Charging strategy for battery longevity

[Paul73]

It appears from Battery University (lots of good pages), 3.92V per cell (approx 60%) is the best average "storage" level (possible jump in capacity loss above 60%)

As far as I've seen so far:
* Low soc increases internal resistance.
* High soc causes sudden capacity loss sooner (after a lower number of charge/discharge cycles).

So it appears for short trips, a daily topup back to 60% when you get home is probably best.

I plan to get the long-range Model 3, and usually stay between 30% and 70%, occasionally charge at home to 85% just before a very long trip, use the "full speed" superchargers as little as possible, 100% throttle sparingly, and avoid ever discharging below 20% (apparently gentle acceleration is best if below 30%?).

If for some reason the car won't be plugged in for many days, beware vampire drain (x% per day).

 

[TexasEV]

It appears from Battery University (lots of good pages), 3.92V per cell (approx 60%) is the best average "storage" level (possible jump in capacity loss above 60%)

As far as I've seen so far:
* Low soc increases internal resistance.
* High soc causes sudden capacity loss sooner (after a lower number of charge/discharge cycles).

So it appears for short trips, a daily topup back to 60% when you get home is probably best.

I plan to get the long-range Model 3, and usually stay between 30% and 70%, occasionally charge at home to 85% just before a very long trip, use the "full speed" superchargers as little as possible, 100% throttle sparingly, and avoid ever discharging below 20% (apparently gentle acceleration is best if below 30%?).

If for some reason the car won't be plugged in for many days, beware vampire drain (x% per day).

Or you could just ignore all this, enjoy the car, keep it set at 80 or 90% for daily use and charge to 100% just before trips, and let the battery management system manage the battery. Which is what tens of thousands of Tesla owners have done for the past 5 years with no more loss of range than those who obsess over the battery.

 

[mjgillen]

Or you could just ignore all this, enjoy the car, keep it set at 80 or 90% for daily use and charge to 100% just before trips, and let the battery management system manage the battery. Which is what tens of thousands of Tesla owners have done for the past 5 years with no more loss of range than those who obsess over the battery.

Obsessing is more fun

 

[ForeverFree]

Or you could just ignore all this, enjoy the car, keep it set at 80 or 90% for daily use and charge to 100% just before trips, and let the battery management system manage the battery. Which is what tens of thousands of Tesla owners have done for the past 5 years with no more loss of range than those who obsess over the battery.

One other thing to keep in mind for those of us who live here in The Land of the Natural Disaster: Power outages. Unlike hurricanes, earthquakes and wildfires do not come with advance warning ... and can leave power out for days.

An outage last fall prompted me to change our default charging percentage from 70% - 80% and move scheduled charging from dawn to evening (start of "base" rates). Not quite as good for the battery, but wise if we have an unexpected multi-day outage.

Now investigating Tesla solar + Powerwall ...

 

[timk225]

Just charge it up, run it to nearly dead, Charge it up, run it dead. Any problems? That's what the warranty is for. Besides, I've read Tesla battery stories over the years and they seem to do pretty well with not losing a lot of capacity even with a lot of supercharger usage.

 

[timreeser]

Just charge it up, run it to nearly dead, Charge it up, run it dead. Any problems? That's what the warranty is for. Besides, I've read Tesla battery stories over the years and they seem to do pretty well with not losing a lot of capacity even with a lot of supercharger usage.

The Tesla warranty does not cover degradation. Also note that very few Teslas have a lot of cycles --and many of the few that do have had their batteries replaced. Try finding a Tesla with 200k miles that hasn't had its battery replaced. Tesla's early adopters were largely CA drivers that didn't use it as a daily driver. My recommendation is to follow battery university and charge to 80-90, and never below 20.

 

[mblakele]

The Tesla warranty does not cover degradation

I believe that starting with the 3, for the first time, it does. Here's the language:

Your vehicle's Battery and Drive Unit are covered under this Battery and Drive Unit Limited Warranty for a period of:

• Vehicles with Standard Range Battery - 8 years or 100,000 miles (160,000 km), whichever comes rst, with minimum 70% retention of Battery capacity over the warranty period.
• Vehicles with Long Range Battery - 8 years or 120,000 miles (192,000 km), whichever comes rst, with minimum 70% retention of Battery capacity over the warranty period.

 

[goto10]

...which means they don't cover up to 30% of degradation. So until your 310 pack is charging to less than 217 miles any loss of range is your own problem.

 

[FlatSix911]

One other thing to keep in mind for those of us who live here in The Land of the Natural Disaster: Power outages. Unlike hurricanes, earthquakes and wildfires do not come with advance warning ... and can leave power out for days.

An outage last fall prompted me to change our default charging percentage from 70% - 80% and move scheduled charging from dawn to evening (start of "base" rates). Not quite as good for the battery, but wise if we have an unexpected multi-day outage.

