charge everyday or once in 3 days

[Venk Dakshin]

Hello

i drive about 90 miles round trip for work.

I heard battery degradation is dependent on discharge cycles and state of charge. I typically keep the state of charge between 80% ( i drive 10-13% as soon as i get to 80) and 20% ( i charge as soon as i get close to 22%)

if I do frequent top ups to 50 or 60% , wouldn't the number of discharge cycles increase?

 

[LoudMusic]

So you drive 90 miles every weekday?

If you only charge once every three days, and on the third day you have to drive more than 90 miles, what's your option for charging?

I would set it to 80% and charge every day for convenience.

Charging / discharging "cycles" are counted as cumulative 100% sessions. Meaning if you charged 30% on three different sessions you would have charged 90% of one cycle.

Every time you press the accelerator you are starting a new discharge. And every time you let off the accelerator you are starting a charge (regen braking).

 

[shahryaran]

Calendar aging degrades more than cyclic aging

 

[ATPMSD]

I suggest it is not worth your brain cells to worry about this. If you really care there are thousands of posts on this subject with a wide range of opinions.

Tesla’s “official” position is:

”The most important way to preserve the high voltage Battery is to LEAVE YOUR VEHICLE PLUGGED IN when you are not using it.” (page 172 of Model Y manual)

 

[Darmie]

1 discharge cycle equals 100pct to 0 pct. As Shahryaran mentioned, Calendar aging is move of an issue.
The best defense against calendar aging as per the below chart is to not keep the battery at a high state of charge for any length of time. The lower state of charge you can get away with the better when you car is sitting. I recommend to charge every night and use schedule charging to have the car ready to depart at the time you leave for work. That way the battery is not sitting at a high state of charge overnight. Ideally if you are at work for 8 hours, you would want to battery pack to be no higher than 50pct. As you see on the chart below, calendar aging increase more past 50pct.

 

[father_of_6]

if I do frequent top ups to 50 or 60% , wouldn't the number of discharge cycles increase?

No, the number of discharge cycles won't change. You're spending the same amount of energy either way.

I'd set it to 50% (which is what I do) and plug it in every day. This is also a better habit (IMO).

 

[zoomer0056]

Search for posts by @AAKEE and start reading. You'll learn a lot about battery degradation. You’ll learn how to care for your battery.

 

[jjrandorin]

Hello

i drive about 90 miles round trip for work.

I heard battery degradation is dependent on discharge cycles and state of charge. I typically keep the state of charge between 80% ( i drive 10-13% as soon as i get to 80) and 20% ( i charge as soon as i get close to 22%)

if I do frequent top ups to 50 or 60% , wouldn't the number of discharge cycles increase?

If you drive 90 real miles every day to work and back, there is zero chance that you would actually be able to "charge every 3 days". It isnt going to work like that, but you will find this out very quickly (or have already found this out if you have the car already).

People already addressed the charging cycle question, but just to reiterate, a cycle is 100-0, so whether you charge 10% of your capacity 10 times or run it from 100% to 0 once, its still one cycle. None of that is really going to matter much as far as what you are asking, though.

Your "90 mile round trip to work" drive is likely going to take somewhere between 90 and 125 "tesla miles" off the range, each time you do it, depending on a bunch of factors that you likely already know about. I say "already know about" because if you are asking a question about "charging cycles" it means you already have started going down the "battery degradation rabbit hole" of trying to get a ton of information on this topic.

The best you will do is charge every other day, not every 3 days, no matter what you do unless you dont drive to work every day.

 

[AAKEE]

if I do frequent top ups to 50 or 60% , wouldn't the number of discharge cycles increase?

The number of actual charge cycles (or the number of times you plug the car in) is not of importance.

When you see a chart about cycles, it is mostly expressed in FCE (full cycle Equivalents).
You need 10 cycles of 10% depth of discharge to use one FCE.

For the battery, small cycles are best.
Many bstteries can do 10.000 FCE of small 10% cycles, thats actually 100.000 small cycles.

Smaller cycles is better.
Cycles in general will only cause like one percent or less in cyclic aging each year. Most probably 0.5%. So no need to worry about that…

 

[father_of_6]

The best you will do is charge every other day, not every 3 days, no matter what you do unless you dont drive to work every day.

