Live data from Hacker News

Tesla Model S battery degradation data

steinbuch.wordpress.com

1–10 of 257 posts

Re: Tesla Model S battery degradation data

#2
What could explain the graphs and cycle stability is that Tesla does not deplete the battery pack below a certain percentage of the real battery capacity or over a threshold... basically they keep the battery pack well beyond the critical ranges where batteries degrade from simply idling, and they "undersell" the pack capacity.

Re: Tesla Model S battery degradation data

#3

What could explain the graphs and cycle stability is that Tesla does not deplete the battery pack below a certain percentage of the real battery capacity or over a threshold... basically they keep the battery pack well beyond the critical ranges where batteries degrade from simply idling, and they "undersell" the pack capacity.

I think most/all EV's do this.

Re: Tesla Model S battery degradation data

#4

What could explain the graphs and cycle stability is that Tesla does not deplete the battery pack below a certain percentage of the real battery capacity or over a threshold... basically they keep the battery pack well beyond the critical ranges where batteries degrade from simply idling, and they "undersell" the pack capacity.

I think most/all EV's do this.

They do it to different degrees.

Re: Tesla Model S battery degradation data

#6

What could explain the graphs and cycle stability is that Tesla does not deplete the battery pack below a certain percentage of the real battery capacity or over a threshold... basically they keep the battery pack well beyond the critical ranges where batteries degrade from simply idling, and they "undersell" the pack capacity.

Yup and that's totally fine in my book since they're selling a rated range.

My single datapoint at 60k is I've seen only 2% degradation which is phenomenal.

Re: Tesla Model S battery degradation data

#7
Average life of ICE vehicles can't be 266kkm, that's absurdly low. Most of people I know have bought vehicles with that mileage and used it for another 100kkm after that at some point in their life (think first/second car, second family car, etc.). It's important to know that especially in Central/Eastern Europe, you can never trust the car's odometer - even the cars I'm talking about had probably more than 350kkm when bought.

Re: Tesla Model S battery degradation data

#8
> The red fitted line has a slope above 60.000 km (say 40,000 miles) of 1% per 50.000 km (30,000 miles).

I'm going to bring this up because I think it's both interesting, and sometimes it comes up on its own and detracts from the conversation with conjecture (and sometimes harsh assumptions) until covered adequately[1] - different countries have different conventions for whether they use a comma or period for a thousands separator, and in those languages if they also speak in English sometimes, they may choose to continue using a period as a thousands separator as is convention in their country, even if the predominant language in their country is not English, and there are circumstances which might make that more common for some people.[2]

In this case, we have what appears to be switching convention when switching unit systems, which is interesting. I'm not sure if it's more or less confusing in the end, but there's not really any standardization of this as far as I know, so it's all good.

1: https://news.ycombinator.com/item?id=14970002

2: https://news.ycombinator.com/item?id=14862695

Re: Tesla Model S battery degradation data

#9
This is fundamentally flawed because lithium batteries mostly degrade not because of amount of use, but because of time (and their charge state and temperature during this time). No matter if used or not, they will lose capacity. The rate of capacity loss is mainly dependent of average charge (best is 40%, worst is 100%) and temperature (best is 5 degrees C, the higher the worse).

(This is also why phone batteries fare so badly: they are often near 100% charge at 36.6 C in your pocket)

http://www.sciencedirect.com/science/article/pii/S0378775316...

Re: Tesla Model S battery degradation data

#10

Average life of ICE vehicles can't be 266kkm, that's absurdly low. Most of people I know have bought vehicles with that mileage and used it for another 100kkm after that at some point in their life (think first/second car, second family car, etc.). It's important to know that especially in Central/Eastern Europe, you can never trust the car's odometer - even the cars I'm talking about had probably more than 350kkm wh…

I have seen plenty of cars not make to 165_000 miles, those that do are often near the end of their life. Mine is beat and barely holding together and it is at 97_000 miles.
Post reply on HN