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. New to EV. MYLR.Except if you look at the graph you can see you lose about 0.75% per 15,000 miles using large cycles and much more than that per year by not using a low SOC strategy. Note the cycles were done continuously at 3C and who does that. In short, you gain more by low SOC than you lose by deep cycles.
For NMC cells (which I think you have in an MYLR) there really is no gain in storage degradation below 55% SOC at normal temperatures. Ok at 50C (122F) there is a benefit but you won’t hit that hopefully.
Personally I need 30% per day for my commute and I like to have a 25% buffer for unexpected work trips so I charge to 65% at work using schedule change to be ready when I leave. I’m at 50% overnight and at 20-35% when I get back to work depending on errands etc.
MYLR (MIC) 9m old 25,000kms 2% degradation according to Tessie.
I would be curious if anyone would advise better charging for battery life given my usage.
Personally I need 30% per day for my commute and I like to have a 25% buffer for unexpected work trips so I charge to 65% at work using schedule change to be ready when I leave. I’m at 50% overnight and at 20-35% when I get back to work depending on errands etc.
MYLR (MIC) 9m old 25,000kms 2% degradation according to Tessie.
I would be curious if anyone would advise better charging for battery life given my usage.
I'm saying one shouldn't charge to 100% without a good reason. It takes several hundred 100% depth of discharge cycles to degrade the battery to 80%, so you should spend those wisely. I personally plan on just calibrating one or two times a year and that's mostly it. Even for a road trip, going to 100% won't do anything for me as superchargers are closely spaced enough for me to do 80 to 20 percent easily. I did go up to 90% a couple of times when my hotel didn't have destination charging and I wanted to "fill up".
To me, good reasons are:
1. Battery calibration
2. Needing the range to get to the next charger
3. Away from easy charging for a bit
If one actually has good reason to charge to 100% daily, then an EV is probably not the right choice.
Did you watch Jeff Dahn's presentation? It's educational and should put a lot of your questions in the proper context.
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Where are you getting the info about charging yi 100 of you use it right away? Is that from a video you watched?
I don't understand your question. Maybe wait on the questions until you watch the video first?
I did’nt see this thread until now.
While it is true that smaller cycles most often cause less degradation in reality we are only looking at ~ 0.5% cyclic degradation or less during one year anyway.
The first 10 years calendar aging will cause degradation about 7 times more than cyclic aging.
The first year we have ~ 5% Calendar aging if charging to 80% and driving average ranges. Thats 20 times as much calendar aging as cyclic aging.
So, se can effectively forget about cyclic aging and only focus on the Calendar aging if we would like to minimize degradation.
My tip is to only try to minimize calendar aging, and as a end result cyclic aging also will be less.
As for the OP question I would not bother to charge lower than 50%. Already at 50% the regular total degradation is cut in half.
Many tests shows that the calendar aging is kind of the same between 30-55% for NCA chemistry, and about the same for NMC.
The reduction in calendar aging below ~30% is not very high so there will be a difference but it will be small.
The conclusion is that the battery need to stay most of the time well below 30% to make a difference and the difference will be small.
I always charge to 55% daily, as 30-55% makes no big change (50% would be enough for the daily drives).
When I leave the car for one week at work it is easy to plan to arrive there with ~10-20%, and I need to charge before going home anyway.
While it is true that smaller cycles most often cause less degradation in reality we are only looking at ~ 0.5% cyclic degradation or less during one year anyway.
The first 10 years calendar aging will cause degradation about 7 times more than cyclic aging.
The first year we have ~ 5% Calendar aging if charging to 80% and driving average ranges. Thats 20 times as much calendar aging as cyclic aging.
So, se can effectively forget about cyclic aging and only focus on the Calendar aging if we would like to minimize degradation.
My tip is to only try to minimize calendar aging, and as a end result cyclic aging also will be less.
As for the OP question I would not bother to charge lower than 50%. Already at 50% the regular total degradation is cut in half.
