lorenfb
Posts: 2272
Joined: Tue Dec 17, 2013 10:53 pm
Delivery Date: 22 Nov 2013
Leaf Number: 416635
Location: SoCal

Re: My 2016 30KWh experiencee

Wed Jul 18, 2018 6:48 pm

dwl wrote: As a battery degrades the Ah capacity reduces and conductance in ohms rises.
No!

Please re-read what was posted. Conductance is the inverse of resistance and is measured is mhos and NOT in ohms!
Many have thought over the years that Hx was the internal resistance of the battery in ohms/milliohms. After analyzing
how it changes over time, i.e. it decreases, it's obviously NOT simply the internal resistance or conductance of the battery.
Furthermore, since its value doesn't change as the battery temperature changes, it's not some absolute value. And since
its value takes the form of a ratio/percentage like SOH, one can most likely conclude that it's the ratio of the present battery
conductance to the original battery conductance providing a similar battery health measurement as does SOH. Yes, you're
correct in that until recently, it hadn't been clearly defined on the MNL forum. If you have knowledge otherwise, then
present it.

Please review my battery data. The battery resistance increases as the battery degrades. So that implies that the battery
conductance decreases. Don't confuse the two.

Additional info here; http://mynissanleaf.com/viewtopic.php?f ... &start=130
Last edited by lorenfb on Wed Jul 18, 2018 9:08 pm, edited 1 time in total.
#1 Leaf SL MY 9/13: 74K miles, 48 Ahrs, 5.2 miles/kWh (average), Hx=70, SOH=78, L2 - 100% > 1000, temp < 95F, (DOD) > 20 Ahrs
#2 Leaf SL MY 12/18: 4.5K miles, 115 Ahrs, 5.5 miles/kWh (average), Hx=98, SOH=99, DOD > 20%, temp < 105F

webeleafowners
Posts: 908
Joined: Mon Oct 05, 2015 5:37 pm
Delivery Date: 06 Oct 2015
Location: Okanagan Valley British Columbia

Re: My 2016 30KWh experiencee

Wed Jul 18, 2018 7:43 pm

We don't have leaf spy. We had little degradation on our battery before the update based on our very predictable repeating driving patterns. Hard to put it in percentages but maybe 12 to 16 KM depending on the time of year. Since the update we seem to have it all back although its hard to put a number on it. Because of our driving patterns and speeds the GOM is very accurate to what we actually get. When we got the car 200 KM was easily achievable for real world range under our driving conditions and speeds. It dropped off to the mid 180s over the last couple years. Now its back over or around 200km. We also get more regeneration bubbles when the battery is at 95 percent (3 or 4) compared to 90 percent before we got 4 regen bubbles before the update. For us we think the update made a difference.

I have no loyalty to any brand but credit where credit is due, our Nissan leaf has been flawless since we bought it and is simply the best car we have ever owned. Literally nothing has gone wrong and other than our 30 dollar per month auto car wash subscription it hasn't cost us a dime. Well that and a jug of washer fluid.
2015 Smart Electric Drive convertible.
2016 Nissan Leaf SV 30KWh
EV only Family...well except for the big diesel motorhome. :shock:

lorenfb
Posts: 2272
Joined: Tue Dec 17, 2013 10:53 pm
Delivery Date: 22 Nov 2013
Leaf Number: 416635
Location: SoCal

Re: My 2016 30KWh experiencee

Wed Jul 18, 2018 7:47 pm

webeleafowners wrote: I have no loyalty to any brand but credit where credit is due, our Nissan leaf has been flawless since we bought it and is simply the best car we have ever owned. Literally nothing has gone wrong and other than our 30 dollar per month auto car wash subscription it hasn't cost us a dime. Well that and a jug of washer fluid
Notwithstanding the Leaf's battery, most MNL forum members would agree.
#1 Leaf SL MY 9/13: 74K miles, 48 Ahrs, 5.2 miles/kWh (average), Hx=70, SOH=78, L2 - 100% > 1000, temp < 95F, (DOD) > 20 Ahrs
#2 Leaf SL MY 12/18: 4.5K miles, 115 Ahrs, 5.5 miles/kWh (average), Hx=98, SOH=99, DOD > 20%, temp < 105F

dwl
Posts: 107
Joined: Tue Jan 05, 2016 5:06 pm
Delivery Date: 08 Jan 2016
Leaf Number: 112097
Location: New Zealand

Re: My 2016 30KWh experiencee

Wed Jul 18, 2018 10:54 pm

lorenfb wrote:
dwl wrote: As a battery degrades the Ah capacity reduces and conductance in ohms rises.
No!

