Relationship between SOH and Hx in Leaf Spy?

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EVinCbus

Member
Joined
Apr 28, 2016
Messages
6
After several weeks of research on the Nissan Leaf and using Leaf Spy to test battery health on a few local used Leafs, I'm come across what I believe to be a good deal on a 2012 SL, 12 capacity bars, 25k miles, for $9500 OTD. Car fax reveals it was a personal lease from Illinois.

Recently I've noticed many owners reporting SOH and Hx values that are fairly equal with each other. This is making me a bit suspicious of the battery health values of the aforementioned vehicle.

Leaf Spy Pro reveals the following data: SOC=90.4% , 226 GIDs, 17.5kWh, AHr=56.17, SOH=85%, Hx=71.79%, 393.33V 0.61A. Should the Hx value be much closer to the SOH value? If so, what does this reveal about the REAL state of health of the battery?

I test drove this particular car for three days with mostly city driving of 25-45mph, low to mid 70ºF outside air temp (basically ideal conditions for optimal battery performance) and the range was showing upper 80s range in normal mode and mid 90s range in eco upon a full charge.

Alternatively, I've looked into a 2013 SV, 14k miles, with both the LED/QC Port and Bose/Surround View packages, CarFax shows it was a "government" car in Georgia, all for $2k more than the '12 SL. AHr=59.08, SOH=90%, Hx=90.01%. Worth the extra money?

I'd attach screenshots of the Leaf Spy data, but I can't seem to figure it out here. Advice?

Thanks.
 
I can't really comment on the LEAF SPY question specifically, but the 2013's battery seems to be in better health overall (and if I'm reading this correctly, the 2012 is on the verge of losing the first charge bar...).

Anyway, another factor to consider is climate. There were some nice (optional) improvements made to the heater starting in the 2013 model year. Do you know if it has the hybrid heater (as opposed to the standard resistive heater)? It's far more efficient down to the teens, and if you live somewhere where it gets cold this will be a big help in the winter. Also, I think the package that adds this also adds the 6.6kW charger, but someone would have to verify that.

Unless you can't swing the extra $2k, I'd definitely go with the 2013 if it had those extra packages. The 2013 battery I think has also held up a bit better than the 2012, but that is somewhat debatable I think.
 
Personally I'd get the '13, the '13 has features not found on the '12 including more efficient heater, dash SOC% display, ability to turn off the heater while still using the climate control, 1/2 the charge time if using a 30a EVSE, etc. The battery is also better on the '13. I guess the interior is a personal preference but I don't much care for the very light(read shows everything) interior of the '12, although being a SL the '12 may have a few options not on the '13SV. If you were talking $4k difference I might look more at the '12 but for a $2k difference(even if the '13 was from GA and not a cooler climate like IL) I'd get the '13.
Oh I forgot to mention the regen, if you like regen(the ability to drive almost without using the brakes) it's another big advantage with the '13. Actually regen is my biggest complaint I can't fix on my '12 to make it more like my '13, you can purchase a switch to shut off the heater and and use LeafSpy for a SOC% but nothing you can really do about slower charger, light interior or less efficient heater.
 
The '13 SV definitely has the heat pump/resistance heater combo. From what I understand, below a certain temp (I've read 26ºF and 32ºF), the resistance kicks in and it's no more efficient than the '12's resistance heater. Above that temp, I'm wondering if anyone has experience with keeping warm on a 12 mile commute, one way, using the seat and steering wheel heaters?

The 6.6kW onboard charger would be a nice upgrade, but I wonder if it's going to be worth the extra cost given this car will be used as the primary car for a teacher (no summer commuting or being parked in a sun-soaked parking lot during the hottest part of the year) who has a 24 mile roundtrip commute (10 highway miles). My wife and I would also use this car for weekly errands to the grocery store and whatnot (all well within a 10 mile radius). I see the modified L1 charger, or a home L2 charger, being more than capable of handling the task of home charging.

My wife had an old Saturn Ion with a light cloth interior and we hated it due to staining (all in the seat fabric really; the plastics clean up well). Now we both have black interiors---doesn't show the dirt like the light gray, but man does it get hot in the summer! Pros and cons to each I suppose, but we do have a child loves to put her feet/shoes on the seats. We'll likely end up getting leather replacements from leatherseats.com or katzkin anyway.

The brake mode is nice. I just experienced that today returning the '13 to the dealer.

Will I see that big of a difference with the electrolyte-enhanced battery on the '13 in Columbus, OH? From what I've read, it's all about slowing battery degradation in hotter climates, like Arizona.

It may sound that I've already made up my mind, but I haven't. I'm just trying to decide which is the best value proposition. The big question for me is will I actually see the benefits of the extra $2k spent on the '13? I'm having doubts.
 
Thanks LeafMuranoDriver.

Any others have Leaf Spy data where the Hx value is a bit lower than the SOH? The Leaf Spy app creator states in the help section that the Hx value is not fully understood, but is somehow inversely related to the battery's internal resistance. What exactly does this mean? Is the battery more resistant to taking or holding a charge?
 
