Is it okay to charge to 100% if I am immediately going to use it right away?

[sleepydoc]

This is the source, near as I can tell.

BU-808: How to Prolong Lithium-based Batteries

BU meta description needed...

batteryuniversity.com

Thank you for the source. I'll have to read the entire article more carefully, but of note, shortly after the graph in question was presented they presented the following graph that compares battery degradation that appears to show significantly higher degradation with higher charges. Even this chart doesn't explicitly state what a 'cycle' is. Classically, it is defined as a full charge -discharge cycle (i.e. 0-100%-0%) but this chart appears to compare a 50% subtotal discharge cycle vs a 60% and 75% discharge cycle. If this is the case the 100-25% curve represents 50% more energy use than the 75-25% curve. Even taking that into account you see more than twice the degradation with the 100-25% cycle.

The article also explicitly says that real world results are always worse than laboratory tests.

Fundamentally, the consistent message for maximizing battery life from the sources I've seen is:

• Avoid charging extremes.
• Avoid rapid discharging and rapid charging.
• Avoid temperature extremes
• Don't let the battery sit completely charged or completely discharged.

I'd also note that I forgot to reset my charge limit after I set to 95% for a trip and got a warning message on my display to reduce the charge limit to maximize the battery life.

 

[sleepydoc]

Ok - I read through the entire article referenced above. It was actually quite interesting. Since it's more of a general battery info article, I posted it here:
Another charging battery life thread

 

[Marty3SR+]

Hopefully I didn't miss any comments about this, but don't forget that you lose some efficiency (and maybe driving pleasure) charging to 100% due to no regeneration.

 

[Rocky_H]

Hopefully I didn't miss any comments about this, but don't forget that you lose some efficiency (and maybe driving pleasure) charging to 100% due to no regeneration.

People say that, and it is technically true, but only lasts for a few minutes, and by then, you have used up some energy, and regeneration is coming back. So it just doesn't amount to much of anything to be a noticeable level of efficiency loss.

 

[Bourne]

Fwiw, have a ‘16 S 85D now on its 6th year.. 71K miles(waiting patiently for a MYLR).. charged to 90 every plug in except for trips where it went 100 and drove within 24 hrs.. at home rarely drops below 60-65%.. on freeways I let it come down to 5%… original 270 range.. current max charge 266-67.. dropped to 264 last year with a patch but went up again

 

[AAKEE]

The normal way to express cycles in research is [FCE = Full Equivalent Cycles].

A Full charge from 0% to 100% and a discharge back to 0% is one FCE.

Charging and discharging from 0-50% needs two charge cycles to reach one FCE.

10% dept of discharge cycles needs 10 cycles to reach one FCE.

FCE make the comparison much easier for us, becuse it relates to the driven miles in our cars. The charging achedule that causes least wear per FCE is the one that degrade our battery least per mile driven.

A graph that shows charge/discharge cycles need to be interpreted correctly to be usefull.

Also, I think this thread is missing information about calendar aging, as it is the dominant battery degrading factor during the first five years or so.

 

[AAKEE]

Here is a chart you can refer too which plots various SOC ranges against battery degration. This is from a laboratory battery test and not a test of a Tesla battery.

View attachment 753532

About the discussion of how the cycles is counted, if it is each charging cycle or per FCE.
It need to be presented in FCE to be useful for us. In the graph it looks like [Full Equivalent Cycles] as smaller cycles should reduce the degradation per energy delivered / FCE.

If the graph would show per actual discharge/charge cycle, at the point at 3000 cycles:

75-65 lost 5%, that is 5% per 300FCE, or 1% per 60 FCE

75-25 lost 10% that is 10% per 1500FCE or 1% per 150FCE

100-25% = 17.5% thats 17.5% per 2250FCE or 1% per 132 FCE.

This does not look correct at all. Smaller cycles should cause less wear per FCE.

I would say that the graph need to show per FCE, otherwise the results contradicts most(all) otjer research.

Here is the
Source for the picture

I did a brief look to try to find a reference for FCE or ”per avtual cycle” but I did not find it. I did read this report a few years back. There are some issues with the test setup that could make people draw the wrong conclusions so I will not use much time try to find the answer, as I rather would say ”read other research reports instead”.

 

[peternarbus]

Here is a chart you can refer too which plots various SOC ranges against battery degration. This is from a laboratory battery test and not a test of a Tesla battery.