Please re-read what was posted. Conductance is the inverse of resistance and is measured is mhos and NOT in ohms!
Sorry, bit tired and was posting in a hurry, and meant to say resistance in ohms rises. It was confusing me when your data was reported as mohms - too many letters :?

If I take some sample data from your Leaf:
11/20/14 -13,700 miles, 76 mohms per LeafDD, 20 Deg, 73% SOC
11/27 -13,800 miles, 67 mohms per LeafDD, 25 deg, 63% SOC
4/2/18 - 62,000 miles, 110 mohms per LeafDD, 18 deg, 94% SOC
6/13/18 - 65,000 miles, 84 mohms per LeafDD, 26 deg, 52% SOC
This suggests the resistance has risen from around 0.07 ohms to about 0.1 ohms over 3.5 years.

If I look at the discharge data (which I would assume is easier to measure during use by the BMS) from https://avt.inl.gov/sites/default/files ... af9270.pdf over 2.5 years and under 24,000 miles it rises from about 0.11 ohms to 0.15 ohms. Higher than your readings but measurement methods will be different. A LeafDD report from these ANL Leafs would have been valuable.

So LeafDD reports as a resistance but Leaf Spy Hx is a percentage, reducing as resistance increases, of some arbitrary starting value?

This early post has me confused whether the reported 16 bit number is rising or falling as the battery ages: "Another 16 bit number also seemed to track capacity but was in the (initially observed) range of 7000 to 10200.. Taken as a percentage with two digits of precision I decided to call this "health" for lack of a better term. On the old software and especially for cars with only moderate capacity loss (still 12 bars) it seemed to track the Ah Capacity fairly close. Now that health is reported on LeafDD and the ELM battery app we've been able to track it over a much larger number of cars and seen some strange stuff.. like REALLY low numbers for cars with more capacity loss.. or 105-111% for some 2013 packs with Ah Capacity pegged at 67.3620Ah. What does it all mean? I don't know" - from http://www.mynissanleaf.com/viewtopic.p ... 29#p319129 Is this the same parameter?
2014 S - 6000 km Jan 2016; 45000 km May 2017 95% SoH; 68,000 km Mar 2018 90% SoH

lorenfb
Posts: 2272
Joined: Tue Dec 17, 2013 10:53 pm
Delivery Date: 22 Nov 2013
Leaf Number: 416635
Location: SoCal

Re: My 2016 30KWh experiencee

Thu Jul 19, 2018 1:07 am

Using my LeafDD data from the other thread:

11/14 @ 14K miles, 20 deg, resistance = .076, 63 Ahrs
6/18 @ 65K miles, 18 deg, resistance = .110, 50 Ahrs

Rr - resistance ratio (now / new) = .110 / .076 = 1.44 (144% - an increase)
Cr - conductance ratio (now / new - Hx) = 1 / Rr = .076 / .110 = .69 (69% - a decrease), my actual Hx now reads 70% (see below)

SOH = Ahrs (now) / Ahrs (new) = 50 / 63 = 79 %

Although SOH has decreased to a lesser extent than Hx, both track one another as the battery degrades.
#1 Leaf SL MY 9/13: 74K miles, 48 Ahrs, 5.2 miles/kWh (average), Hx=70, SOH=78, L2 - 100% > 1000, temp < 95F, (DOD) > 20 Ahrs
#2 Leaf SL MY 12/18: 4.5K miles, 115 Ahrs, 5.5 miles/kWh (average), Hx=98, SOH=99, DOD > 20%, temp < 105F

dwl
Posts: 107
Joined: Tue Jan 05, 2016 5:06 pm
Delivery Date: 08 Jan 2016
Leaf Number: 112097
Location: New Zealand

Re: My 2016 30KWh experiencee

Thu Jul 19, 2018 1:44 am

I now realise that the H parameter from LeafDD or Hx from Leaf Spy is a measurement from the BMS, which doesn't change with the update, while the resistance measurement seems to be computed in LeafDD:

