What’s the best Charge Percent

[AlanSubie4Life]

Do note that the OP apparently does not have his car yet, so I was trying to provide details on how the car works. Not just respond to his question about what to do with "just don't worry about it."

Everyone keeps coming up with all sorts of rules and crap

I didn't provide any rules. Unless "do what Tesla recommends" is a rule?

You were the one that stated just because the software allows 50-90%, then all of them are equally valid. That's a really long stretch. So what makes 50% valid and 49% invalid. That's just a software setting.

That's the software and that's what Tesla decided to make the limits. It's factual. For whatever reason they decided people should charge to 50% minimum if they are plugged in and the vehicle is not attended. Good enough for me.

As I said, likely none of this really matters all that much if you just do what Tesla says in the owners manual and don't ignore any warnings that say "this will degrade your battery".

Tesla provides no further guidance than to plug the vehicle in whenever you can when it's not in use (see captures from the owners manual above for the actual verbiage, please don't parse the prior statement), and the limits provided are what they are.

I do agree with you that people shouldn't worry about it beyond that; as I said, if they experience large battery degradation, it's quite likely there was nothing that could have been done about it anyway. (That is the track record for Model 3 so far anyway.)

 

[TMThree]

I remember a tweet to Elon asking 90% to 10% better than 80%-10% and he said 80%. I personally keep my max right around 60% for my city/work driving.

Correct answer right here, but only if you are able to let it sit that low. For me I do the same - charge to 65% for daily work commutes. That lets me arrive with 55%, which is close to neutral. Then I get home with 45% remaining. Plenty left over if I need to hit up the store or something.

You should still charge to 90% on weekends or intermittently so the cells can balance and not start thinking your range is reduced.

Chart brought to you by some other thread on this forum:

 

[AlanSubie4Life]

Correct answer right here, but only if you are able to let it sit that low. For me I do the same - charge to 65% for daily work commutes. That lets me arrive with 55%, which is close to neutral. Then I get home with 45% remaining. Plenty left over if I need to hit up the store or something.

Chart brought to you by some other thread on this forum:

Seems like a reasonable charging strategy that works for you.

Just a few comments:

1) Note that this chart is not physical or based on any actual battery. It's just an illustration of what might happen for some battery (see the original post). @Zoomit made that pretty clear when he posted it.

2) Note it's a storage stress curve, to the extent it is even valid. This stress isn't necessarily the only factor when not storing a battery (when you're using it every day you are not storing it). There's a tradeoff with starting at a lower level charge because it makes low levels of charge more likely.

There is (apparently) also an issue of phase transitions within the battery which occur at a slightly-above-mid-range %. Those occur only when you're using a battery...and they could create some stress.

The discussion in that other thread is not specific to the Model 3. It's hard to know how Model 3 will behave specifically and to what extent the various phenomena actually apply and how to weight them.

Pretty sure that specific variations within Tesla's guidance aren’t going to make a huge difference to long-term results. There may be some correlation in degradation with certain habits, but my guess is the outliers will be driven by other phenomena.

Obviously it's a guess. I have no idea!

 

[TMThree]

While some characteristics are modified, ultimately we're using a lithium battery. It should apply to the Tesla as much as it applies to my cell phone.

Even if it's not a 100% match, no one is going to be able to say charging your car to 65% is worse for the battery than charging to 90% or 80%.

 

[ewoodrick]

While some characteristics are modified, ultimately we're using a lithium battery. It should apply to the Tesla as much as it applies to my cell phone.

Even if it's not a 100% match, no one is going to be able to say charging your car to 65% is worse for the battery than charging to 90% or 80%.

And a engine is an engine.

But the reality is that there are a log of BIG difference int he batteries. The differences between the Model S battery and the Model 3, just isn't the size.
Nissan made some changes in the battery chemistry to combat some of the stress that the original batteries were getting in heat. This kept batteries from significant degradation.

Indeed the post graph is for reference and not indicative of the Tesla Model 3 story.

 

[edigest]

What’s the best way to charge to minimize battery degradation.

70%.

Tesla Battery Expert's Recommendation For Maximum Battery Life - Video

P.S. 70%, 80%, 90% are all acceptable, depending on your specific needs.

 

[darth_vad3r]

Me pedantic? You were the one that stated just because the software allows 50-90%, then all of them are equally valid. That's a really long stretch. So what makes 50% valid and 49% invalid. That's just a software setting.

Everyone keeps coming up with all sorts of rules and crap. Don't worry about the battery.

I think you are misattributing that "equally valid" post of @Dr. J 's to @AlanSubie4Life ...

Au contraire!


Since the car won't squawk at any charging level between 50% and 90% (IIRC), all such charging levels are equally valid, per the manual. QED.

Edit: Assuming the two bold faced phrases are functionally equivalent. Which now that I think about it, they may not be.

 

[darth_vad3r]

Me pedantic? You were the one that stated just because the software allows 50-90%, then all of them are equally valid. That's a really long stretch. So what makes 50% valid and 49% invalid. That's just a software setting.

Everyone keeps coming up with all sorts of rules and crap. Don't worry about the battery.

... and just to continue the pedantry ... someone saying "50-90% are equally valid", does not make 49% invalid, nor does it impy it is somewhat less valid, or equally valid. It's not saying anything about 49%.

