Anyone knows what those motors are

[Jughead135]

Oh boy, gotta hit funny on this one.

OK, fair enough—I was thinking forumites, not Elon Musk.

I said I was a noob, right...??

Question stands about battery charge levels, though....




PS: Laugh away, but: JB?

 

[aerodyne]

Can you expand on this, please? (I'm a noob, no idea who EM and JB are....)

I've read that high states of charge are OK for a short duration (i.e., charging all the way up before a long leg is fine; right before parking for a week is not); and that VERY low charge (2% or less) should be avoided altogether. Other than that, I've seen numbers anywhere from 75% - 90% as "targets" to charge to. I've been using 80% for lack of any better information.

Am I overdoing it, to exceed 70%??

Elon Musk...JB Struabel, battery guru.

The 30-70% answer was to the question, what states of charge should I use to keep the battery and car for 20 years?

No, 80% is fine. Only slight gain to be had by staying between 30-70% per Musk, in a later tweet.

 

[dark cloud]

Elon Musk...JB Struabel, battery guru.

The 30-70% answer was to the question, what states of charge should I use to keep the battery and car for 20 years?

No, 80% is fine. Only slight gain to be had by staying between 30-70% per Musk, in a later tweet.

Without doing a ton of research, from what I see JB oversaw the development but on the business end, he is an engineer in energy systems, but more of an executive of the company, whereas the battery expert is Jeff Dahn, contracted through his research done at Dalhousie university.

Tesla Battery Expert Jeff Dahn Raves About A New Battery Chemistry

Research

I am no battery expert. From everything I have read the best over-arching principle for longevity is to keep a lithium ion battery away from the extremes and in the middle of its SOC range as much as possible. So if you use 20% on a daily basis on average, in theory it is best to charge to 60% and run it to 40%
Would it make a difference to start at 70% and go to 50%? Probably not. 80% down to 60%? Probably not. And if there is the possibility that you might need that range then that is what the driver is going to do.

(I was going to stop here, but feeling energetic this morning, I will keep going....)

Are there anecdotes of owners charging to 90% and going down to 70% daily, and having very little loss (degradation) over 100,000 miles? yes. but will they start reposting in a few more years at 200.000 miles and report that maybe they were wrong and they have 6% more degradation? Probably not. How many people actually drive up to 200,000 on any car? Usually it gets sold/traded in and the next 2 or 3 owners don't know the history of the battery charging so its irrelevant.

Are there anecdotes of people charging always in nice weather (California) never higher than 70% and having more degradation than average? yes. But with data collection there is always going to be some outliers; there are other factors at work. I know reading posts on the internet, say if you get 7 people in one thread who claim some condition it seems like fact, but it could be those are the only 7 negative outspoken people with that experience in 1000 samples; and the other 993 have the exact opposite experience. We need all 1000 people to report for it to have any meaning.

From Battery university (website, not actual university) two takeaways I see in the following graph:

*Every 0.1V drop below 4.2V/cell doubles the cycles
*lowering the SOC to 50% increases the life of the battery by 44-130%

But the second point above, does that mean running it down to 0%? I don't think so...

Elon is quoted as saying go to 90%, its fine, two thoughts:

Your car says 90%, but on some reduced capacity batteries, "battery gate" where some unlucky fellow's voltage is reduced to say 4.08 volts, the new 90% is actually 75%, right? (haven't done the math, just for demonstration purposes) The point is 90% is not really 90%.

And I haven't considered this thought before, is he doing that in the new satellites? You would want them to last as long as possible of course. I would guess they are being charged to the middle of the range as much as possible? I would be very surprised if they are being charged to 90% via solar on a daily basis. (given that 4.2V/cell is 100%)

edit: and sorry, wrong thread for this post, however battery issues are slightly related to the running of coolant pumps

 

[aerodyne]

Interesting. Do they sound like this? Video makes it seem louder than it is, but still very noticeable and just started recently. I assumed it was fan problem.

I think something is hitting the fan blade(s). This does not sound normal to me.

 

[Chaserr]

And I haven't considered this thought before, is he doing that in the new satellites? You would want them to last as long as possible of course.

They probably solar charge to 50% or whatever they can get away with since those satellites are extremely low orbitand will expected to deorbit in as little as roughly 5-10 years. Even the ISS is low enough to need to compensate for small amounts of atmospheric drag to remain in orbit, and Starlink doesn't carry enough fuel or get refueling missions to keep them up - they will just be periodically replaced.

Batterygate is on topic - the fuel pumps are now run more often specifically to avoid the thermal runaway fire producing temps that caused batterygate downgrades. the same code that downgrades batteries is what turns on the pumps - and in fact, thinking about it, one or two modules with anomalous high temperature readings while parked could very well be the "trigger" event that gets batteries capped in the first place.