Do i have to keep it plugged in everyday?

[.Slug]

Wow some of you are only losing 1 mi per day on standby???

My car loses at least 1.5 to 2% per day (~10 miles) with sentry/hvac/dashcams all off. The car still tells me this is "optimal" amount of loss.

So, I've learned how to combat my high loss per day in standby.... use "power off" from the safety settings. This has reduced my standby/parked consumption to ALMOST ZERO. I've been doing this for about 3 days now. I've eliminated the major consumption while parked/between drives. In two days, it only read 0.2%. Wonderful! Not sure why more people don't talk about the "power off" feature.

The best way to do this to prevent the computer from turning back on is to "power off" with the driver's door open. When doing it this way, things don't turn back on when you open the door if you powered off with it closed. When you close the door after you "power off" with it open, things stay off! Wish I knew this a year ago. lol

My estimated miles after charging are now increasing as the system learns my new consumption with power off utilized.

 

[johnny_cakes]

So, I've learned how to combat my high loss per day in standby.... use "power off" from the safety settings. This has reduced my standby/parked consumption to ALMOST ZERO. I've been doing this for about 3 days now. I've eliminated the major consumption while parked/between drives. In two days, it only read 0.2%. Wonderful! Not sure why more people don't talk about the "power off" feature.

The best way to do this to prevent the computer from turning back on is to "power off" with the driver's door open. When doing it this way, things don't turn back on when you open the door if you powered off with it closed. When you close the door after you "power off" with it open, things stay off! Wish I knew this a year ago. lol

My estimated miles after charging are now increasing as the system learns my new consumption with power off utilized.

Nice tip! Is there any downside to doing this? Will the HV battery still charge the LV battery if LV capacity gets low? Lead Acid LV (for those of us who have that) don't like low SoC.

 

[davewill]

Nice tip! Is there any downside to doing this? Will the HV battery still charge the LV battery if LV capacity gets low? Lead Acid LV (for those of us who have that) don't like low SoC.

One thing I can think of is the that car might not be checking for and installing updates while it is off. Fairly minor, and if you get a notification, you can always just leave the car on when you need to install it.

 

[Ther0ck]

Might wanna read the Model 3 user manual.

Model 3 Owner's Manual | Tesla

Learn about your vehicle’s battery and battery best practices.

www.tesla.com

High Voltage Battery Information​

About the High Voltage Battery​

Model 3 has one of the most sophisticated battery systems in the world. The most important way to preserve the high voltage Battery is to LEAVE YOUR VEHICLE PLUGGED IN when you are not using it. This is particularly important if you are not planning to drive Model 3 for several weeks.

Note
When left idle and unplugged, your vehicle periodically uses energy from the Battery for system tests and recharging the low voltage battery when necessary.

There is no advantage to waiting until the Battery’s level is low before charging. In fact, the Battery performs best when charged regularly.

 

[Kozluv]

Not much if we look at calendar aging.

I took myself the liberty to change LFA to LFP, so others dont get confused.

Like this;
View attachment 932020
Or this;
View attachment 932021

As we can see, there are differences between the main chemistries. But not very big differences.

LFP’s degrade about the same as NMC and NCA does if looking in the first one or two year time window (we can use teslalogger.de for this).

What we know is that LFP can do much higher cycle numbers and they are relatively non sensitive to large cycles, which in turn lead to the conclusion that the degradation we see for the first couple of years is more or less calendar aging only.

Tesla tell us to charge to 100% at least once a week. This is not due to the chemistry ”needing” this but it is to help the BMS keep the correct countinh of the energy in the battery ( for minimizing the risk of getting stranded due to low SOC).

Is it best to only charge to 50% daily and 100% if needed with a lfp Tesla? I live in Arizona and it’s a hot climate. What are the best practices to reduce battery degradation. There is a lot of information and somewhat conflicted. Tesla said charge 100% daily but other data shows charging to 50% is better for longevity of battery.

 

[AAKEE]

Is it best to only charge to 50% daily and 100% if needed with a lfp Tesla? I live in Arizona and it’s a hot climate. What are the best practices to reduce battery degradation. There is a lot of information and somewhat conflicted. Tesla said charge 100% daily but other data shows charging to 50% is better for longevity of battery.

For LFP and calendar aging, the value that is good to stay below is 70%

Look at the right part, for LFP. Calendar aging cut in half if the SOC is at 70*% or below.

This graph show calendar aging and it is induced by time x temperature x SOC (SOC as per the graph above).
We can reduce time by charging shortly beforte the drive. Charging late to 100% once a week and then driving it down to 70% or below will keep the calendar aging low.

 

[STS-134]

For LFP and calendar aging, the value that is good to stay below is 70%

Look at the right part, for LFP. Calendar aging cut in half if the SOC is at 70*% or below.
View attachment 933233

This graph show calendar aging and it is induced by time x temperature x SOC (SOC as per the graph above).
We can reduce time by charging shortly beforte the drive. Charging late to 100% once a week and then driving it down to 70% or below will keep the calendar aging low.