At worst you'd say it's maybe implying that 49% is slightly less valid ... but not invalid.

I'm guessing they chose the min. 50% because 50% is the ideal storage SoC, so if you're storing it you just slide it to minimum and it keeps the battery happy while you are heartlessly ignoring it for a long period of time.

 

[darth_vad3r]

Yep I got the warning recently charging to 93% a few times in a row. I think 3.

In case anyone wants to see the warning for themselves, I went back through my logs and figured out what actually happened. It seems to have reset the counter before I thought it had, so it wasn't counting over multiple days, but actually just counting 2-3 charge events from one single plug-in.

Set the target to 90%, let it complete, then set it to 91%, let it complete, then repeat for 92, 93 ... when you return to your car it will give you the nag and prompt you to ignore it or lower your limit. You can do this, for example, all in one ChargePoint session.

 

[Trevor B]

Ignore the other postings.

42 is the best charge percent. It was calculated by a very big computer over a very very long time and proven to work.

Haha! @M3SWFL disagrees (probably didn't get the joke)

 

[pdx_m3s]

I charge to 70% and plug-in as soon as it dips into the 40s, which is about every 3 days.

 

[darth_vad3r]

I charge to 70% and plug-in as soon as it dips into the 40s, which is about every 3 days.

So 21% in 3 days to hit 49% or lower?

Is plugging in a hassle? Why not do 57% and plug in every day? If it’s a hassle I can understand. If it’s easy I’d do that ... then you can up the charge target at night if a new plan comes up without trekking out to the car to plug it in. Also you can precondition every morning with shore-power assist

 

[Dogtone]

New Nifty tool! - Best practices for battery charge level for long battery life

 

[ewoodrick]

wasnt there this survey a few years ago where Model S owners who regularly just charged to the non-long range limit (93%???) had the least range degradation?

Don't know, but there are a number of Model Ss that Supercharge multiple times every day and are probably near 500,000 miles.

 

[pdx_m3s]

So 21% in 3 days to hit 49% or lower?

Is plugging in a hassle? Why not do 57% and plug in every day? If it’s a hassle I can understand. If it’s easy I’d do that ... then you can up the charge target at night if a new plan comes up without trekking out to the car to plug it in. Also you can precondition every morning with shore-power assist

I wouldn’t say it’s a hassle, just one less thing to do when I get home from work. I’ll probably reconsider my charging habits once winter hits and I start preconditioning the cabin before I leave.

 

[TimothyHW3]

Don't know, but there are a number of Model Ss that Supercharge multiple times every day and are probably near 500,000 miles.

Yes, and on their 3rd or 4th battery pack. Tesloop got a replacement every 180,000 miles. Granted it was an X or S and M3 might have a battery chemistry that is better, but you still want to minimize the degradation.
Mainly because Tesloop used up the battery within the warranty and over a short period of time. Because just by having a battery sitting there over longer periods of time, like 8- 10 years, will add degradation on its own.

And the second thing is Model 3 warranty is rated at only 120,000 miles and 70%. You wouldn't want to end up with 75% at 130,000 miles, trust me...If you can keep the battery between 45-75% daily and only rarely charge to 90-100% , do it.

Having 100 less rated miles on the car will make it probably hard to sell after 6- 8 years.

 

[bwilson4web]

Tesloop got a replacement every 180,000 miles. Granted it was an X or S . . .

Before they shut it down, they were running a Tesla shuttle between Los Angles and Las Vegas using SuperChargers. At the Munro & Associates EV conference, the owner claimed the Tesla policy forbidding use of SuperChargers for commercial applications was due to them. They shutdown when California notified them of labor violations.

Regardless, getting 180,000 miles is a reasonable vehicle life. More than a few ICE cars are ready for a rebuild and catalytic converter replacement at 180,000 miles. Along the way, cam chain replacement, spark plugs, oil and filter changes, and brake pads. In Alabama, about once every two weeks I see the blue cloud from a worn out engine on a dented body with plastic sheet covering a side or rear window.

Bob Wilson

 

[TimothyHW3]

Sure, but the guy above me thinks or claimed they ran the 500,000 miles on the first battery while supercharging daily.

Plus I doubt they supercharged always. I am sure they had a wall charger they used overnight too. Even if they abused the Suc pokicy because it was free. And I really doubt the battery had a good health after the 120,-150000 miles

But like you said, some ICE cars will have motor replacement after 60,000 miles. I know a lot of BMWs that do

 

[Candleflame]

Don't know, but there are a number of Model Ss that Supercharge multiple times every day and are probably near 500,000 miles.

yeah those 0 to 100% supercharger cars all have damaged batteries and have regular pack replacements.

 

[TMThree]

And a engine is an engine.

Different sizes, different methods of ignition, but function on the same premise.

Nissan made some changes in the battery chemistry to combat some of the stress that the original batteries were getting in heat. This kept batteries from significant degradation.

Right. The leaf "only" suffers from massive double digit degradation losses in a 2-3 year window. Active cooling would have been better than anything they did.

Indeed the post graph is for reference and not indicative of the Tesla Model 3 story.

Actually it is perfectly valid. But believe whatever you want. Magic lithium batteries that doesn't behave like lithium *rolls eyes*