mtndrew1
Posts: 296
Joined: Thu Oct 16, 2014 3:06 pm
Location: Los Angeles, CA

Re: Battery Ageing Model

Wed Apr 20, 2016 11:29 am

When I commented on MNL about the AVTA Volts holding up very well over very long periods and high mileages (>100,000 miles) you replied that the cars were rarely plugged in and driven on EV and this is the reason for the lack of pack degradation. Age and ambient temps were not a factor in your rebuttal.

Does time degradation not affect Volts? It seems that when Leafs are degrading quickly it's because of time and ambient temperature averages, not miles. When Souls are degrading slower than Leafs it's because the packs haven't had as much time under their belts and total mileage is dismissed. When Volts don't degrade it's because...they haven't had enough EV miles even though the packs are as old or older than the Leafs' and exposed to the same high Phoenix temps.

Just reading your posts it often seems as though you're making a concerted effort to twist data to show that TMS systems are entirely useless at slowing degradation and there's absolutely no way that Leafs degrade any faster than competing vehicles with thermal management. Perhaps I'm merely misunderstanding your intentions but it sure comes across that way to me through text. Naturally it can be difficult to understand someone's point through Internet forums.

I find it hard to believe that hundreds of engineers at these automakers have developed systems to slow degradation and all of their efforts are for naught, that they're missing something extremely elementary. GM warrants Volt packs against degradation with a stronger warranty than Nissan, as does Kia, yet I've never heard of a Volt pack being replaced for degradation (of course the Kias are still too young). There are many hundreds of Leaf packs that have been replaced for degradation under the class-action lawsuit warranty in some relatively mild climates (San Diego comes to mind).

Why is it that Chevrolet and Kia can guarantee their packs at no greater than 30% degradation for ten years or 100,000 miles yet Nissan had to be sued into guaranteeing no more than 33.5% over five years or 60,000 miles, and even then so very many Leafs have had their packs swapped?

As a consumer I would (and did) prefer thermal management backed up by a guarantee in writing. I don't see any evidence so far that these systems fail to slow degradation as compared to their passively managed competitors.

That said, I find the data points interesting and am looking forward to seeing how these AVTA charts progress over time and mileage regardless of whether or not the information supports the validation of TMS effectiveness.

edatoakrun
Posts: 6
Joined: Tue Apr 19, 2016 11:32 am

Re: Battery Ageing Model

Thu Apr 21, 2016 9:41 am

You clearly have a lot off off-topic issues to deal with, "mtndrew1".

On-topic:

mtndrew1 wrote:...Why is it that Chevrolet and Kia can guarantee their packs at no greater than 30% degradation for ten years or 100,000 miles...

As a consumer I would (and did) prefer thermal management backed up by a guarantee in writing...

Are either the Spark or Soul BEVs even offered for sale at Arizona dealerships?

If not, maybe that's integral to Kia's and GM's plans for their BEVs to deal with high ambient temperatures...

From the preliminary AVTA data available today, it seems likely to me that most or all Soul EVs driven in a climate as hot or hotter than Phoenix would qualify for replacement long before 10 years or 100k miles are covered.

Depending of course, on how accurately Kia measures battery degradation for warrantee purposes.

I'd be surprised if the Spark did much better, as the increased degradation due to its tiny battery pack (requiring almost twice the cycles to cover the same miles) will probably more than offset GM's more intensive pack cooling system.

mtndrew1
Posts: 296
Joined: Thu Oct 16, 2014 3:06 pm
Location: Los Angeles, CA

Re: Battery Ageing Model

Thu Apr 21, 2016 9:54 am

On topic, why is it that you dismiss age and ambient temperature on Volt packs older than highly-degraded Leaf packs of similar age in the in the same environment? If these factors are so dominant, as you repeatedly claim across two forums, why doesn't it apply to these cars?

It all just reads as Nissan brand loyalty, apology, and devotion as opposed to objective review of what's happening with these cars in the field.

If Nissan's EVs in San Diego or Sacramento can't make it 50,000 miles without losing a third of their battery capacity requiring a $6,000 warranty repair, that sure seems like a design fail on Nissan's part. The most apparent design flaw seems to be a lack of TMS.

JejuSoul
Posts: 1394
Joined: Wed Jul 08, 2015 6:47 am
Location: Jeju
Contact: Website

Re: Battery Ageing Model

Sun Apr 24, 2016 6:26 pm

The worst case scenario data we have been looking at recently can be a bit depressing.
How about this to cheer us up.
17,000 Renault Zoe's all above 100% SOH after 3 years.

