Sudden drop in battery health

[DJ Palmis]

After 3 years and 40k kms, my battery had a really bad battery degradation.
By "bad" I mean: Battery degradation was quite constant, but suddenly it raised with no reason.
My projected rang is 460 km right now.
Any comment?
I always tried to keep my battery at the best as possible..
Opening a ticket would be useless..

 

[jjrandorin]

This looks like you are saying a drop from approximately 72kWh usable to 69kWh usable is "really bad degradation". Is that what you are saying?

 

[DJ Palmis]

This looks like you are saying a drop from approximately 72kWh usable to 69kWh usable is "really bad degradation". Is that what you are saying?

Slightly different: why the drop is so fast and why now? And, by interpolation, it doesn't seem to stop..

And BTW: when new it was 74.5 kWh

 

[jjrandorin]

Slightly different: why the drop is so fast and why now? And, by interpolation, it doesn't seem to stop..

And BTW: when new it was 74.5 kWh

I was looking at the chart you posted., with the only thing that looks like a "drop" to me. On the chart, it looks like its about 73kWh and at the bottom of the line, its around 69kWh. Is that not what that chart says? What it was new isnt relevant to your question on "large drop".

Im simply asking if what you are considering a Large drop, is a drop from 73kWh to 69kWh.

isnt that in the realm of numbers where it could be BMS adjustment?

 

[LoudMusic]

Interesting chart. I'm curious how it will look in another 5kkm.

 

[GtiMart]

Have you changed your charging behavior around the time the chart direction changes? Maybe you've stopped letting the SOC go low, or stopped charging high, and the BMS cannot calculate capacity as well? Maybe you've installed a software update that changed the way the BMS calculates capacity? You had another drop in the 10-15k range, was there a reason for it?

It might not be an actual change in your battery capacity, it might just be a reporting change. You can see that sometimes it recovers too...

 

[DJ Palmis]

Interesting chart. I'm curious how it will look in another 5kkm.

Honestly me too..

Have you changed your charging behavior around the time the chart direction changes?

If you look at 37k km the estimated capacity was rising. In those days, for about 4 weekends I DC charged in the range 30-92%.
Then I charged at home (2kW) after months at 11kW.
As soon as I started charging at home started the drop.
So: (maybe too much) DC charging and then very slow charging.

Maybe you've stopped letting the SOC go low, or stopped charging high, and the BMS cannot calculate capacity as well?

I charged from 7% to 100% but it did not helped: 467 km was the projected range. Still falling.

Maybe you've installed a software update that changed the way the BMS calculates capacity?

sadly not: the drop started within the same update..
But I had a problem (DIR_a126 "Power reduced" and DIR_a103 "Power limited" on the car, urgent enough for immediate visit, or wait until scheduled appointment?) and the remote support told me that I did not reset since many days. The soft and hard reset fixed the issue (I hope).
So maybe there was something wrong in the car algorithms.

You had another drop in the 10-15k range, was there a reason for it?

If I remember correctly it was due to covid lockdown. I used the car for few days.

On the chart, it looks like its about 73kWh and at the bottom of the line, its around 69kWh. Is that not what that chart says? What it was new isnt relevant to your question on "large drop".

Your right on both affirmations.

isnt that in the realm of numbers where it could be BMS adjustment?

Yes it can be.

 

[johnny_cakes]

7% degradation after 3 years isn't bad. I bet that puts you in the top 50 percentile.

 

[DJ Palmis]

sadly not: the drop started within the same update..
But I had a problem (DIR_a126 "Power reduced" and DIR_a103 "Power limited" on the car, urgent enough for immediate visit, or wait until scheduled appointment?) and the remote support told me that I did not reset since many days. The soft and hard reset fixed the issue (I hope).

After vacation (and 900km) they changed the superbottle.
I feel that the projected range drop is related to the superbottle issue.
I think battery conditioning affected the projected range and they are not fixing the consequences.
Hope I'm wrong.