If I had a car with LFP batteries, I'd do the following:

• Never charge to 100% unless I'm immediately going to use at least 30% immediately (the reason to charge to 100% is to avoid the BMS from drifting but if you aren't immediately going to use at least 30%, it doesn't matter if it drifts by 20-30% even if you are only charging to 50%)
• Always charge to 100% any time there's a chance I'll run below 20%

So if, for daily usage, I'm using only 10% then it could be quite a while between 100% charges. But that's OK because the potential drift of the BMS from the actual SoC levels only matters when you're going below 20%. I think Tesla just doesn't come out and say this because the bad PR they'd get from cars running out of battery when the gauge still shows 10-20% remaining would be worse than their vehicles showing double the degradation on average after 5+ years of ownership.

 

[Kozluv]

For LFP and calendar aging, the value that is good to stay below is 70%

Look at the right part, for LFP. Calendar aging cut in half if the SOC is at 70*% or below.
View attachment 933233

This graph show calendar aging and it is induced by time x temperature x SOC (SOC as per the graph above).
We can reduce time by charging shortly beforte the drive. Charging late to 100% once a week and then driving it down to 70% or below will keep the calendar aging low.

Is it okay to drive with a lfp tesla in the 5-20% soc range, or is there more of a chance that the battery could die because of the bms issue?

 

[AAKEE]

Is it okay to drive with a lfp tesla in the 5-20% soc range, or is there more of a chance that the battery could die because of the bms issue?

I would say that Tesla use the variable buffer to counter part of this. If you charge like tesla say, at least one 100% charge eack week or more than one a week, it probably is.
But if you start deviating from Teslas advice, you might run into problem if you go low in SOC.

Giving advice about LFP cars is a little harder or delicate compared to the LR/P cars. Deviating from Teslas charge to 100% ”at least once a week” ”and leave the setting at 100%” will most probably reduce thje BMS ability to measrue the SOC. This need to be fully understanded by anyone trying to reduce calendar aging.

As it is a lot of posts about this lately and it is hard to keep track how much of this someone that asks a question has understood I more and more is drawn to the idea to say ”just follow the Tesla advices, period”. No one will be happy when getting stranded in a hurry os a busy day.

So, for the ones that clearly understands what can be the issue with low SOC strategy with LFP cars its not a problem to use the low SOC strategy as long times of not charging to 100% should not be combined with driving the car down to low SOC. I guess 20% is a good marging if the car has not been charged to 100% multiple times lately.

 

[Kozluv]

I would say that Tesla use the variable buffer to counter part of this. If you charge like tesla say, at least one 100% charge eack week or more than one a week, it probably is.
But if you start deviating from Teslas advice, you might run into problem if you go low in SOC.

Giving advice about LFP cars is a little harder or delicate compared to the LR/P cars. Deviating from Teslas charge to 100% ”at least once a week” ”and leave the setting at 100%” will most probably reduce thje BMS ability to measrue the SOC. This need to be fully understanded by anyone trying to reduce calendar aging.

As it is a lot of posts about this lately and it is hard to keep track how much of this someone that asks a question has understood I more and more is drawn to the idea to say ”just follow the Tesla advices, period”. No one will be happy when getting stranded in a hurry os a busy day.

So, for the ones that clearly understands what can be the issue with low SOC strategy with LFP cars its not a problem to use the low SOC strategy as long times of not charging to 100% should not be combined with driving the car down to low SOC. I guess 20% is a good marging if the car has not been charged to 100% multiple times lately.

So if I adopt charging to 50% every day late at night except for once a week I charge to 100% for bms. This strategy could reduce aging degradation? I don't need a 100% charge, my commute to work daily is around 10 miles.

 

[AAKEE]

So if I adopt charging to 50% every day late at night except for once a week I charge to 100% for bms. This strategy could reduce aging degradation? I don't need a 100% charge, my commute to work daily is around 10 miles.

If I charge my Performance, not a LFP battery, to 55% I have 55% of the range to use.

If you charge a LFP to 50%, the buffer probably goes up to from 4.5-ish to 10% or so, reducing the 50% usable with 5% to about 45%.
On top of this you probably need a safe margin like 20% or so if you do not follow the 100% once a week.

If 45-20% is enough, I would do like that.

(Also, I feel that I rather would like to give a more restricted advice than how I would or could do it myself, as its important to understand the risk of gettibg stranded and how to conquer it)

 

[STS-134]

If I charge my Performance, not a LFP battery, to 55% I have 55% of the range to use.

If you charge a LFP to 50%, the buffer probably goes up to from 4.5-ish to 10% or so, reducing the 50% usable with 5% to about 45%.
On top of this you probably need a safe margin like 20% or so if you do not follow the 100% once a week.

If 45-20% is enough, I would do like that.

(Also, I feel that I rather would like to give a more restricted advice than how I would or could do it myself, as its important to understand the risk of gettibg stranded and how to conquer it)

Do you think it would take multiple charges to 100% to "recalibrate" the BMS? I would think that letting it see the top end with a single charge to 100% should do it. And doesn't it also need to see the bottom part of the range to in order to know how much capacity the battery actually has?

