The 40KWH Battery Topic

[LeftieBiker]

A little less snark would be appreciated. I decided after the last reading that 6 month intervals would be sufficient.

[DaveinOlyWA]

SOH rise is unique. I have seen a single "point" (.01%) rise during the day that negated itself by the next morning (only record data in morning or before first drive of the day)

As far as my loss, its settled into a pattern of a relatively large chunk lost every 90 days. Because of this rather predictable pattern, I have varied both charging and driving habits to see if anything affected this 90 day cycle and nothing has so far.

I am a few days to maybe a week to my next "adjustment" so we shall see what happens.

[DougWantsALeaf]

So the 40 KW battery is degrading at the same rate as earlier batteries?

[lorenfb]

So the 40 KW battery is degrading at the same rate as earlier batteries?

Really? And where're the data?

[DougWantsALeaf]

LorenB, it was a question.

Wanted to understand the rate of decline better.

[LeftieBiker]

So the 40 KW battery is degrading at the same rate as earlier batteries?

My conclusion, subject to change with more data, is that the 40kwh pack degrades much like the Wolf Pack (4/'13 - 2014): it doesn't degrade fast if kept cool but does if kept hot. It may be more sensitive to moderately high temps than the Wolf pack, which if true means that multiple QC sessions should be avoided in warm weather...

[jmurtagh13]

I was expecting a larger than normal reduction in SOH about now, but instead I got a .34% increase over the last 2 days.

No 100% charges in the last 6 months. Been charging to 65% once reaching about 20%. It has been hot here in Atlanta for the last few months.

I'll give the specifics if I can't get the images to show.







https://drive.google.com/file/d/18ZTVyH ... sp=sharing
https://drive.google.com/file/d/1kY6FMZ ... sp=sharing

[DaveinOlyWA]

I will add my car to the list of 2018's that have had battery stats go up (for the first time). I am now at a level that matches my stats from April 8th (a period when ahr went from 107.24 to 106.18 in 5 days) I am now at 107.01

So guessing BMS "overestimated my driving for April to July (which did happen slightly especially in June from 3 short vacations of 2-3 days and one medium one 7 days)

[jmurtagh13]

It will be interesting to see if this reversal continues to happen. Mine was pushed back to April 23rd.

My 3 month rolling loss not counting this last upward correction since Feb has dropped to .8% last year it was almost 2.5%

[SageBrush]

So the 40 KW battery is degrading at the same rate as earlier batteries?

My conclusion, subject to change with more data, is that the 40kwh pack degrades much like the Wolf Pack (4/'13 - 2014): it doesn't degrade fast if kept cool but does if kept hot. It may be more sensitive to moderately high temps than the Wolf pack, which if true means that multiple QC sessions should be avoided in warm weather...

My conclusion about the 'Wolf' pack is that the range of experiences is wide. It would not surprise me if the 40 kWh pack fairs similarly ... which would actually be good news since it is a bigger pack and carries a longer warranty than the 24 kWh LEAFs. I would not care to play the LEAF lottery with a new car purchase but it does suggest that informed purchase of a well behaving 40 kWh LEAF coming off lease would be reasonable for gentle use in non-hot climates.

This is my pampered 'Wolf' pack over the past 27 months, which I think fits in the well behaved group -- for LEAF, anyway.
The initial loss seen in the graph is actually the tail of a 10% loss in capacity after I bought the car, I presume part of a reset calibration.