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Trying to Understand Battery Degradation After 1 Year

Trying to Understand Battery Degradation After 1 Year

I have been scratching my head on the battery degradation stuff. I was expecting fairly rapid degradation during first year but our actual situation is that my car (11 months 12,000 miles) is a bit above 321 (ie a 1% loss) and my wife's car is still at 325 (it is 14 months old but only 6,000 miles). Is there a place to track actual degradation on the fleet? Is all this stuff about degradation just nonsense? I would love to hear what others are experiencing. Are we just lucky?

Magic 8 Ball | June 13, 2019
TexasBob | June 13, 2019

Cute M8B. I have read everything on there. Does not answer the question. Let me be clearer about it: What is the degradation people are typically experiencing in the Model 3?

Magic 8 Ball | June 13, 2019

If you read everything then you would understand there is no "typical". Everyone will experience something different. Some will have high degradation early on and some will not have it for a long time. The packs are an assembly and each assembly falls within a tolerance band. You will drive yourself nuts if you are trying to compare to others there are just too many factors that contribute, particularly what type of driver you are and how you charge the car.

FISHEV | June 13, 2019

Only way to measure degradation is to charge to 100% and run to dead (not good for battery) and measure actual range. Everything else is a guess by the car software.

Might be fun to get together with some Tesla owners and do that test on a local track to see what is actual.

Li-on batteries have a definitely life, 500 full charges/discharges is baseline but that would translate to 1,000 50% charges etc. (its not linear but gives you an idea of the order of magnitude). What has been seen with most EV installs in 10% loss in first 20,000 miles and then it levels out.

-TheJohn- | June 13, 2019

Our sample size is also very small and anecdotal.

kcheng | June 13, 2019

You can email or tweet the developers of the 3rd party apps, like Stats or Teslafi and see if they have aggregate data they'd like to share.

FISHEV | June 13, 2019

Don’t the apps just read the data the car provides? Those were said to be estimates based on usage, kind of like the mpg computers in ICE vehicles that always needed correction factors.

TexasBob | June 13, 2019

@Fishev Musk claims 1500 full charge/discharge cycles. https://www.teslarati.com/tesla-model-3-battery-module-replacements-elon...

Teslanene | June 13, 2019

I have 13k on my 6 month old. About half have been from supercharging. I will probably see a faster degradation than most, a lot of variables to consider.

markymaarty | June 13, 2019

to replace it with a brand new battery cost $5k to $7k? I was told by a Tesla advisor that a brand new battery replacement cost $30k! How many modules does the Model 3 have?

gmr6415 | June 14, 2019

@Teslanene, Look up some of Jeffrey Dahn's lectures on LI batteries (plenty on youtube). He states that fast charging is actually better for LI batteries as long as temperature is properly managed.

gmr6415 | June 14, 2019

@markymaarty, Some pretty good information at the link below on the M3 battery pack, but to answer your question it has 4 modules.

Tesla Model 3: Exclusive first look at Tesla’s new battery pack architecture

https://electrek.co/2017/08/24/tesla-model-3-exclusive-battery-pack-arch...