"For software version 1.1.4 or newer (units shipped in July 2013) if you see two dots vertically near the bottom center of the main page that indicates an impedance test was done and results are waiting on page 2 (described below). The last line on Page 2 will be temporarily replaced with an impedance reading (mohms) as well as the pack SOC and temperature at the time of the test. This is basically an indication of how much the voltage sags under load (or rises on a DCQC or regen) and thus how much power you have. The Leaf battery has very low impedance with plenty of margin so this not so important as perhaps interesting. A new Leaf might be 50-60mohms whereas a degraded vehicle could be 2x that or more". http://www.mynissanleaf.com/viewtopic.php?t=12561

From the same page "H is a number in the group 1 data which looks like a Health % number but I'm not really sure. Expect about 100% on a new car. (I did see 111 on a new 2013 with 67.4Ah capacity, but under most other cases it seems to scale to the Ah capacity on most other cars)".
2014 S - 6000 km Jan 2016; 45000 km May 2017 95% SoH; 68,000 km Mar 2018 90% SoH

lorenfb
Posts: 2272
Joined: Tue Dec 17, 2013 10:53 pm
Delivery Date: 22 Nov 2013
Leaf Number: 416635
Location: SoCal

Re: My 2016 30KWh experiencee

Thu Jul 19, 2018 7:50 am

dwl wrote:I now realise that the H parameter from LeafDD or Hx from Leaf Spy is a measurement from the BMS, which doesn't change with the update,
And the reason is? You do acknowledge now that Hx (mine @ 70% per LeafDD) is also an indication of battery degradation
as is SOH (mine @ 78% per LeafSpy), right?
#1 Leaf SL MY 9/13: 74K miles, 48 Ahrs, 5.2 miles/kWh (average), Hx=70, SOH=78, L2 - 100% > 1000, temp < 95F, (DOD) > 20 Ahrs
#2 Leaf SL MY 12/18: 4.5K miles, 115 Ahrs, 5.5 miles/kWh (average), Hx=98, SOH=99, DOD > 20%, temp < 105F

dwl
Posts: 107
Joined: Tue Jan 05, 2016 5:06 pm
Delivery Date: 08 Jan 2016
Leaf Number: 112097
Location: New Zealand

Re: My 2016 30KWh experiencee

Thu Jul 19, 2018 1:05 pm

lorenfb wrote:
dwl wrote:I now realise that the H parameter from LeafDD or Hx from Leaf Spy is a measurement from the BMS, which doesn't change with the update,
And the reason is? You do acknowledge now that Hx (mine @ 70% per LeafDD) is also an indication of battery degradation as is SOH (mine @ 78% per LeafSpy), right?
The H measurement is mentioned separately in the LeafDD documentation. I read those notes as saying mohms is a calculation by LeafDD while H is extracted from the BMS. Sorry I don’t have LeafDD.

Your data is very interesting. Your mohms data bounces around a large amount, as may be expected for the type of analysis being done, while Hx is much more heavily weighted and smoothed. Is your 70% for LeafDD called H and also moves about less or is the 70% based on the one comparison of mohms data?

Unfortunately we lack much calibration of Hx to know whether it is really measuring the resistance by a similar method as LeafDD or whether it is some other factor that represents a loss of capacity that hasn’t been subject to calculation errors like we see for Ah/SoH.
2014 S - 6000 km Jan 2016; 45000 km May 2017 95% SoH; 68,000 km Mar 2018 90% SoH

lorenfb
Posts: 2272
Joined: Tue Dec 17, 2013 10:53 pm
Delivery Date: 22 Nov 2013
Leaf Number: 416635
Location: SoCal

Re: My 2016 30KWh experiencee

Thu Jul 19, 2018 6:26 pm

dwl wrote: Unfortunately we lack much calibration of Hx to know whether it is really measuring the resistance by a similar method as LeafDD or whether it is some other factor that represents a loss of capacity that hasn’t been subject to calculation errors like we see for Ah/SoH.
Why do you insist on making H/Hx more difficult than it really is? Both LeafSpy and LeafDD both read the same data (0xXX) from the BMS
and present it without any modifications/calculations. If you think the H/Hx represents something other than what has been noted,
then please compile data which would indicate otherwise. If you haven't, buy LeafSpy Pro and start analyzing your own data.