Image

Found this image at http://insideevs.com/renault-zoe-r240-b ... kwh-total/

it is copied from this really interesting video presentation.

https://youtu.be/N6sRWGjFx5w
The codes for using Torque Pro can be found by clicking the link in the website icon under my user name on the left.

2016Electric
Posts: 137
Joined: Thu Sep 17, 2015 4:05 am
Location: Toronto, Ontario

Re: Battery Ageing Model

Mon Apr 25, 2016 6:27 pm

JejuSoul wrote:The worst case scenario data we have been looking at recently can be a bit depressing.
How about this to cheer us up.
17,000 Renault Zoe's all above 100% SOH after 3 years.

Image

Found this image at http://insideevs.com/renault-zoe-r240-b ... kwh-total/

it is copied from this really interesting video presentation.

https://youtu.be/N6sRWGjFx5w



That IS great news.

BTW... with the lower kw/km energy being consumed due to the warmer weather lately, my GOM is now gradually starting to show greater range available for any given % state of charge. Now, my dash is showing around 15.3 kw/100km... I'd expect well over 155 km on the GOM but that's all I'm getting so far... last week.. same energy stat (15.3), but only 140-145 km on the GOM. This seems to confirm my theory that the GOM uses some time of long-running weighted average, well beyond the energy stats for the last few charges.

That's what I suspected and why I commented on another thread that a concern about reduced range stemming only from a single day's GOM reading is ill-conceived.
Another member commented that temperatures rose on a single day (from cooler weather).. the EV was charged and yet the GOM was showing an unexpectedly low figure.
This is EXACTLY my experience.. and now with more time, the GOM stats are improving.

Bottom line - the GOM is just that.. an educated guess. And if you suspect a problem with your battery, instead of spreading fear and doubt with no hard stats, have your darn battery tested by Kia and come back with actual SOH figures (until we figure out how to pull SOH ourselves!)

JejuSoul
Posts: 1394
Joined: Wed Jul 08, 2015 6:47 am
Location: Jeju
Contact: Website

Re: Battery Ageing Model

Tue Apr 26, 2016 12:11 am

mtndrew1 wrote:Why is it that Chevrolet and Kia can guarantee their packs at no greater than 30% degradation for ten years or 100,000 miles ...

If you watch the Renault Zoe video you will hear the battery engineer state that if you extrapolate the degradation trend forward then most of the cars will reach ten years life without needing to replace the battery. The Zoe has LG Chem batteries and a TMS much the same as the Soul EV. I think the reason Kia offers the guarantee is that they too have extrapolated a trend. (I wonder if anyone knows how the Zoe does in Spain and Portugal - both have had extremely hot summers recently). There is self collected data from Zoe drivers here - http://canze.fisch.lu/battery-health-status/

https://youtu.be/N6sRWGjFx5w
The codes for using Torque Pro can be found by clicking the link in the website icon under my user name on the left.

mtndrew1
Posts: 296
Joined: Thu Oct 16, 2014 3:06 pm
Location: Los Angeles, CA

Re: Battery Ageing Model

Tue Apr 26, 2016 10:56 am

How interesting that the Zoe uses LG Chem cells instead of the AESC ones in the Leaf and e-NV200, seeing as both automakers are part of the same parent company. I, too, would be interested in Zoe data from hot climates but the general trend looks promising for longevity.

mtndrew1
Posts: 296
Joined: Thu Oct 16, 2014 3:06 pm
Location: Los Angeles, CA

Re: Battery Ageing Model

Tue Apr 26, 2016 11:01 am

2016Electric wrote:
Bottom line - the GOM is just that.. an educated guess. And if you suspect a problem with your battery, instead of spreading fear and doubt with no hard stats, have your darn battery tested by Kia and come back with actual SOH figures (until we figure out how to pull SOH ourselves!)


If we're talking about the same user, I really wish they had watched their ending SOC % at the end of their commute since day 1 to get a feel for actual degradation as opposed to GOM readout.

While my GOM has fluctuated wildly over the last year and a half (trending down dramatically), the SOC percentage consumed during my extremely consistent commute has remained the same over 24,000 miles, implying minimal degradation over that time. I'll have a battery test run at 45,000 miles when I turn the car in just for curiosity's sake. At this rate I'm guessing I'll have less than 15% degradation at that point.