Now investigating Tesla solar + Powerwall ...

Consider getting a 12V to 120V power inverter for emergencies.
You can power a few household appliances with a 750W inverter when connected to the 12V charging posts.
Should last a few days with recharging from the main battery in the car or until power is restored after a blackout.

 

[timreeser]

I believe that starting with the 3, for the first time, it does. Here's the language:

Your vehicle's Battery and Drive Unit are covered under this Battery and Drive Unit Limited Warranty for a period of:

• Vehicles with Standard Range Battery - 8 years or 100,000 miles (160,000 km), whichever comes rst, with minimum 70% retention of Battery capacity over the warranty period.
• Vehicles with Long Range Battery - 8 years or 120,000 miles (192,000 km), whichever comes rst, with minimum 70% retention of Battery capacity over the warranty period.

Great catch--I didn't realize this changed with the 3.

 

[aronth5]

Picked up my Model 3 last Friday in Dedham, Mass.
When I specifically asked the Delivery Specialist about charging he said that Tesla definitely recommends charging to 90%.
He made a point that the improved battery chemistry and battery management in the Model 3 was driving this recommendation.
Wondering what other people have been told?

 

[SigNC]

Picked up my Model 3 last Friday in Dedham, Mass.
When I specifically asked the Delivery Specialist about charging he said that Tesla definitely recommends charging to 90%.
He made a point that the improved battery chemistry and battery management in the Model 3 was driving this recommendation.
Wondering what other people have been told?

Even with a great BMS I would say only charge as high as you need with a buffer for whatever surprise might come up for the day. For me that's usually about 60% during the week.

 

[furizu]

Picked up my Model 3 last Friday in Dedham, Mass.
When I specifically asked the Delivery Specialist about charging he said that Tesla definitely recommends charging to 90%.
He made a point that the improved battery chemistry and battery management in the Model 3 was driving this recommendation.
Wondering what other people have been told?

i just picked up mine this week and he said the same thing to me. keep it 90% and plugged in all the time. I've been only using ~20% on my daily commute so wondering if i should throttle it down to 60% like others have said. hmm decisions decisions.

 

[aronth5]

So just to confuse matters more here is the charging recommendation from Tesla's own web site. Sure would be nice if they had one consistent message.
"Your Model 3 will automatically charge to the set limit whenever you plug in. We recommend setting your charge limit to meet your daily needs, and only charging beyond daily needs when going on a road trip."
View my Tesla Model S

And then there is Elon who says 80%
Elon Musk on Twitter

And then there is Jeff Dahn (Tesla Industrial Research Chair and Professor of Physics and Atmospheric Science at the University of Dalhousie)
"For those that don't wish to watch the video he recommends daily charging to 70 percent and to go ahead and charge to 100 percent for longer trips"
Jeff Dahn's recommendation on long term battery preservation

 

[TexasEV]

The point is that it doesn’t really matter if you routinely charge to 70%, 80%, or 90%. We have five years of data now with the Model S. It doesn’t make any practical difference in battery degradation. There may be a theoretical difference, but it’s of no practical importance.

 

[nrechtman]

Wouldn’t it be great if they had owner learning seminars at Tesla stores like Apple has “Today at Apple” learning sessions.

 

[aronth5]

The point is that it doesn’t really matter if you routinely charge to 70%, 80%, or 90%. We have five years of data now with the Model S. It doesn’t make any practical difference in battery degradation. There may be a theoretical difference, but it’s of no practical importance.

You may very well be right but for what its worth the Delivery Specialist specifically said one of the reasons to charge to 90% was due to the change in battery chemistry from the Model S/X to the 3.
Of course Delivery Specialists often don't offer the best information but my point was it would be nice if there was a consistent message. Do I expect that to happen, no but one can wish right?

 

[suwaneedad]

You may very well be right but for what its worth the Delivery Specialist specifically said one of the reasons to charge to 90% was due to the change in battery chemistry from the Model S/X to the 3.
Of course Delivery Specialists often don't offer the best information but my point was it would be nice if there was a consistent message. Do I expect that to happen, no but one can wish right?

I'll go with the owner's manual over a random delivery 'specialist' who may or may not have completed high school just yet. They're doing the best they can but some humans want to give an answer even when they should just say "I'm not sure. Let me get back to you."
The manual says 70%. Read it just today while waiting for my wife to come out of a store. So have taken my LEAF habit of 80% which I had extended to my Model 3, down to 70%. If the manual changes at some point, I will also.

 

[ratsbew]

What page of the manual does it say 70 percent?

 

[drawfour]

The manual says 70%. Read it just today while waiting for my wife to come out of a store. So have taken my LEAF habit of 80% which I had extended to my Model 3, down to 70%. If the manual changes at some point, I will also.

70% of 310 miles is as many miles as you'll get on a fully charged SR. So not bad.