View attachment 753532

Is the for the NCA Battery?

 

[ZenRockGarden]

If you're going to use it right away and have the time, sure charge to 100%.

The thing the batteries dislike is sitting for extended time at max (or min).

 

[AAKEE]

The thing the batteries dislike is sitting for extended time at max (or min).

That is not correct. That is forum myths.

Below is the real fact. This is how batteries wear from different SOC.

The blue line show degradation at normal temperatures after sitting for ten months.
What is very clear is that low SOC do not cause any stress and that 0% even cause the lowest degradation from time.
Its also clear that at normal temperatures or colder 100% SOC cause about the same degradation as 70-80-90%. There even is several research reports that show that 80-90% is worse than 100%.

If you're going to use it right away and have the time, sure charge to 100%.

As we can see above, there is no need to drive immediatly. Even at higher temperatures the increased degradation is only slightly more than at normal temperatures. For example 100% at 40C is causing about the double degradation compared to 80% at normal temperatures ehich means that one hour at 100% and 40C wear as two hours at 80% and normal temps. No rush really needed.

Despite the above, as there is no need to leave the car at 100% I would not recommend to do it so one could plan to drive when the charge is finished.
On the other hand, if a reason arises, you do not need to be stressed about driving asap.

 

[ZenRockGarden]

That is not correct. That is forum myths.

Below is the real fact. This is how batteries wear from different SOC.

The blue line show degradation at normal temperatures after sitting for ten months.
What is very clear is that low SOC do not cause any stress and that 0% even cause the lowest degradation from time.
Its also clear that at normal temperatures or colder 100% SOC cause about the same degradation as 70-80-90%. There even is several research reports that show that 80-90% is worse than 100%.
View attachment 875766




As we can see above, there is no need to drive immediatly. Even at higher temperatures the increased degradation is only slightly more than at normal temperatures. For example 100% at 40C is causing about the double degradation compared to 80% at normal temperatures ehich means that one hour at 100% and 40C wear as two hours at 80% and normal temps. No rush really needed.

Despite the above, as there is no need to leave the car at 100% I would not recommend to do it so one could plan to drive when the charge is finished.
On the other hand, if a reason arises, you do not need to be stressed about driving asap.

You made the mistaken assumption that the only thing to care about is capacity degredation.

Try running your actual tesla pack (not a lab cell) down to 0% and then store it that way a few days. Write back after the experience

 

[AAKEE]

Is the for the NCA Battery?

No it is not.

Its a total different kind of battery.

There is also not good to present the result like that in single cycles. You can not draw any valuable conclusions without calculating the life in FCE (full cycle equivalent) or the total energy for each tested SOC region.

Also, no lower SOC region was really used so it is har to do any good conclusions.

The best is to disregard that picture.
A bit of this is explained here.

 

[AAKEE]

You made the mistaken assumption that the only thing to care about is capacity degredation.

Try running your actual tesla pack (not a lab cell) down to 0% and then store it that way a few days. Write back after the experience

Driving down to zero is not a problem. There is 4.5% buffer below. The HV battery disconnects after reacing the minimum voltage and is protected because of this for a reasonable time. If the car is left long enough with too low voltage and the HV battery disconnects the LV lead acid 12V battery WILL get damaged as these degrade as soon as they reach lower charging status. Because of this, and that you get stranded it is not recommended (just as the Tesla manual states) to leave the car at very low SOC like 1 or 0% for extended time. But this has nothing to do with that it would be dangerous for the expensive HV battery.

store it that way a few days. Write back after the experience

I will not do it, for obvoius reasons

Anyway, most probable, it would not be a problem at all. As there is a good amount of energy and my car use less than 1% per week parked a few days would not be enough to shut down the battery.
I have driven down to both -1.8 and -2% (data from Scan My Tesla as the display only show 0%) without any problems, I only left the car for an hour and a half to let is sleep at low SOC then I charged Again.

This is what we are discussing here:

The thing the batteries dislike is sitting for extended time at max (or min).

This is the thread topic:

Is it okay to charge to 100% if I am immediately going to use it right away?​

 

[ZenRockGarden]

If the car is left long enough with too low voltage and the HV battery disconnects the LV lead acid 12V battery WILL get damaged as these degrade as soon as they reach lower charging status. Because of this, and that you get stranded it is not recommended (just as the Tesla manual states) to leave the car at very low SOC like 1 or 0% for extended time.