You do realize that battery resistance is a key variable with regard to degradation for ANY battery, right? So it's very likely that Nissan
wanted that parameter determined by the BMS over time AND presented as another measure of the relative state of the battery's
health/degradation. Obviously as is case for SOH (a relative present Ahrs to the new Ahrs), having a parameter, e.g. H/Hx, would
be useful, right?
dwl wrote:The H measurement is mentioned separately in the LeafDD documentation. I read those notes as saying mohms is a calculation by LeafDD while H is extracted from the BMS. Sorry I don’t have LeafDD.
Correct. A battery resistance determination is done by using the method; R (battery) = delta V ( a change in battery voltage) divided
by delta I (a change in battery current). Every time hard acceleration is done, LeafDD calculates the battery resistance (SIMPLE).
The same approach can be used with LeafSpy. That shouldn't be too difficult to understand, right?
dwl wrote:Your data is very interesting. Your mohms data bounces around a large amount, as may be expected for the type of analysis being done, while Hx is much more heavily weighted and smoothed.
That's not true! My time series battery resistance data doesn't "bounce around a large amount". You do realize that the battery resistance
has two independent variables, i.e. time and temperature, SOC has basically no effect, right?

11/20/14 -13,700 miles, 76 mohms per LeafDD, 20 Deg, 73% SOC
11/27 -13,800 miles, 67 mohms per LeafDD, 25 deg, 63% SOC
11/30 - 13,900 miles, 56 mohms per LeafDD, 27 deg, 71% SOC
12/2 - 14.100 miles, 55 mohms per LeafDD, 28 deg, 67% SOC
12/16 - 14,500 miles, 89 mohms per LeafDD, 15 deg, 93% SOC
12/27/14 - 14,800 miles, 103 mohms per LeafDD, 11 deg, 24% SOC
3/10 - 17,400 miles, 60 mohms per LeafDD, 30 deg, 73% SOC
3/14 - 17, 550 miles, 56 mohms per LeafDD, 32 deg, 47% SOC
4/14 - 19,100 miles, 59 mohms per LeafDD, 25 deg. 38% SOC
5/4 - 19,989 miles, 64 mohms per LeafDD, 24 deg. 48% SOC
5/15 - 20,400 miles, 73 mohms per LeafDD, 20 deg. 41% SOC
5/22 - 20,700 miles, 58 mohms per LeafDD, 28 deg. 50% SOC
12/10/15 - 28,000 miles, 90 mohms per LeafDD, 19 deg. 92% SOC
4/5 - 32,000 miles, 74 mohms per LeafDD, 24 deg, 55% SOC
5/16 - 33,700 miles,89 mohms per LeafDD, 22 deg, 47% SOC
5/16 - 33.700 miles, 58 mohms per LeafDD, 31 deg, 76% SOC
10/5 - 39,300 miles, 100 mohms per LeafDD, 22 deg, 50% SOC
10/6 - 39,400 miles, 61 mohms per LeafDD, 30 deg, 51% SOC
10/7 - 39,500 miles, 80 mohms per LeafDD, 25 deg, 56% SOC
10/15 - 40,000 miles, 71 mohms per LeafDD, 27 deg, 45% SOC
10/30 - 41,000 miles, 74 mohms per LeafDD, 23 deg, 66% SOC
12/26/16 - 43,000 miles, 110 mohms per LeafDD, 13 deg, 77% SOC
6/10/17 - 49,600 miles, 89 mohms per LeafDD, 19 deg, 70% SOC
4/2/18 - 62,000 miles, 110 mohms per LeafDD, 18 deg, 94% SOC
6/13/18 - 65,000 miles, 84 mohms per LeafDD, 26 deg, 52% SOC