 

[AAKEE]

Do you think it would take multiple charges to 100% to "recalibrate" the BMS? I would think that letting it see the top end with a single charge to 100% should do it. And doesn't it also need to see the bottom part of the range to in order to know how much capacity the battery actually has?

There would per principle be only one full charge needed, as it is counting of energy that is used to make the BMS certain of the actual energy content.
A charge until it stops should do this but I am not sure if the BMS reduces the buffer at the same time.

( my BMS was fairly off last summer and I could see with my bare eyes that is was, bit still took months for it to readjust. There was a lot of clues that the BMS probably ignored…if the BMS does that, it might be slow on reducing the buffer also.
I do not know the upper limit of the buffer somthe question if it is possible to reach a
situation where it is too low?

 

[.Slug]

Just following up with my replies in this thread. My daily stanby turned out to be more like 4 to 6% over the last week in 4 hours between drives. I discovered my poor "phantom" drain from standby was being caused by the Tesla mobile app itself. I unistalled it and re-installed it. No more high standby consumption. Maybe recent updates made it bug out. But now I'm getting the less than 0.8% of standby consumption and no need to "power off."

 

[DrChaos]

Is it best to only charge to 50% daily and 100% if needed with a lfp Tesla? I live in Arizona and it’s a hot climate. What are the best practices to reduce battery degradation. There is a lot of information and somewhat conflicted. Tesla said charge 100% daily but other data shows charging to 50% is better for longevity of battery.

Charging to 50% is better for longevity for sure. Charging to 100% with LFP is needed to get a better calibration estimate of the state of charge, it's difficult to determine in LFP. If you are really careful and don't drive much and stay far away from the low end so you don't get stranded, you don't have to charge to 100% as often as Tesla says.

They're trying to prevent service calls and angry people saying they got stranded in a new Tesla, which their direction will prevent.

Given you live in Arizona, I would charge to 100% once a week a bit less, then 50% all other days as needed. It's combination of heat * high state of charge which degrades batteries faster. So if you can, charge the 100% in colder times and then drive off soon.

 

[STS-134]

Given you live in Arizona, I would charge to 100% once a week a bit less, then 50% all other days as needed. It's combination of heat * high state of charge which degrades batteries faster. So if you can, charge the 100% in colder times and then drive off soon.

But with a daily commute of just 10 miles, that battery is going to be forever above 50%, even if it's charged to 100% just once a week.

 

[AAKEE]

But with a daily commute of just 10 miles, that battery is going to be forever above 50%, even if it's charged to 100% just once a week.

Good thing is, as soon as it is below 70% displayed SOC, the calendar aging drops like a stone.
The important thing is getting it below 70%.


(I think you know this, so the picture is for other viewers mainly).

 

[STS-134]

Good thing is, as soon as it is below 70% displayed SOC, the calendar aging drops like a stone.
The important thing is getting it below 70%.


(I think you know this, so the picture is for other viewers mainly).
View attachment 933868

Yeah but 50 miles/week on commuting? That's going to be a significant portion of time spent above 70%. Which means charging to 100% should really be done only before a drive that consumes at least 30% of the battery. With my vehicle (NCA batteries), I only charge to 100% 3 or 4 times a year unless taking road trips, and only before drives that consume at least 30-40% of the battery in one go.

 

[AAKEE]

Yeah but 50 miles/week on commuting? That's going to be a significant portion of time spent above 70%. Which means charging to 100% should really be done only before a drive that consumes at least 30% of the battery. With my vehicle (NCA batteries), I only charge to 100% 3 or 4 times a year unless taking road trips, and only before drives that consume at least 30-40% of the battery in one go.

Yes, thats true.

I know that I could use a more agressive approach myself than I actually would dare to tell, of I had a LFP Tesla and did drive very little.

Giving advice to *anyone* ( = that might miss a few important things, and then get stranded and mot happy) probably need to be adjusted to be “safe” when it comes to the actual range vs displayed.

One issue is not knowing the details of the LFP cars. I have a collegur that ordered a Y LFP so I will do some SMT checkups to learn.

 

[STS-134]

Yes, thats true.

I know that I could use a more agressive approach myself than I actually would dare to tell, of I had a LFP Tesla and did drive very little.

Giving advice to *anyone* ( = that might miss a few important things, and then get stranded and mot happy) probably need to be adjusted to be “safe” when it comes to the actual range vs displayed.

Yeah, and I understand why Tesla gives the advice it does. But here is where people come to learn and I'll give advice for optimal battery management, along with the reasoning and a warning that if you don't charge to 100% before driving below 20%, you may get stranded.

Last month, I was at Disneyland and staying at a hotel without a EVSE. So I didn't follow my usual procedure of using Scheduled Departure to charge to 100% 1 hour before departing, but I drove to the Mickey and Friends parking structure on my last day there, timed things so that it reached 100% about half an hour past midnight, drove the car back to the hotel at around 1:15 am, and let it sit overnight at close to 100% -- the only time I have ever done this since I bought the car. I figured it's not *that* bad as it was only 9-10 hours max. That's less than 1/800 of the entire year.