EVinCbus said:
Thanks LeafMuranoDriver.

Any others have Leaf Spy data where the Hx value is a bit lower than the SOH? The Leaf Spy app creator states in the help section that the Hx value is not fully understood, but is somehow inversely related to the battery's internal resistance. What exactly does this mean? Is the battery more resistant to taking or holding a charge?
Click to expand...
I believe that a battery's "internal resistance" refers to a simple way of electrically modeling the battery. That model is just a theoretical ideal voltage source, in series with a resistor: the "internal resistance". It accounts for the immediate change in battery terminal voltage when the load (or charging) current changes. (Of course, if you leave a given load current connected long enough, the battery voltage changes for the other obvious reason: it becomes discharged. But the internal resistance is concerned with modeling changes over timescales so short that the total state of charge doesn't change significantly). The simple, but spectacularly impractical, way of determining the resistance is to see how much current flows from the battery when it's shorted out; the internal resistance would be the open-circuit battery voltage divided by the measured short-circuit current. A much gentler way is to measure how much the battery's terminal voltage changes as a result of applying a known (perhaps by measuring it also) current load.

One battery having a higher internal resistance than another will dissipate more energy as heat at any given current level, so it's kind of a way of describing the energy efficiency of a battery. And, to the extent that various chemical/physical degradation processes in the battery are thought to affect the internal resistance, it's reasonable to regard a modeled internal resistance as an overall figure of merit. I have heard some folks point out that Li-ion batteries don't lend themselves perfectly to this simplistic modeling, so it's unwise to expect that the internal resistance tells you absolutely everything you need to know about one, though.
 
The Hx has always been lower than the SOH on my 2013SV. I would recommend getting the 2013 over the 2012, especially if it was manufactured 4/13 or later.
 
I guess if the faster charging of the '13 doesn't really matter and your OK with the lighter interior and your OK with the much less motor breaking(regen) maybe the $2k saved might be worth it to you. Although I think you'll find the heater on the '12 will REALLY effect your range, like going from 60 miles range to 40 with much heat use. Even with my '13S which lacks the heatpump but still allows one to turn the heat off while still defogging, etc. the range isn't effected nearly as much as my '12. I did recently install the switch mod(easy to do, cost ~$25) and that allows me to run the air without also the heat but when I do kick the heat in my '12 it really drops the range, not as much with my '13. I believe the '12 heater is a fair amount less efficient than even a '13S with the resistive only heater, at least it seems that way to me. I'd love to have a heatpump but didn't know any difference at the time and the dealer was also clueless.
It's up to you and again for $4k difference I might look at the '12 but for only $2k.....well again it's up to you :)
 
jjeff said:
I guess if the faster charging of the '13 doesn't really matter and your OK with the lighter interior and your OK with the much less motor breaking(regen) maybe the $2k saved might be worth it to you. Although I think you'll find the heater on the '12 will REALLY effect your range, like going from 60 miles range to 40 with much heat use. Even with my '13S which lacks the heatpump but still allows one to turn the heat off while still defogging, etc. the range isn't effected nearly as much as my '12. I did recently install the switch mod(easy to do, cost ~$25) and that allows me to run the air without also the heat but when I do kick the heat in my '12 it really drops the range, not as much with my '13. I believe the '12 heater is a fair amount less efficient than even a '13S with the resistive only heater, at least it seems that way to me. I'd love to have a heatpump but didn't know any difference at the time and the dealer was also clueless.
It's up to you and again for $4k difference I might look at the '12 but for only $2k.....well again it's up to you :)
Click to expand...

Yeah as I recall in the 2011-2012 some of the tube carrying heated fluid were not insulated, and exposed to the outside air. In 2013 and forward models, these parts were insulated. So everything else being equal, the heaters in 2013 model years are better if only for that reason. But the heatpump makes a huge difference in efficiency and will keep your range from degrading significantly in the winter time, as previously mentioned. I know in comparing my experiences with our 2012 and 2015, we've found the same to be true. Also, it combined with the faster charger avoids the situation where can can use more energy heating the cabin than you can pull from a level 2 EVSE; rare problem, but a good one to avoid in extreme cold.

The more I think about it the more I'd say go for the 2013 if you can. Also, the 2012 may be a bit overpriced based on some recent transaction prices.
 
EVinCbus said:
The '13 SV definitely has the heat pump/resistance heater combo. From what I understand, below a certain temp (I've read 26ºF and 32ºF), the resistance kicks in and it's no more efficient than the '12's resistance heater. Above that temp, I'm wondering if anyone has experience with keeping warm on a 12 mile commute, one way, using the seat and steering wheel heaters?

The 6.6kW onboard charger would be a nice upgrade, but I wonder if it's going to be worth the extra cost given this car will be used as the primary car for a teacher (no summer commuting or being parked in a sun-soaked parking lot during the hottest part of the year) who has a 24 mile roundtrip commute (10 highway miles). My wife and I would also use this car for weekly errands to the grocery store and whatnot (all well within a 10 mile radius). I see the modified L1 charger, or a home L2 charger, being more than capable of handling the task of home charging.