It would have been simpler to just say "Yeah, you're right, these cars do NOT like to sit at 0% which is the only thing you said"

 

[AAKEE]

It would have been simpler to just say "Yeah, you're right, these cars do NOT like to sit at 0% which is the only thing you said"

To keep myths alive?

 

[ZenRockGarden]

To keep myths alive?

I never said 0% causes battery degredation - you made that up.

I said these cars do not like to sit at 100% (and 0%) This is not a myth - as you yourself admitted it's literally in the owners manual.

 

[AAKEE]

I never said 0% causes battery degredation - you made that up.

I said these cars do not like to sit at 100% (and 0%) This is not a myth - as you yourself admitted it's literally in the owners manual.

Show me where in the manual it says that they do not like to sit at 0% (except that Tesla say charge asap to not risk damage to other components like the LV battery)

Also, show me where the manual says the car do not like to sit at 100% ?

Its not written in the manual. That is a myth.
People fill in myths between the written lines.

This post show why Tesla tell us to use max 90% for the daily driving. The post itself is about low SOC cycling but the data show that reducing the SOC from 100 to 90% reduce the cyclic aging by about 30%.

 

[Hiline]

That is not correct. That is forum myths.

Below is the real fact. This is how batteries wear from different SOC.

The blue line show degradation at normal temperatures after sitting for ten months.
What is very clear is that low SOC do not cause any stress and that 0% even cause the lowest degradation from time.
Its also clear that at normal temperatures or colder 100% SOC cause about the same degradation as 70-80-90%. There even is several research reports that show that 80-90% is worse than 100%.
View attachment 875766




As we can see above, there is no need to drive immediatly. Even at higher temperatures the increased degradation is only slightly more than at normal temperatures. For example 100% at 40C is causing about the double degradation compared to 80% at normal temperatures ehich means that one hour at 100% and 40C wear as two hours at 80% and normal temps. No rush really needed.

Despite the above, as there is no need to leave the car at 100% I would not recommend to do it so one could plan to drive when the charge is finished.
On the other hand, if a reason arises, you do not need to be stressed about driving asap.

So the cutoff is right around 50%-60%, but this is for leaving the battery inactive for 10 months straight. Not sure how things would look for daily storage Fascinating info regardless. Appreciate your digging through the research!

 

[ZenRockGarden]

Show me where in the manual it says that they do not like to sit at 0% (except that Tesla say charge asap to not risk damage to other components like the LV battery)

Also, show me where the manual says the car do not like to sit at 100% ?

Its not written in the manual. That is a myth.
People fill in myths between the written lines.

This post show why Tesla tell us to use max 90% for the daily driving. The post itself is about low SOC cycling but the data show that reducing the SOC from 100 to 90% reduce the cyclic aging by about 30%.

Let me literally quote YOU on the subject of leaving the car at 0%: "Because of this, and that you get stranded it is not recommended (just as the Tesla manual states) to leave the car at very low SOC like 1 or 0% for extended time"

Are you now going to argue with yourself about it? My statement was simply that the cars don't like to sit long term at either 100% or 0%. This is simply TRUE. I made no claim whatsoever about WHY. You want to have a pissing contest about a non-existent claim that 0% causes degradation of the cells which no one on this thread ever made, including me.

 

[AAKEE]

So the cutoff is right around 50%-60%, but this is for leaving the battery inactive for 10 months straight. Not sure how things would look for daily storage Fascinating info regardless. Appreciate your digging through the research!

In these tests the batteries is not left insctice for ten months. They leave the batteries for a few months, cycle and measure the capacity and then charge them back to the actual SOC.

I get your point though.

If you drive an average range each year like 15K km or 10k miles, that’ll take about 300 hours. If you charge with 10kW, it would take another 300 hours. Thats 600 hours of “use”, the rest of the time (8160hours or 93% of the time) the car is either sleeping or use Sentry which is very low power. The car is parked for most of the year and the battery is at rest.

Besides this, calendar aging happens when it is in use also. So for a car that spends all time above the 60% mark, the calendar aging will be like the part above. If all time spent below 60% it will look like that. If you have a mix of above and below, the calendar aging will also be a mix. At least this is how the researchers look at it.