90% the new recommended SOC?

[nvx1977]

FWIW, i've had my car charging to 60% from March till November, and I never had any issues with this. In October, I charged to full for a road trip. I had 308 miles that morning. However, it likely finished charging in the middle of the night, so I could have lost a few miles to the vampires and the phantoms.

As far as I'm concerned, this is a "cosmetic" issue. The actual capacity of the battery is fine; the estimation of range might get skewed in some cases. I'm not planning to change my charging habits for this.

 

[ℬête Noire]

FWIW, i've had my car charging to 60% from March till November, and I never had any issues with this. In October, I charged to full for a road trip. I had 308 miles that morning. However, it likely finished charging in the middle of the night, so I could have lost a few miles to the vampires and the phantoms.

As far as I'm concerned, this is a "cosmetic" issue. The actual capacity of the battery is fine; the estimation of range might get skewed in some cases. I'm not planning to change my charging habits for this.

There is one thing taking it to 100% occasionally helps with, it lets the battery pack balance properly which in turn help you charge faster at the top end of the battery when you are doing those large charges overnight (before and on trips) and before making large leaps during your trip where you need something close to your full battery capacity.

 

[ℬête Noire]

One thing about that video is I'm very confident the graph she's using is based on pre-Model 3 battery tech. I haven't seen proper amalgamation of data points yet but anecdotal points have come in of nil degradation after 10,000 of thousands of miles rather than the couple % points Model S & X usually see in that window.

 

[nvx1977]

There is one thing taking it to 100% occasionally helps with, it lets the battery pack balance properly which in turn help you charge faster at the top end of the battery when you are doing those large charges overnight (before and on trips) and before making large leaps during your trip where you need something close to your full battery capacity.

yep, and i think my occasional road trip will cover this. I've increased my set point now that it's cold. For range anxiety purposes mainly, but I guess it will help with this calibration issue as well.

One thing about that video is I'm very confident the graph she's using is based on pre-Model 3 battery tech. I haven't seen proper amalgamation of data points yet but anecdotal points have come in of nil degradation after 10,000 of thousands of miles.

High temps are much worse for Li batteries than high state of charge. But when you have both, not even Tesla chemistry can prevent degradation. If it's summer time, and live in hot climes, I would keep my charge set point lower just to be safe.

 

[ℬête Noire]

High temps are much worse for Li batteries than high state of charge. But when you have both, not even Tesla chemistry can prevent degradation. If it's summer time, and live in hot climes, I would keep my charge set point lower just to be safe.

Yes, I went back and added exactly that point to clarify why I'll be keeping mine at 85% daily. SE Texas, while not AZ hot, is exactly the sort of place where you shouldn't regularly push your battery.

The good news is that the Model 3's thermal management seems reasonably aggressive about blunting ambient heat. The trade-off is that you get a bit more vampire drain from that thermal management, and you regularly get puddles underneath the car, but I'll take that trade-off in a heartbeat.

 

[Dan123]

It doesn't list 90% as Trip. It brackets above 90% as "Trip", below 90% is bracketed as "Daily". This is not a change from that. Normally charge to 90%, at least once/month go to 100% (whether for a trip or just to send it through it's balancing cycle). Ironically the prior advisory was to disregard the Model 3 UI.

EDIT: Personally I'll probably still leave the top end of my everyday charge at about 85%, where it won't impinge on my regen ability. Above 85%, depending on ambient temp, and you start getting dots on the left of your regen/acel bar. Roughly 260mi easily covers my usage. Reason is that I live in a relatively hot region, and the effect of heat is multiplier of any degradation due to high charge.

Are charge limits in Tesla location based, like in Chevy Bolt? In other words, can I set one charge limit for home, and another for away from home?

 

[Knightshade]

Are charge limits in Tesla location based, like in Chevy Bolt? In other words, can I set one charge limit for home, and another for away from home?

Nope- though you can change the limit both in the car and remotely via the app

 

[Dan123]

Nope- though you can change the limit both in the car and remotely via the app

I find it difficult to change it precisely, because it doesn't seem to display numbers. I can't tell on the phone whether it is 88%, 89%, 90%, or 91%. Probably doesn't matter, but a little annoying.

 

[Knightshade]

I find it difficult to change it precisely, because it doesn't seem to display numbers. I can't tell on the phone whether it is 88%, 89%, 90%, or 91%. Probably doesn't matter, but a little annoying.

Agreed, it's on the long list of "dumb software things that should take 30 seconds to fix that Tesla doesn't appear to bother with"

See also- being able to set a "stop charging" time

 

[TexasEV]

I find it difficult to change it precisely, because it doesn't seem to display numbers. I can't tell on the phone whether it is 88%, 89%, 90%, or 91%. Probably doesn't matter, but a little annoying.

You couldn't charge it "precisely" even if it did display numbers. As battery state of charge can't be measured directly anyway, the displayed SOC (or rated range if you display that rather than % on the battery meter) is just an estimate that may be more or less accurate depending on how you've charged lately. There is no meaningful difference whether you're set at 89% or 90% or 91%.

Just set it in the car to approx. 90% and forget it, except when you increase to 100% for trips.

