see no practical reason to stress out on some number when exactly what it is measuring isn't even well defined.
I'm sure someone will say "I'm not fit to burn" but that is my take on it.
 
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