Many tests shows that the calendar aging is kind of the same between 30-55% for NCA chemistry, and about the same for NMC.
The reduction in calendar aging below ~30% is not very high so there will be a difference but it will be small.
The conclusion is that the battery need to stay most of the time well below 30% to make a difference and the difference will be small.
I always charge to 55% daily, as 30-55% makes no big change (50% would be enough for the daily drives).
When I leave the car for one week at work it is easy to plan to arrive there with ~10-20%, and I need to charge before going home anyway.
I don't believe this is true. Have you read any of @AAKEE 's stuff? Changing to 100% had about the same effect if you charge to 80%. Saying it's bad to charge to 100 is just a forum myth. If things broke when you changed to 100 Tesla wouldn't let you do it.
Cyclic aging is quite low anyway for most users.
The normal case is around 0.5% cyclic aging per year.
As calendar aging is about 5% the first year and 10% over the four first years for the average user, it is very safe to say that the largest reduction in degradation comes from calendar aging. Using low SOC will reduce the calendar aging by 50%.
It also naturaly reduces the possibillity to use large cycles so the cyclic aging will be reduced also.
The best SOC-wise area to cycle the Panasonic NCA cells is around 35-55%, thats where the same DoD wear the least.
To sum it up, calendar aging is what to mainly reduce. Doing this will also reduce cyclic aging.
Everything above from several research reports including real tests using real lithium ion cells.
There are practical problems with charging to below 50%
1) There is no autostop limit below 50% this means manual intervention
2) when you stop the charging 50%, the autostop limit remains at 50%
3) any re-setting / adjustments of scheduled departure or scheduled charging times will also restart charging.
Scenario:
You get home from work
Autostop limit 50%
You stop charging at 40%
You then adjust the time for scheduled departure and preheating for the next day.
Any adjustment of the scheduled departure or scheduled charging functions will automatically and immediately restart the charging.
So unless you stop the charging again , it will continue charging to 50%.
For me it's too much manual intervention
Jeff Dahn recommends that if DoD is less than 25% the battery health is maximised. So between 30-50% is perfect. There is no reason to do 60-80% if 30-50% gives all the range you need (of course some people may need more%)
1) There is no autostop limit below 50% this means manual intervention
2) when you stop the charging 50%, the autostop limit remains at 50%
3) any re-setting / adjustments of scheduled departure or scheduled charging times will also restart charging.
Scenario:
You get home from work
Autostop limit 50%
You stop charging at 40%
You then adjust the time for scheduled departure and preheating for the next day.
Any adjustment of the scheduled departure or scheduled charging functions will automatically and immediately restart the charging.
So unless you stop the charging again , it will continue charging to 50%.
For me it's too much manual intervention
Jeff Dahn recommends that if DoD is less than 25% the battery health is maximised. So between 30-50% is perfect. There is no reason to do 60-80% if 30-50% gives all the range you need (of course some people may need more%)
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You all inspired me to open up ABRP to figure out what my typical use would entail. Seems like I'm fine only charging to 60% for my daily driving. That should leave a buffer for winter heating and summer cabin conditioning along with enough for a short spontaneous trip. The 100% charging will be left for towing the camper.
Good discussion for us new owners!
Good discussion for us new owners!
I do not think there is anyone recommending to hit the charge below 50% for a Tesla. There are EV’s that even can be set down to 20% though.
The thing that causes the most degradation is calendar aging, and this is very flat below the strep change at 55% displayed SOC (NCA) and 60% (LG NMC(A) in model LR more or less all over the world now.
There is virtually no reduction in calendar aging between 30-55/60% so going lower does not really make any difference IRL.
NCA; a good average over many tests:
LG NMC M50; cell closely related to the LG M50-F cell in the cars:
Not very easy to read, but we can use this picture if we disregard the (badly executed try to connect the lines) and only look at the marked data points.
These datapoints match the rest of the NMC research results well.
Look at the piints at 60-30-10%, quite similar.