I don't understand. The Y can get a real-world range of 270, right?

 

[jcanoe]

With a 90 mile daily commute (round trip) you should charge every time you return home (unless you are able to charge at work.) If you are able to charge at your place of work, especially if it does not cost you to charge, they do that as often as you can.

Reasons to skip daily charging:
Working from home for a day, did not drive your usual commute
Weekends, may not use the Tesla Model Y except for local errands.

Now that we're heading into winter you should start to explore the Tesla charging settings for Scheduled Charging or Scheduled Departure - Charging and Scheduled Departure - Preconditioning. If you are charging at home, using Level 2 (240V) charging then it is more efficient to have charging complete shortly before your leave home and start driving on your commute.

You might want to set the daily charge limit from 80% down to 70% and then you would be charging, daily, from ~40% up to 70%. (Personally I would keep it at 80%. I regularly charge my 2020 LRMY above 80%, have done for over 3 years and see no reason to change now.)

 

[Venk Dakshin]

This is helpful. I didn't understand that charge discharge cycles is not every charging session but a full 0-100%

I can plug in quite often

 

[father_of_6]

This may be splitting hairs, but setting your daily charge to 50% and running it down to 20% (assuming you use 30% daily, which you have not stated) is healthier for the battery.

It may not make a major difference in the long run, but if you really want to baby the battery, set the daily charge as low as you can while still providing for your driving needs (and keeping the battery above 0%).

This may seem counterintuitive compared to what most people do with rechargeable electronics... we usually charge to full and use it until it's low, but that's not the best way to treat a lithium battery.

It also might feel "bad" getting near the bottom of the battery, almost like driving an ICE on fumes... but you get over that with experience.

 

[ATPMSD]

This may be splitting hairs, but setting your daily charge to 50% and running it down to 20% (assuming you use 30% daily, which you have not stated) is healthier for the battery.

Generally speaking for best longevity use the middle 50% of the battery. So charge to 80% and don't go below 20% regularly. And as noted previously, there are thousands of posts on subjects like this. So don’t stress about it, just do whatever makes you happy!

 

[jjrandorin]

I don't understand. The Y can get a real-world range of 270, right?

From 100% to 0 (depending on speed etc) but no one is charging to 100%, and driving it down to 0, to try to achieve that.

 

[jjrandorin]

From 100% to 0 (depending on speed etc) but no one is charging to 100%, and driving it down to 0, to try to achieve that.

I should have added the additional detail, that I am saying this as a person who has an 80 "real miles" commute to the office, which I have been driving to for the past 17+ years. I have been driving my model 3 on this commute since I got it in 2018, so this length of commute to work is something I am very familiar with, and as far as driving a Tesla on it is concerned, I have done that since Dec of 2018. My 80 real mile commute takes between 80 (ish) "Tesla miles" and 125 ish "Tesla miles" (off the range meter), with the worst range being in rain.

 

[father_of_6]

Makes sense. And in Winter climates the numbers are all worse.

 

[AAKEE]

Generally speaking for best longevity use the middle 50% of the battery. So charge to 80% and don't go below 20% regularly. And as noted previously, there are thousands of posts on subjects like this. So don’t stress about it, just do whatever makes you happy!

That statement wont give the lowest degradation, and it has no support in science either.
Below 20% is not bad.

 

[johnnycnote]

I suggest it is not worth your brain cells to worry about this. If you really care there are thousands of posts on this subject with a wide range of opinions.

Tesla’s “official” position is:

”The most important way to preserve the high voltage Battery is to LEAVE YOUR VEHICLE PLUGGED IN when you are not using it.” (page 172 of Model Y manual)

This. I plug in every day no matter what the state of charge is

 

[ATPMSD]

That statement wont give the lowest degradation, and it has no support in science either.
Below 20% is not bad.

There is in fact little support in science for most of what people have to say about Tesla batteries because there is no data on Tesla batteries. People are making statements based on general facts that are applicable to Lithium batteries, often based on laboratory tests. To my knowledge there is little real world data, and the Tesla Battery Management system not been factored in.

This is why we have thousands of posts - because there is in fact no definitive answers.