Which is better 80%-25% or 90% to 35% or something else for daily commute

[Chetanh]

So we live in the Great White North and my commute to work is a little over 100 miles. Add in trips to swimming, gymnastics, grocery etc and i typically end up using 55% of the battery daily. (SR+). I have access to 6KW charging at work which costs more or less the same as charging at home.

Given this scenario what levels should i ideally charge the vehicle
1) 80% in the morning and arrive home at 25% SOC before plugging it on.
2) 90% in the morning and arrive home at 35% SOC before plugging it on.
3) Charge to 70% at home and charge at work and then arrive home at approximately 40-50% SOC
4) Something else

Also, should i change this schedule depending on the season (winter, summer (i will use about 5-10%) less range in summer.

Based on current usage i will drive about 40,000kms a year (25,000 miles) and the battery warranty will expire in around 4 years and i want to keep the vehicle for around 10-12 years/400,000 kms (Kept most of my ICE cars around 350K) so am looking for a charging strategy to minimize battery degradation.

Thanks.

 

[linuxguyInMD]

Look for elon's twitter message, 80 - 30%. "Resetting" the range by driving over 90 and below 10% is interesting.

 

[SigNC]

IMO you'd be best charging to 90% with it finishing toward time to leave. That gives you more flexibility on running it low if something comes up where you need to use extra miles without having to run the battery low. You can probably adjust this back to 80 as it warms up. You could also just charge to 90% and not worry about it. The additional capacity retention will be basically nothing from charging everyday to 80 vs 90.

 

[SalisburySam]

Gee, the manual says to keep the car plugged in when available, and at delivery the agents say to feel free to charge to 90% mostly and 100% when you need to. What was the question again?

From p145 v36.1 of the manual: “The most important way to preserve the Battery is to LEAVE YOUR VEHICLE PLUGGED IN when you are not using it.”
Also from p145: “There is no advantage to waiting until the Battery’s level is low before charging. In fact, the Battery performs best when charged regularly.”

 

[PianoAl]

From p145 v36.1 of the manual: “The most important way to preserve the Battery is to LEAVE YOUR VEHICLE PLUGGED IN when you are not using it.”

I see that advice as well as the "A plugged in Tesla is a happy Tesla" quote.

Can someone explain why?

An example:

We rarely drive more than 30-60 miles in a day. Let's say the car is at 85%, and I drive 15 miles. When I come home, should I plug it in?

Thanks.

 

[mreynolds767]

Your mileage and charge numbers based on where you live seem optimistic at best for winter ; these are actual figures?
I have a similar commute and likewise 55-60% of the battery most every day BUT that is with a an AWD which should have much more range and I am in I assume warmer Boston area.
I lose much more range in the winter than you seem to, I know the AWD is not as efficient as the SR+ but still seems odd.
I don't have charging at work but your first two figures don't seem to account for charging while at work?

I typically charge to 80% most days but if below 33 F out, going to be very windy, stormy or know I have stops to make I go to 85% or 90%
Usually charge to at least to 80 right after I pull the car in for the night ; while the battery is still warm. Sometimes the last 5 or 10% I do in the morning right before I leave.

I have not yet charged to more than 90%; but rather go to 90% than return home with less than 20%.

Anyway to your numbers based on what you have provided I would go to 85% with the goal of returning home at 30% and in the warmer months go down to 80% for your nightly charge.

I drive about 30K miles per year and goal is to get 6 years out of the car for me so likewise will be out of warranty.

Not sure there is conclusive studies on this, the car is too new and any tests on the older model S batteries may not even be valid for the newer batteries Tesla now uses.

 

[planehazza]

I see that advice as well as the "A plugged in Tesla is a happy Tesla" quote.

Can someone explain why?

An example:

We rarely drive more than 30-60 miles in a day. Let's say the car is at 85%, and I drive 15 miles. When I come home, should I plug it in?

Thanks.

It won't really cost you more doing so, and it means that you can rely on Sentry mode etc without worrying about drain too much.

 

[SalisburySam]

I see that advice as well as the "A plugged in Tesla is a happy Tesla" quote.

Can someone explain why?

Maybe that the manufacturer says this is the best way to preserve the battery? Do you not believe the manual? Why the angst over following a pretty simple direction?

