What should my ideal charge percentage be?

[Fiver]

In general more frequent, but shallower charges towards the middle of the pack (from 35-55% daily) are better than less often but larger charge sessions (30-75% every three days). Really though it's, in the grand scheme of things not going to really make that huge of a difference. Just keep it below 90% unless you need the range. Letting the car sit for long periods of time (days) with high state of charge is worse.

This is speaking mostly about battery wear though, and says nothing about what other people mention regarding wear on the cooling pumps and what-not that also are active when charging. So there's that to think about... (Low and slow vs high power but quickly finished)

 

[meomyo]

so....50-60% daily and just keep plugged in at home should be good no?

 

[tesluv108]

Charged again today , Tessie is still saying no degradation which is weird. I need to ask them if they are basing the no degradation rating on rated range or actual health of battery

 

[zoomer0056]

Charged again today , Tessie is still saying no degradation which is weird. I need to ask them if they are basing the no degradation rating on rated range or actual health of battery View attachment 866377

Sweet!!!! Tessie responds very quickly to inquiries.

 

[Arctic_White]

I get that we're all trying to maximize our battery shelf life, but studies performed by the owner of the Tesla "Stats" app said that it doesn't matter at what % you charge to, as long as you're not charging beyond 90% and dropping the SoC to under 10%.

Keep it plugged in at 70%, 80%, or 90% whatever you fancy, and don't worry about it.

I always charge to 90%, daily, and use b/w 10% and 30% of battery everyday.

My Plaid has lost just 1% of range in one year and 14K miles.

Unless you're supercharging your car daily, I wouldn't sweat it. Your battery will outlive the life of the car.

 

[aerodyne]

I get that we're all trying to maximize our battery shelf life, but studies performed by the owner of the Tesla "Stats" app said that it doesn't matter at what % you charge to, as long as you're not charging beyond 90% and dropping the SoC to under 10%.

Keep it plugged in at 70%, 80%, or 90% whatever you fancy, and don't worry about it.

I always charge to 90%, daily, and use b/w 10% and 30% of battery everyday.

My Plaid has lost just 1% of range in one year and 14K miles.

Unless you're supercharging your car daily, I wouldn't sweat it. Your battery will outlive the life of the car.

This is most likely true. However, I will add another useless anecdotal data point, that by storing the car at 55% over the last 2 years, I seem to have lost 3 or so less miles of rated range than my peers on Teslafi.

 

[dark cloud]

I get that we're all trying to maximize our battery shelf life, but studies performed by the owner of the Tesla "Stats" app said that it doesn't matter at what % you charge to,........

Well no, historically it hasn't mattered, because up until now the main reason the packs that have failed were not because of the cells losing capacity from non-optimal charging conditions, but mostly due to the electronic components getting fried due to moisture issues.

Your battery will outlive the life of the car.

This is not happening currently; only time will tell whether the current packs will last longer than ~8 years (or 240,000 km, whichever comes first)

 

[Arctic_White]

This is most likely true. However, I will add another useless anecdotal data point, that by storing the car at 55% over the last 2 years, I seem to have lost 3 or so less miles of rated range than my peers on Teslafi.

Yup.

Anecdotally, you and I both could've just had a slightly "better" battery too.

Too many variables here.

Point is to charge it every night to whatever % you feel right (b/w 70% to 90%) and try to not go down to less than 10%. Supercharge infrequently or when you're on trips.

Do NOT let the car stay at 100% and stored. That one is the key here.

Pre-condition the car as often as you can as a warm battery is a healthy battery during winter. And cooled battery is a healthy battery during summer.

 

[Arctic_White]

Well no, historically it hasn't mattered, because up until now the main reason the packs that have failed were not because of the cells losing capacity from non-optimal charging conditions, but mostly due to the electronic components getting fried due to moisture issues.




This is not happening currently; only time will tell whether the current packs will last longer than ~8 years (or 240,000 km, whichever comes first)

I wonder if Tesla made any changes since the 2015 model year to rectify said moisture issues?

Let's hope so and let's find it out together. I have faith that the battery itself will easily outlast my car ('21 Plaid). But I plan on selling mine once the Cybrertruck arrives LOL.

 

[aerodyne]

I wonder if Tesla made any changes since the 2015 model year to rectify said moisture issues?