For the cyclic aging we can see for the Panasonic NCA that 10% depth of discharge cycles wear the least between 55-35% and 25-35 + 55-65% are in the middle of the chart. In all the cyclic wear will be so low annually that we actually can disregard it. But if we look into it anyway, se see that the regime below the step step in calendar aging is the area where the battery degrades the least from cyclic aging.
There has been a few forum members that still found the idea to charge really low appealing despite the data stating that it does’nt mather much. While is is doable the gain is probably not noticable but the effort etc. and the end result: having very short range is.
I charge to 55% since 3.5 years as 55% is the sweet spot between still same low degradation and maximized range.
50% would be enough for 99.5% of the days I use 55%, but it is a easy choice to always use the same and no need to think.
Even
My wife knows how to set it to 55% if it was set higher for a road trip etc.
So 55% for NCA and 60% for NMC maximizes the range while still at low degradation.
Charging higher, like 100% still does not cause any noticeable degradation when the charge is performed shortly before the drive.
My ‘23 MS Plaid still has 97 kWh (out of 99.4 full pack when new) where the most cars never go above 97-98kWh after 1 year and 21K km.
I charge full around 15 times a year and use ~ 20 sessions of SuC each year.
So the low SOC strategy works and the cars follows the charts from calemdar aging tests very well.
There is a part about low SOC and low SOC cycling that might need to be discussed. The degradation from Supecharging (lithium plating) can to a part be reverted by low SOC and low SOC cycling. So that will further reduce the degradation compared to always charging to 80% or so between the Supercharging sessions.
2024 MY LR AWD. I pick it up later this week. It'll be eventually charged on the Tesla wall connector once the electrician can make room in their schedule. For right now it'll be the mobile connector on 120v and fast charging/destination charging on longer trips. That will meet needs fine over the summer.
This thread was good reading on how much battery we really need day to day. Turns out that with an efficient vehicle driven efficiently it's doable for a good chunk of us even with slower charging.
I think the main thought is that that car has the panasonic NCA, despite the EPA test implies the same energy as the LG pack uaed in the model 3 LR, and all 3/Y LR/P in Europe.
If your car has the Panasonic NCA, try to stay at 55% or below. There is a probability that you more or less double the degradation above 55% displayed SOC.
So whenever 55% is do-able, use it instead.
If we learn about the exact battery later we might be able to ”allow” you to go up to 60% for daily then.
And 40% would be enough for 95% of the time for me. Unfortunately charging to limit below 50% requires manual intervention.
While there might be minimal difference between 40 and 50%, I would use 40% if auto charging limit allows 40%.
AAKEE - I've learned so much more about my battery from you since trading in my 2018 Model 3 LR AWD for a 2023 Model Y Performance last year. I felt the Model 3 battery degraded too much for me, because I normally kept it at 80% and often would charge to 100% for trips. Now, with my Model Y I keep it charged at 50% which I have discovered is fine for around town drives. For trips I go to 55% making sure my route has plenty of Superchargers. Surprisingly this seems to be working for me. Lately though my 9 month old Model Y hasn't been driven daily, sometimes it's weeks before I drive it. I have another vehicle that's kept outside and is just easier to access. If my Tesla every gets Summon again, then it will be easier to get in and out of my garage, I miss Summon. Anyway, am I doing things right keeping my Model Y plugged in at 50%, even though it's not driven much? I think I am but want to hear your thoughts.
While the question is for @AAKEE, here is my 0.05 cents worth:
Jeff Dahn says 30% is ideal for nickel containing batteries when storing the car especially in Summer.
The only problem is that you will need to manually charge the car to maintain 30%. If you don't use sentry and the car is asleep you maybe need to manually check once or twice a week to top up the charge to maintain 30%. Then when you need the car charge back to whatever is needed.
I once kept the car at 35% at the airport for a week. No sentry but I checked it online periodically after a week it was 33%.
50% is a lot easier as the car maintains itself at 50% when plugged in. If it were me I would rather do the 30%.
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