Again, still waiting for your data gathering and analysis with regard to your interpretation of H/Hx. Have you bought the LeafSpy Pro app yet,
i.e. it's a great app? If you feel that additional data from LeafSpy would help you to analyze H/Hx, put a request to Jim (Turbo3). He's always
receptive to LeafSpy update ideas. The Telsa version of LeafSpy (TM-Spy) has a helpful mode for determining battery resistance.
#1 Leaf SL MY 9/13: 74K miles, 48 Ahrs, 5.2 miles/kWh (average), Hx=70, SOH=78, L2 - 100% > 1000, temp < 95F, (DOD) > 20 Ahrs
#2 Leaf SL MY 12/18: 4.5K miles, 115 Ahrs, 5.5 miles/kWh (average), Hx=98, SOH=99, DOD > 20%, temp < 105F

dwl
Posts: 107
Joined: Tue Jan 05, 2016 5:06 pm
Delivery Date: 08 Jan 2016
Leaf Number: 112097
Location: New Zealand

Re: My 2016 30KWh experiencee

Thu Jul 19, 2018 9:58 pm

lorenfb wrote:Why do you insist on making H/Hx more difficult than it really is? Both LeafSpy and LeafDD both read the same data (0xXX) from the BMS and present it without any modifications/calculations. If you think the H/Hx represents something other than what has been noted, then please compile data which would indicate otherwise. If you haven't, buy LeafSpy Pro and start analyzing your own data.
I agree H and Hx are read directly. Most people are saying they think it measures resistance but are not sure - you seem more certain. Over time resistance rises and the capacity drops. I don't have any evidence that says H/Hx is only a resistance measurement. You are tying it to the mohms calculation as evidence which is fine as a sample but nobody else I have found has done to this extent so this is limited evidence.

I have used Leaf Spy Pro since early 2016 and encourage others to buy this version. I don't have LeafDD. I see the Hx tracking down as the battery ages. Is it measuring resistance? I don't know.
lorenfb wrote:You do realize that battery resistance is a key variable with regard to degradation for ANY battery, right? So it's very likely that Nissan wanted that parameter determined by the BMS over time AND presented as another measure of the relative state of the battery's health/degradation. Obviously as is case for SOH (a relative present Ahrs to the new Ahrs), having a parameter, e.g. H/Hx, would
be useful, right?
I totally agree it would be useful. I am trying to confirm whether H/Hx is a reasonably accurate measure of resistance.
lorenfb wrote:Correct. A battery resistance determination is done by using the method; R (battery) = delta V ( a change in battery voltage) divided by delta I (a change in battery current). Every time hard acceleration is done, LeafDD calculates the battery resistance (SIMPLE).
The same approach can be used with LeafSpy. That shouldn't be too difficult to understand, right?
I have previously done the same calculations from Leaf Spy Pro logs and determined mohms. While it seemed related to Hx it was by no means a good correlation and Hx could have been a capacity indication as my battery has also been slowly losing capacity over the last 2.5 years.
lorenfb wrote:
dwl wrote:Your data is very interesting. Your mohms data bounces around a large amount, as may be expected for the type of analysis being done, while Hx is much more heavily weighted and smoothed.
lorenfb wrote:That's not true! My time series battery resistance data doesn't "bounce around a large amount". You do realize that the battery resistance has two independent variables, i.e. time and temperature, SOC has basically no effect, right?
Using some examples:
11/20/14 -13,700 miles, 76 mohms per LeafDD, 20 Deg, 73% SOC
11/27 -13,800 miles, 67 mohms per LeafDD, 25 deg, 63% SOC
11/30 - 13,900 miles, 56 mohms per LeafDD, 27 deg, 71% SOC
12/2 - 14.100 miles, 55 mohms per LeafDD, 28 deg, 67% SOC
A difference of around 30% for a temperature change of 8° - to me this is a large variation - which one should be used?

And this group over a few days:
10/5 - 39,300 miles, 100 mohms per LeafDD, 22 deg, 50% SOC
10/6 - 39,400 miles, 61 mohms per LeafDD, 30 deg, 51% SOC
10/7 - 39,500 miles, 80 mohms per LeafDD, 25 deg, 56% SOC
using the first and last that is 20% difference for 3°and 40% for 8° using first two - which is right?

I don't believe the resistance changes this much with temperature and hence used the term bounces around. The H/Hx is far more sluggish to change. I do appreciate you sharing this data as only LeafDD is providing this visibility outside the INL pulse resistance results (which incidentally do have strange answers at high and low SoC).
2014 S - 6000 km Jan 2016; 45000 km May 2017 95% SoH; 68,000 km Mar 2018 90% SoH

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