Long life NMC 811 Lithium battery (<3% loss for 200.000 km)

[jean.caissepas]

Feedback from a Chinese EV with NMC 811 batteries (article in English):

https://pushevs.com/2020/06/22/weltmeis ... gradation/

A+

[Christophe]

I do not know the 811 variant but it turns out that I have been testing an NMC battery since the end of 2016 ...

An element has just given up the ghost 6 months ago it still worked nickel !!

I no longer have any confidence in the effects of announcements on the batteries ... even more when it comes from Chinese !!

[Christophe]

Uh the NMC 811 already seems to be overtaken by the 90 and this article is almost 1 year old:

https://pushevs.com/2019/07/11/ncm-90-s ... ery-cells/

I didn't know there were variations in NMC

Read also:

https://forums.automobile-propre.com/to ... -38-22443/

[jean.caissepas]

I do not know the 811 variant but it turns out that I have been testing an NMC battery since the end of 2016 ...

An element has just given up the ghost 6 months ago it still worked nickel !!

The big difference between your battery and that of this car is that it has liquid cooling on this EV.
This is enough to explain the difference in lifespan of the fact that Li-Ions do not like heat (already at 40 ° they wear 2x faster ...)

Then the VE only did partial cycles, which reduced the battery life from 500 (0 to 100%) to 5000 cycles (20 to 70%)

In addition, the next NCMA batteries promise 3000 to 4000 cycles> 85%

1-s2.0-S1369702118309477-gr4.jpg (111.38 KB) Viewed 12084 times

[Christophe]

Possible...

I did some "heatwave" tests, but the NMC heats up much less than the Lipo which allows crazy Cs (up to 100C for the best current ones) ... I work at less than 5C which remains "reasonable" ...

And I have a BMS on it which seems of quality ...

This did not prevent an element from becoming weak ... after only a few dozen cycles ...

[ENERC]

Possible...

I did some "heatwave" tests, but the NMC heats up much less than the Lipo which allows crazy Cs (up to 100C for the best current ones) ... I work at less than 5C which remains "reasonable" ...

And I have a BMS on it which seems of quality ...

This did not prevent an element from becoming weak ... after only a few dozen cycles ...

The load curve also has a strong impact: EVs are charged at maximum at 2C from 10% to 70% (max), then more and more slowly to finish around 0,1C.
Charging above 2C above 70% kills the batteries. I had heard that PSA wanted to do it on the 208, but I believe they gave up.

[Christophe]

No worries with the charge curve: I charge at 5A max (so 0.125C max ...) with a dedicated lithium charger (so with the curve that goes well)

[phil59]

On an electric car, it is better to "bottle-feed", recharge little, but often.

On the other hand, faster charging, generally, up to 60% it goes super fast, up to 80%, it's very honest, and from 85% to 100%, it takes about the same time only 20 to 80% ...

On the ion, which has 16 kWh of battery, at more than 100 km, and not far from 000 years, I lost around 8% of autonomy, maybe 15 quick charges on this one, and a lot of charge from 20 to 70%, can of voltage difference to 100% of remaining energy on the cells ....

On that of my wife, in 3 years and 60km, the loss of range was less than 000-3%, and she had had more than 4 rapid charges (> = 200 kW).

The batteries do not hold too bad in general on EVs.

I still have a sony camcorder, almost 20 years old, and the "ion" battery still lasts between 30 and 45 minutes ...

I'm pretty confident in the batteries ....

[jean.caissepas]

I did some "heatwave" tests, but the NMC heats up much less than the Lipo which allows crazy Cs (up to 100C for the best current ones) ... I work at less than 5C which remains "reasonable" ...

Another graph on NMC 811 batteries:

[Christophe]

Thank you ... So we know the technology of CATL batteries which were quite talked about in early June: inventions-innovations / catl-ready-to-produce-batteries-planned-for-16-year-olds-and-2-million-km-t16472.html but without technological details.

So it would be NMC 532?

But I do not quite understand the reading of these comparisons, what should we see exactly?
That at 45 ° C the life is reduced ok ... but what else?

I can't see any significant differences between the NMC 811 and NMC 532 except the 150 extra cycles at 45 ° C?

For confidentiality it is rappé!

What does RT (cycling) mean?

Do you have other CATL slides? Source of this one?