EV Battery Degradation Comparison Tool

[marspilgrim]

From the GeoTab Blog

https://storage.googleapis.com/geotab-sandbox/ev-battery-degradation/index.html

 

[paulgipe]

From the GeoTab Blog

https://storage.googleapis.com/geotab-sandbox/ev-battery-degradation/index.html

Whoa, did you create that? Where did you get your data?

I am tracking our Bolts SOH if you need our data.

Paul

 

[marspilgrim]

Nope, it is just a blog that is part of a fleet owners website. I assume the data is aggregated from the all the companies tracking their vehicles. I mean, probably take it with a grain of salt but it was interesting selecting the different cars to compare. the Bolt is a little to new and fewer of them on the road to have enough data points. We'll know more in ten years.

 

[SparkE]

Well, maybe they take amazing care of their vehicles. But looking at the line for 2012 and 2013 LEAFs, that degradation looks like complete ********.

 

[michaelbolt]

The curves are not plausible. Until whoever created that shows where their data came from, it should be ignored.

 

[mechanic]

What program can measure SOH (or kWh) high-voltage battery?

 

[mechanic]

Car Scanner.

 

[desiv]

But looking at the line for 2012 and 2013 LEAFs, that degradation looks like complete ********.

Not necessarily...
We know some Leafs in hot climates had really bad degradation. But that wasn't the case in other areas with cooler climates and places that were L2 heavy without a lot of Chademo.
If this data doesn't include those hot climate Leafs (i.e. is a lot of European Leafs, etc..), it might not be too far off...

That's the thing about data. It can be accurate, and still not useful depending on what the collection method and scope is.. ;-)

 

[mechanic]

I asked about a program that can show the capacity of a high voltage battery.

 

[SparkE]

But looking at the line for 2012 and 2013 LEAFs, that degradation looks like complete ********.

Not necessarily...
We know some Leafs in hot climates had really bad degradation. But that wasn't the case in other areas with cooler climates and places that were L2 heavy without a lot of Chademo.
If this data doesn't include those hot climate Leafs (i.e. is a lot of European Leafs, etc..), it might not be too far off...

That's the thing about data. It can be accurate, and still not useful depending on what the collection method and scope is.. ;-)

1) the degradation for a 2013 LEAF is a straight line down to 80% after 6+ years. That's BS.

2) If the data set is small or restricted to "certain climes", it isn't very useful. Again, pretty much BS. Not necessarily *untrue*, just useless. Data on ONE 2013 LEAF driven in Portland OR is useless to just about everybody. GIGO.

 

[desiv]

2) If the data set is small or restricted to "certain climes", it isn't very useful. Again, pretty much BS. Not necessarily *untrue*, just useless. Data on ONE 2013 LEAF driven in Portland OR is useless to just about everybody. GIGO.

Yep, that's my point, although the it isn't necessarily useless (and I see you said to "just about everybody" so you aren't saying that...).

We'd need to know more about what that information was looking to show...
If it was looking at a "How would batteries perform assuming we remove heat/QC as a variable" then it might still be valid for that exercise.
(Although I can see a lot of reasons that is also problematic, so probably not.. ;-)

My point is just that studies can be flawed, or they can just be taken out of context...
That isn't necessarily the fault of the study, but the person misunderstanding it's focus...

My Leaf, even in Oregon, had more degradation than that. But I was QC'ing multiple times a day.
Yeah, I know.. I had a 120 mile round trip commute. And no L2 at work. So initially I would QC when I got to work.
As it dropped after the first year, in the Winter, I would also have to QC on the way to work and on the way home. Initially, just 5 or 10 minutes (on the way to work, it was nice because I would QC at a place that had a Gas station/mini-mart and I'd get my hot chocolate too). So that was 3 QCs a day. Over the next two years, my mid drive QCs were closer to 20 minutes.
But, as I was using the West Coast Electric Highway ($20/month unlimited) and I could get some work/reading done while QC'ing, it was still fine (and the car was paying for itself that way).

That said, my wife made me agree that when an EV we could afford and I liked came out that could make the commute without having to QC, I'd move to that... And so after 3+ years with the Leaf (which I liked and saved me a lot of money), I moved to the Bolt, which I also really like (although doesn't save me as much money, but lots of time). ;-)

Sorry, that was a bit off topic ramble..
Anyway, studies and data are great, but we all need to understand them in context.
It's the DIKW concept.
Data -> Information -> Knowledge -> Wisdom.

The above stats are probably just data (although they could be Information depending??), but by themselves they aren't knowledge or wisdom. ;-)