2016Electric
Posts: 137
Joined: Thu Sep 17, 2015 4:05 am
Location: Toronto, Ontario

Re: Battery Ageing Model

Wed Apr 27, 2016 7:26 pm

Hey all:

Per Jeju's request and now having the revised OBC entries in torque, here are some additional stats on my vehicle that may be helpful...

Vehicle: 2016 Kia Soul EV (Luxury model with Chademo option), in service as of October 2015

KM total: As of this evening, 8,192 KM

Cumulative kWh CEC: 2,117

Cumulative kWh CED: 2,056

Battery deterioration: Best cell #15, with 0.0% (min det), Worst cell #77, with 3.5% (max det)

Climate: Toronto, Ontario (crappy, need I say more??).. lowest temp was Feb (if I recall correctly, -25C). Highest temp so far +25C last fall and maybe close to that a day or two a few weeks ago. Today was +7C to +10C or so. The vehicle is stored in an underground style parking garage, that usually does not fall below -5C.

Driving style: Mix of highway (100km/hr) and city (50-60 km/hr, in theory!) Trip meter tends to show around 36 km/hr avg. with Toronto traffic when driving just around town with no highway). The vehicle tends to get used during the week as a daily commuter, maybe 20-30 km per day max, at slower city speeds. On weekends, more highway around 80-100 km/hr, trips one way around 30-60 km average. At present, the dash is showing energy use of 15.3 kW/100km. Worst reading was highway use at -25C, lots of wind, and with snow tires mounted. I was pulling around 22 kW/100km that trip easily. Cabin was set to 22C. I might add.. aside from diminished range in the very cold temps, the car performed beautifully - perfectly smooth, quiet, and toasty warm. Average winter energy use was 18-20 kW/100km, mix of city/highway, and cabin set at 22C. I tried to use cabin pre-heat whenever possible (departing from home only, of course).

Charging behaviour: I use delayed charging almost exclusively, to charge the car beginning at 2am, set to 80%. This gives more than enough range during weekday commutes, even in the coldest months. Car probably stops charging usually within 2 hrs (so by 4 am), for the 7am morning commute. On weekends and when I know that I will be driving further, I charge to 100%, but try to plan whenever possible to reach a full charge shortly prior to departure (the timer works well for this).
The vehicle is charged at home, with 2 of three phases (commercial service) for a voltage that hovers between 208 and 2011 volts on average. The charger I built myself (OPENEVSE), which is set at 30 amps. During charging, the OPENEVSE reads 29.3 amp draw on its display when set at 30 (usually), which works out to 210x29.3=6.153kw. The reading I took this evening with the revised OBC codes showed 210.2 volts @ 28.7A and 6.0KW (so pretty close to my calcs).
I should add, in the winter I'd often plug the car in every night to take advantage of morning pre-heating, so SOC usually never fell below 55-60%, or went above 80%. Now that it's warmer, I push it a little more and don't feel compelled to charge every night. Still, I usually don't let the battery fall too low. Lowest ever was maybe 15%-19% or so.

Chademo:
I have used this maybe 3 or 4 times (unfortunately - I wish I had more opportunity to use this), mostly just to try it out. There are almost ZERO fast chargers around here.. and the greater Toronto area is home to around 6 million people. Truly, truly sad state of charing infrastructure at the moment here.. but I digress. Point being, not much fast charging on this battery pack, so far.


Wow.. that was MUCH more than I planned to write.

JejuSoul
Posts: 1394
Joined: Wed Jul 08, 2015 6:47 am
Location: Jeju
Contact: Website

Re: Battery Ageing Model

Wed Apr 27, 2016 9:18 pm

Thanks for the data. Your car is doing pretty much the same as everyone else. No usable capacity lost.
For example on 11th November 2015 my car was 6 months old.
I had driven 8000km. My deterioration was max 3.5% min 0.1%.
My energy counters were about 20% lower than yours though. Presumably that is the extra cost of heating the car in your cold winter.

If you could post the stats again in a few months or when there is a significant change it helps to average out the figures because any single reading isn't really reliable because of calibration and seasonal factors.

We don't have any climate related effect yet in the data we have been collecting. My car's 6 months of summer heat has degraded the same as yours in 6 months of winter cold. If you read the Phoenix AVTA discussion above it makes it sound that heat will make a massive difference really quickly. Most of the cars we have data for are from cooler climates (Norway, Sweden, Canada). It would be great if someone from a warmer climate could post some data here ( hint ... mtnandrew1 ... hint!)
The codes for using Torque Pro can be found by clicking the link in the website icon under my user name on the left.

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