Let's hope so and let's find it out together. I have faith that the battery itself will easily outlast my car ('21 Plaid). But I plan on selling mine once the Cybrertruck arrives LOL.

Actually, this has been discussed, and as far as the AC drain hose, that has been improved. See enclosed pic of my June 9 2015 build:

 

[Dave EV]

In general more frequent, but shallower charges towards the middle of the pack (from 35-55% daily) are better than less often but larger charge sessions (30-75% every three days). Really though it's, in the grand scheme of things not going to really make that huge of a difference. Just keep it below 90% unless you need the range. Letting the car sit for long periods of time (days) with high state of charge is worse.

Keep in mind also, that combining high temperatures and high SOC is the worst - high SOC at low temperatures can be tolerated quite a bit more than high SOC at high temperatures.

I get that we're all trying to maximize our battery shelf life, but studies performed by the owner of the Tesla "Stats" app said that it doesn't matter at what % you charge to, as long as you're not charging beyond 90% and dropping the SoC to under 10%.

All research indicates that low SOC is better for the battery in terms of rate of capacity loss than higher - even below 10%. Keeping charge cycles as shallow as possible is also important. Of course, this has to be balanced with usability...

I always charge to 90%, daily, and use b/w 10% and 30% of battery everyday.

My Plaid has lost just 1% of range in one year and 14K miles.

This has more to do with the fact that you live in Alberta, Canada than your charging habits. It's 20C cooler up there than most others - that usually results in about 4x lower rates of capacity loss, all else being equal thanks to Arrhenius' equation.

Pre-condition the car as often as you can as a warm battery is a healthy battery during winter. And cooled battery is a healthy battery during summer.

Way too simplistic, here, and depends on your definition of "healthy".

Tesla will "passively warm" the battery to 86F / 30C in normal driving and L2 - this means that it will move heat around to get the battery to 30C when driving and L2 charging. The active cooling target is something like 55C, so unless the pack is seriously baking, it doesn't direct AC to cool the pack.

Tesla does this not necessarily because this minimizes capacity loss, but it improves efficiency of the battery - you can charge and discharge the pack better that way. If the battery is too cold, that does limit the rate you can charge the pack without affecting rate of capacity loss, primarily due to an effect called lithium plating - that is the primary reason that Tesla heats the pack when cold - and also because a warmer pack is more efficient - you can also pull more power from the pack with less voltage drop when it's warm.

 

[Arctic_White]

Keep in mind also, that combining high temperatures and high SOC is the worst - high SOC at low temperatures can be tolerated quite a bit more than high SOC at high temperatures.


All research indicates that low SOC is better for the battery in terms of rate of capacity loss than higher - even below 10%. Keeping charge cycles as shallow as possible is also important. Of course, this has to be balanced with usability...


This has more to do with the fact that you live in Alberta, Canada than your charging habits. It's 20C cooler up there than most others - that usually results in about 4x lower rates of capacity loss, all else being equal thanks to Arrhenius' equation.


Way too simplistic, here, and depends on your definition of "healthy".

Tesla will "passively warm" the battery to 86F / 30C in normal driving and L2 - this means that it will move heat around to get the battery to 30C when driving and L2 charging. The active cooling target is something like 55C, so unless the pack is seriously baking, it doesn't direct AC to cool the pack.

Tesla does this not necessarily because this minimizes capacity loss, but it improves efficiency of the battery - you can charge and discharge the pack better that way. If the battery is too cold, that does limit the rate you can charge the pack without affecting rate of capacity loss, primarily due to an effect called lithium plating - that is the primary reason that Tesla heats the pack when cold - and also because a warmer pack is more efficient - you can also pull more power from the pack with less voltage drop when it's warm.

Research may indicate that low SoC is better for battery in terms of capacity loss but Tesla's own battery loss is not as severe as other batteries thanks to their Battery Management System/Software.

As I said earlier and will repeat: it does not matter at what % you charge at as long as it remains under 90%. Folks are taking this too literally and your posts, while trying to ber helpful, is not being helpful in determining the charge and helping ease owners mind that it really doesn't matter.

Too many of you are overthinking this. Just charge every night if possible and be happy.