 

[BobAbooey]

When I picked up the car I was told keep at 90% also asked the Tesla mobile dude he also said same thing 90%

 

[ℬête Noire]

Are charge limits in Tesla location based, like in Chevy Bolt? In other words, can I set one charge limit for home, and another for away from home?

I haven't found anything, no. It does remember and revert to the charging rate that I lowered somewhat for the home charger, to keep from cooking another J-1772 station, and then reverts to maximum when I use a charger somewhere else (Destination or J-1772). But it doesn't have something like Bolt's explicit home-way setting linked to whether or not it should charge to 100% or to the 90% Hill Mode.

I wouldn't be surprised if some of those 3rd party apps (Teslifi, etc) have the feature?


EDIT: Curiously, I think it has learned where "home" is for parking. When I back up to the closed garage door it throws up the option to engage the automatic parking. I'm way too much a coward to let it take over on that, though, even when the door is open.

 

[ℬête Noire]

I find it difficult to change it precisely, because it doesn't seem to display numbers. I can't tell on the phone whether it is 88%, 89%, 90%, or 91%. Probably doesn't matter, but a little annoying.

I just set it appropriately, leave it charge and see where it came out. Tweak accordingly later. The more you use it the easier it is to eyeball the pixels, although I don't really change it that often anyway.

 

[Zaxxon]

I wouldn't be surprised if some of those 3rd party apps (Teslifi, etc) have the feature?

TeslaFi, at least, does. You can schedule a 'set charge limit' command based on a tagged location.

 

[kbecks13]

I can't stand that chick but the video was quite informative.

Man i thought it was only me...The video is meh at best, if you want actual information on these batteries i'd suggest reading through some of the articles on Battery University

BU-808b: What Causes Li-ion to Die? – Battery University

 

[nvx1977]

Man i thought it was only me...The video is meh at best, if you want actual information on these batteries i'd suggest reading through some of the articles on Battery University

BU-808b: What Causes Li-ion to Die? – Battery University

Second this. Tesla batteries are not magical, nor do they defy physics. They have significantly reduced the negative impacts of temperature and high voltage/charge to the point where it's pretty inconsequential where you set your charge setpoint. This is why Tesla is now recommending 90%. It's because you get the most utility out of the range, and I guess in some cases, it allows the car to give you a better SoC reading.

The reality is that the lower the voltage, the longer the battery will last, but there's a tradeoff between utility and longevity. I have a laptop battery that is now 12 years old and still in near perfect condition because I kept it between 20% and 35% SoC. This worked out fine because the laptop was never mobile and was plugged in 100% of the time.

 

[ngogas]

@voip-ninja liketesla is great. I like watching her videos. Pretty informative. I can’t stand you and your comments sometimes though. Just sayin. Haha

 

[ℬête Noire]

Man i thought it was only me...The video is meh at best, if you want actual information on these batteries i'd suggest reading through some of the articles on Battery University

BU-808b: What Causes Li-ion to Die? – Battery University

The cathode (positive electrode) develops a similar restrictive layer known as electrolyte oxidation. Dr. Dahn stresses that a voltage above 4.10V/cell at elevated temperature causes this, a demise that can be more harmful than cycling a battery. The longer the battery stays in a high voltage, the faster the degradation occurs.

This! While each contributes, combining heat + full charge + time sitting without discharge = very bad times. Each of these has an exponential rate of degradation as they rise, so combined things get bad fast. I've seen elsewhere that for time spent sitting at high charge, the curve tends to start turning the corner around 4hrs.

It's interesting to note:

An interesting discovery was made by NASA in that Li-ion dwelling above 4.10V/cell tend to decompose due to electrolyte oxidation on the cathode, while those charged to lower voltages lose capacity due to the SEI buildup on the anode.

That implies that it is bad to leave car sitting for extended periods below 70% or so charge, getting progressively worse the lower it is (a guess on that optimum SOC, because the 60% they give there won't map to what the car says is 60%, as the designers don't want to take it to true 100% and we know that Tesla's packs don't go all the way to 4.1V when "full").

 

[FSKT]

I don’t worry that much about the battery health unless your going to run the car into the ground... i’ll probably keep mine around four/five years or maybe less .

Yes, if you're looking at a 3-5 year ownership period, then really don't worry about charging/capacity, all that stuff.

I'm likely going to keep mine for a lot longer than that.

So just as it really makes no difference how you charge your battery if you're on a 3-year lease / buy-cycle or so, it also makes more sense to be more concerned about preserving/prolonging battery capacity when you've got a likely ten-year horizon (which, btw, is a longer time than any S has been on the road so far).

 

[Shock-On-T]

I admire the tenacity with which you continue to be factually wrong about this.

Meanwhile back in reality your argument has become "Best for driver to hurt battery life by charging to 100% every time as it makes it slightly less likely he by accident runs the car to 0 and then let's it sit for years without plugging it back in again, because ShockOnT has no understanding of how the post-roadster BMS works or what "liability" legally means"

As in, if it was a rental the driver would probably find it most convenient to charge to 100%, with little regard for the health of the battery. That is the extreme case.

As for batteries not self-discharging, I’m not sure where you got that information, but it’s not correct. All batteries self-discharge. The only variable is the rate, which depends on chemistry and temperature.