 

[Chetanh]

Your mileage and charge numbers based on where you live seem optimistic at best for winter ; these are actual figures?
I have a similar commute and likewise 55-60% of the battery most every day BUT that is with a an AWD which should have much more range and I am in I assume warmer Boston area.
I lose much more range in the winter than you seem to, I know the AWD is not as efficient as the SR+ but still seems odd.
I don't have charging at work but your first two figures don't seem to account for charging while at work?

I typically charge to 80% most days but if below 33 F out, going to be very windy, stormy or know I have stops to make I go to 85% or 90%
Usually charge to at least to 80 right after I pull the car in for the night ; while the battery is still warm. Sometimes the last 5 or 10% I do in the morning right before I leave.

I have not yet charged to more than 90%; but rather go to 90% than return home with less than 20%.

Anyway to your numbers based on what you have provided I would go to 85% with the goal of returning home at 30% and in the warmer months go down to 80% for your nightly charge.

I drive about 30K miles per year and goal is to get 6 years out of the car for me so likewise will be out of warranty.

Not sure there is conclusive studies on this, the car is too new and any tests on the older model S batteries may not even be valid for the newer batteries Tesla now uses.

I try to minnimize heating while driving (when alone).. Not because i wont get to my destination or something like that.. its just because i am crazy that way.. this may change over time though. (i turn the heat on then off then on and then off again a few times during my commute)
Between 10F and 30F i average between 220wh/mi to 290wh/mi. This is my commute. When i am out with wife and/or kids we average between 425 and 450Wh/mi.
Two main reasons for the differnce
1) With wife/ and kids its mostly city and frequent stop and go, heaters ON and heat set to 22C (71.6F)
2) With me alone the drive is mostly highhway with Autpilot set at 68mph (1 hour of continous driving very little or no traffic)

Yes, my first two figures dont seem to reflect charging at work because i dont charge at work (i have the option but have just charged a couple of times when i forgot to charge at home)

 

[Candleflame]

for OT: 80 - 25% is better than 90 - 35%. We know this because Elon has confirmed this particular question via Twitter though the long term effect is probably not particularly noticeable. Once you get below 20% you risk undervolting the battery slightly which will affect the lifespan though rumour has it that the Tesla Model 3 battery pack is so good that you do not get undervolting even at low percentages.
---

As to the question why a plugged in tesla is a happy tesla:

Two reasons:
1) The battery heating and interior heating can be run from the outlet directly and bypass the battery (anything running over the 12V has to run via the battery)
2) You cycle the battery less. I.e. 80% -> 78% and then charge up 10x to 80% is better than 80% - 60% and then charge up once.
In fact, a constant topping up of the battery by 1% probably will probably not affect battery life at all.

 

[ivan801]

After you (almost) run out of charge that one day when you have an unexpected side trip you will always charge to 90%.

 

[KenC]

So we live in the Great White North and my commute to work is a little over 100 miles. Add in trips to swimming, gymnastics, grocery etc and i typically end up using 55% of the battery daily. (SR+). I have access to 6KW charging at work which costs more or less the same as charging at home.

Given this scenario what levels should i ideally charge the vehicle
1) 80% in the morning and arrive home at 25% SOC before plugging it on.
2) 90% in the morning and arrive home at 35% SOC before plugging it on.
3) Charge to 70% at home and charge at work and then arrive home at approximately 40-50% SOC
4) Something else

Also, should i change this schedule depending on the season (winter, summer (i will use about 5-10%) less range in summer.

Based on current usage i will drive about 40,000kms a year (25,000 miles) and the battery warranty will expire in around 4 years and i want to keep the vehicle for around 10-12 years/400,000 kms (Kept most of my ICE cars around 350K) so am looking for a charging strategy to minimize battery degradation.

Thanks.

Since you want max longevity, then I would think 80-25 would be best, and adjust for Winter and extra side trips, by charging at work, when necessary.

 

[SigNC]

Maybe that the manufacturer says this is the best way to preserve the battery? Do you not believe the manual? Why the angst over following a pretty simple direction?

It's actually what the manufacturer says that is the best blend of ease of use and battery longevity. If a customer wants to take a more active approach to increase battery life, even if it's minimal, more power to them.