Only 3% battery degradation on M3LR (E5D battery) after +3 years and 75.000 Km!

[KenBlub]

Yeah I think it's pretty clear from that thread what I think of the Battery Health Test, lol. It doesn't matter what it puts out, it's of no consequence and is entirely depending on what is chosen as the denominator. It's not even determinative of whether or not you have a warranty claim (it's likely not used for that purpose, plus I don't think a vehicle has ever reached the warranty claim threshold, or come close (certainly hasn't been a report here that I can recall), so it's kind of academic).

Just use the energy screen method or SMT.

As usual, have to be careful about using Full Pack When New (it's just a hard-coded value close to the starting capacity but doesn't necessarily represent an accurate starting capacity (it could be higher or lower than typical starting capacity). For this particular (LG?) pack, I think this was around the time they were locking out the Panasonic packs but not locking out these? Anyway someone would have to review the history to determine where typical vehicles actually started.

We don't have EPA tests to rely on AFAIK either, @AAKEE, because this particular vehicle's results were not released in the US. I think. I'm sure there is a test result but not public domain.

Seems like it was ballpark 75kWh as I recall (not the 74.5kWh FPWN hard-coded value). But there are SMT scans & pictures posted on this website from brand new cars matching this description, which could be looked up by those so-inclined. Just have to find the right thread (from around that time). Lots of captures.

The degradation threshold can be calculated too, by those so inclined. The method there is well established but you actually have to know what the true maximum displayed miles is (probably also in that old thread).

I seem to remember claims that LG NMC (this pack?) are slightly slower to lose capacity, presumably due to chemistry differences affecting the growth rate of SEI. But anyway 7.5% after a few years is pretty good.

I was playing around today with the energy screen to determine capacity of my 78.8 LR. I use the low SOC strategy and today the reading was at 16%. I really never charge above 35%. I know it’s better at a higher SOC. Here is what I did to get around the low SOC problem

I went to the trips screen. It tells me lifetime mileage and lifetime kWh used. Using my car I divided 6162/1473 and got 4.18. I then multiplied 4.18 x 78.8 for 329.6. I then divided 329.6/333 and got .989. Can I say I have 1.1% degradation after 7 months or is my approach all wrong. Please be gentle . Thanks for all your efforts here

 

[AlanSubie4Life]

I was playing around today with the energy screen to determine capacity of my 78.8 LR. I use the low SOC strategy and today the reading was at 16%. I really never charge above 35%. I know it’s better at a higher SOC. Here is what I did to get around the low SOC problem

I went to the trips screen. It tells me lifetime mileage and lifetime kWh used. Using my car I divided 6162/1473 and got 4.18. I then multiplied 4.18 x 78.8 for 329.6. I then divided 329.6/333 and got .989. Can I say I have 1.1% degradation after 7 months or is my approach all wrong. Please be gentle . Thanks for all your efforts here

This won’t work. Has no relation to capacity. I think you may have calculated what sort of range relative to rated you can achieve assuming an undegraded pack (not going to think about it further).

Just use the energy screen method. There will be a lot of inaccuracy regardless but you can get fractional SOC% (maybe) by doing a short drive and using one of the other pages to get the number. Then combine with the Consumption screen. Low SOC will still not be as good as high SOC for the calculation but it is possible there is less error (haven’t tried so it may be very inaccurate still).

You need three sig figs on all the numbers regardless - and even then there may well be inaccuracy depending on the accuracy of those numbers (for example the car may be simply interpolating the SOC%).

 

[AAKEE]

Interesting.

My M3 LR (2022) now showsbased in Teslamate, that after 2 years and 43k miles I lost ~ 7 kwh of capacity.

I did not run the battery health test though

Midlands…UK?

it is the LG Battery (78.8)?

 

[yessuz]

Midlands…UK?

it is the LG Battery (78.8)?

yes.
yes