My wife had an old Saturn Ion with a light cloth interior and we hated it due to staining (all in the seat fabric really; the plastics clean up well). Now we both have black interiors---doesn't show the dirt like the light gray, but man does it get hot in the summer! Pros and cons to each I suppose, but we do have a child loves to put her feet/shoes on the seats. We'll likely end up getting leather replacements from leatherseats.com or katzkin anyway.

The brake mode is nice. I just experienced that today returning the '13 to the dealer.

Will I see that big of a difference with the electrolyte-enhanced battery on the '13 in Columbus, OH? From what I've read, it's all about slowing battery degradation in hotter climates, like Arizona.

It may sound that I've already made up my mind, but I haven't. I'm just trying to decide which is the best value proposition. The big question for me is will I actually see the benefits of the extra $2k spent on the '13? I'm having doubts.
Click to expand...

Regarding short commutes with only the heated steering wheels and seats: they'll help but on a cold day you'll need cabin heat unless you go to extremes like some people here do (would not recommend).

Also you'll need to consider defrost needs...
 
Thanks for all the feedback.

BoulderLeaf, I'm wondering why you believe the '12 is overpriced at $9500 out the door? The price of the car alone (minus tax, doc fee and registration) is really ~$8550. Add the dealers $250 doc fee, 7.5% sales tax in my county, and $32.25 for registration, and it comes out to a few bucks under $9500.

I've done a fairly broad search of a 250 mile radius for the same car and the few that are a couple hundred cheaper have more miles and have already lost 2 capacity bars (one was at 74%---close to losing it's third bar).

There are four local Nissan dealers that sell Leafs near me. One refuses to let me plug in the OBD2 dongle to read the health of the battery; I refuse to do business with them.

Anyway, I guess from the weeks I've spent searching and seeing what's out there, I thought $9500 including tax and all the fees seemed like a relative deal.
 
baustin said:
The Hx has always been lower than the SOH on my 2013SV. I would recommend getting the 2013 over the 2012, especially if it was manufactured 4/13 or later.
Click to expand...

I've seen the 4/13 in a few places. I have a MY2013, Built 04/17/13. I bought it used, on a moment's notice, because it seemed like a good deal, but it had 11 bars at 16000 miles. I worried a lot about whether I had the old battery or new battery at first.
I worry less, now, but I would like to know. Is there a way to tell, or has anyone established a date/VIN changeover?

2016-08-04 14:10:34, AHr=53.81 SOH=82% 382.63V SOC=67.0% Hx=77.58% 153 GIDs 54.4%
odo=18,250 miles 35QCs & 599 L1/L2s
 
I've seen the 4/13 in a few places. I have a MY2013, Built 04/17/13. I bought it used, on a moment's notice, because it seemed like a good deal, but it had 11 bars at 16000 miles. I worried a lot about whether I had the old battery or new battery at first.
I worry less, now, but I would like to know. Is there a way to tell, or has anyone established a date/VIN changeover?
Click to expand...

The change seems to have taken place beginning with the first car produced in April or 2013. Of course, there my be a few 'Canary Packs' that were slipped into early April cars - we don't know.
 
LeftieBiker said:
we don't know.
Click to expand...
Yep.

ClarD's reading isn't very good, IMHO, but it's also going to depend on how the car was treated and the climate where it resided.

Here's what my 5/2013 built used '13 Leaf SV w/no CHAdeMO reads as of a few minutes ago. I'm getting closer to losing a CB.

AHr: 57.16
SOH: 87%
Hx: 85.84%
odo: 37,630 mi
0 QCs & 2518 L1/L2s (I frequently use the charging timer, esp to just 80%, so it's known that the L1/L2 value can have extra increments due to the timer)

# of gids on a full charge is usually high 240s to very low 250s (like 251).
 
EVinCbus said:
The '13 SV definitely has the heat pump/resistance heater combo. From what I understand, below a certain temp (I've read 26ºF and 32ºF), the resistance kicks in and it's no more efficient than the '12's resistance heater. Above that temp, I'm wondering if anyone has experience with keeping warm on a 12 mile commute, one way, using the seat and steering wheel heaters?
Click to expand...
I know this is a very old post, but for what it's worth, it's getting into the 30*F temperature range here and I make my 40 mile commute keeping warm with the seat heater and steering wheel heater. Occasionally I kick on the cabin heat for a few minutes then shut it back off.
The heat pump only uses 600 watts, if the resistive heater turns on I've seen it go as high as 2350 watts (according to leafspy) the main factor seems to be how high you set the requested temperature and how could it currently is inside the cab. Even at 32* outside, once the cab is warmed up to 70* and my requested temperature is 72-75* the resistive heater will be anywhere from off to 300 watts and the heat pump at 600 watts.

My 2016 pack is
SOH =100%
Hx=94.82%
 
The resistance heater usually comes on at first even in milder temps, to help heat the air faster. The temp at which the heatpump becomes effectively useless (the actual temp at which it stops working is about 6F) is about 14F. Energy consumption jumps noticeably below 30F or so, then again below 24F or so, then again at about 14F.
 

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