 

[Dave EV]

Research may indicate that low SoC is better for battery in terms of capacity loss but Tesla's own battery loss is not as severe as other batteries thanks to their Battery Management System/Software.

No, it's actually the chemistry Tesla uses that has the biggest effect. BMS/software has little to nothing to do with it and even active thermal management does not have a large effect, except in hot climates or when doing lots of DC charging.

I had one of the first Nissan LEAFs, notorious for the rate of capacity loss and geeked out on how to minimize the rate of capacity loss while monitoring SOC and battery pack temperatures.

Despite the lack of active thermal management, pack temps rarely climbed significantly over ambient except when DC charging - and because of the limited range, you typically didn't do this all that often. Monitoring cell voltages, Nissan was far more conservative than Tesla - Nissan limited the pack to 4.1 V / cell at 100% where Tesla is only 90% there. Cell to cell balance was maintained just as well as Tesla.

And thanks to thermal management, Tesla actually tends to run the pack hotter than the LEAFs pack in my climate since it will actively direct heat from the onboard charger when L2 charging and heat from the motors to the battery when driving.

Despite this, my LEAF lost 30% capacity after about 5 years despite charging to 80% daily and rarely DC charging. My Model 3 is around 4.5 years old now and no where near that, but probably down 10% or so. For sure, in this comparison, the Tesla sees much fewer cycles of the battery since it's bigger - that helps, too, but with most capacity loss data for Tesla's, the rate of capacity loss tracks better with the age of the pack, than miles.

As I said earlier and will repeat: it does not matter at what % you charge at as long as it remains under 90%. Folks are taking this too literally and your posts, while trying to ber helpful, is not being helpful in determining the charge and helping ease owners mind that it really doesn't matter.

You are wrong. Maybe in your climate up there in freezing Edmonton it doesn't matter much, but for most people, it does and there's plenty of actual studies to prove it.

Too many of you are overthinking this. Just charge every night if possible and be happy.

Sure - just charge to the lowest SOC that you need on a daily basis.

 

[2101Guy]

There is also less stored energy in the pack in case of fire due to accident if you charge to only what you need each day.

 

[meomyo]

what about the range save toggle switch...on or off?

 

[Fiver]

what about the range save toggle switch...on or off?

Range mode off unless you are in a pinch on the road already.

 

[Rqcg]

You are wrong. Maybe in your climate up there in freezing Edmonton it doesn't matter much, but for most people, it does and there's plenty of actual studies to prove it.

Can you share the studies you base your conclusions on?

 

[Dave EV]

Can you share the studies you base your conclusions on?

It's well known that that calendar aging is the biggest component of capacity loss in most EVs and the rate of capacity loss is directly driven by temperature.

Have a look at @AAKEE 's post history, he has posted lots of data on this topic.

Low temperatures, low SOC and shallow cycles are the best way to minimize the rate of capacity loss.

 

[SO16]

For my Jan 2017 MS 90D in Michigan with over 90k miles, it originally could get 294 when new. Now it gets 272 at 100%. Degradation happened quickest during the first couple years and has since tapered off.

I stored it in winters for the first 4 years and left it plugged in at 50% in a non heated garage and charged to 80% when driving it for daily use. Now I drive it year around and charge to 80%. I have supercharged around 60 times and have charged to 100% when on road trips (Nova Scotia, Maine, WY, MT, CO, GA, Michigan UP, etc) which account for about 20k of the total miles. I have driven to 1 % a couple times and < 4% a handful of times. Supercharging still works at normal speeds.

I only use the Tesla app.

I could get by with 50% daily use but I prefer a buffer in case I need to go farther away last minute or a power outage, etc.

I just drive it and don’t fret about the 1-2% capacity difference I could have retained by doing “X”.

 

[Rqcg]

It's well known that that calendar aging is the biggest component of capacity loss in most EVs and the rate of capacity loss is directly driven by temperature.

Have a look at @AAKEE 's post history, he has posted lots of data on this topic.

Low temperatures, low SOC and shallow cycles are the best way to minimize the rate of capacity loss.

There are general effects based on thermodynamic laws but after a quick glance on his post and other knowledgable sources there is no direct correlation of degradation and SOC between 50-90%. I agree with the poster you replied too that these comments have to be taken with nuance.