Battery health tracking SS

[msinfo]

Learning about Tesla battery health, degradation and such from AAKEE and other knowledgable forum members I put together a quick SS to track battery stats for my MYLR 3/23 and to see how they change over time. I know there are apps that will do the same/more out there but personally I just don't care enough to pay for subscription.

I left my data in the SS if anyone cares and did not clean up any calculations I've used while learning. Of course feel free to d/l, clear the data, reuse it and make what ever changes you want. Hope it helps

PS My MYLR by now has 3841 miles with daily drive of about 2-20 miles up/down the ski hill and few monthly round trips of about 440 miles long. I keep my car plugged in and charge to 50% unless going for a trip (trip charge is typically 70-90% mostly depending on if I am planning on pulling the trailer). When on 220 miles trips I make one 10-20 minutes stop to rest and L3 charge to have about 30% battery estimate for arrival. I know 30% estimate is super conservative but it works for me so I don't have to pay attention to speed, getting rained/snowed while driving and when pulling trailer with my garden tractor couple times a year.

 

[ewoodrick]

50,000 miles, I charge my battery to 80% or 90% and 100% as I want to. I'll leave it at 100% for hours, even a day.
Over 5 years and still getting about 94% of initial range.

I do tend to charge to 100% a few times a year, mostly as I take trips.

Tesla designed the battery to be used and abused. They didn't design it to only charge to 50%.

And for me, 30% means that I need to find another stop further away. At 30%, you will barely see the advantage of a 250kW V3 charger, maybe just a minute or two before the rate drops below 150kW.

 

[msinfo]

That is really good to know that there are batteries with such a low degradation after 50K and consistent high SOC. From the statistics I've seen on this forum and elsewhere I think you've got really lucky and your battery do much better than average. Congrats! As for your comments about my 30% for the trip arrival I do it b/c it works and convenient to me. I only need one stop and frankly I need a stop on a four hour trip. I am no longer 20, 30, 40 or even 50 ... And for 50% daily if there was an option for 40% I would be doing that. I don't need more for my daily trips. Also, I feel better knowing I am minimizing battery degradation whatever that number will be.

 

[msinfo]

50,000 miles, I charge my battery to 80% or 90% and 100% as I want to. I'll leave it at 100% for hours, even a day.
Over 5 years and still getting about 94% of initial range.

I do tend to charge to 100% a few times a year, mostly as I take trips.

Tesla designed the battery to be used and abused. They didn't design it to only charge to 50%.

And for me, 30% means that I need to find another stop further away. At 30%, you will barely see the advantage of a 250kW V3 charger, maybe just a minute or two before the rate drops below 150kW.

FYI I plugged in your 94% of range and assuming current M3LR numbers/same battery pack as MYLR in calc and came out with about 9.5% battery degradation.

 

[flixden]

@msinfo --- I have a spreadsheet very similar to yours, but my results suck compared to yours.
I am charging only to 50% on a regular basis, and SC use is 11%.
@AAKEE , does this make any sense?

Seems like a pretty steep degradation.

BTW: the Wh/mile is high for the 5 miles and 15 mile averages, as most of the data was collected at home, and we have a 3 mile uphill stretch to get to our house.

 

[msinfo]

@msinfo --- I have a spreadsheet very similar to yours, but my results suck compared to yours.
I am charging only to 50% on a regular basis, and SC use is 11%.
@AAKEE , does this make any sense?

Seems like a pretty steep degradation.

BTW: the Wh/mile is high for the 5 miles and 15 mile averages, as most of the data was collected at home, and we have a 3 mile uphill stretch to get to our house.

View attachment 970662

Why do you say your numbers are bad? The battery capacity is on par. Yeah, the numbers do jump a bit same as I have but that to be expected with % numbers rounded and BMS approximations. If you want you can get more accurate % numbers from service mode. Personally, I would not jump to any degradation conclusion based on above and the time sample given. If you graph out the averages it looks almost flat.

PS Few days ago AAKEE explained to me that Tesla use a few kWh buffer (79-82.1) so it only makes sense that we begin to see averages stating to trend down once we are over the 79kWh hump.

 

[AAKEE]

50,000 miles, I charge my battery to 80% or 90% and 100% as I want to. I'll leave it at 100% for hours, even a day.
Over 5 years and still getting about 94% of initial range.

I do tend to charge to 100% a few times a year, mostly as I take trips.

Tesla designed the battery to be used and abused. They didn't design it to only charge to 50%.

And for me, 30% means that I need to find another stop further away. At 30%, you will barely see the advantage of a 250kW V3 charger, maybe just a minute or two before the rate drops below 150kW.

Model 3?

Would you mind take photo of the energy screen, showing average, calculated range and also the SOC in percebt at the battery and putting the picture in a post?

 

[AAKEE]

50,000 miles, I charge my battery to 80% or 90% and 100% as I want to. I'll leave it at 100% for hours, even a day.
Over 5 years and still getting about 94% of initial range.

I do tend to charge to 100% a few times a year, mostly as I take trips.

I have your car at 67,3kWh capacity After five years at mostly charging to 80% (I do not know the usual Depth of discharge but from total miles over five years I can do a good guess about the most common cycles). Also, the average annual is about 15C (59.1F or so), so the average cell temp most probably was at around 20C.

So you're at about 13% degradation. For a number of reasons I state that Your battery will be around this number.

Suggest you take a picture of the energy screen, also showin the SOC number in the same picture and post it here. (Energy screen setting in the lower right should be "normal range").

Tesla designed the battery to be used and abused. They didn't design it to only charge to 50%.

Panasonic built the battery cells, and they could not overcome the law of cphysics/chemistries so the battery cells will behave like they have to, by the laws of nature.

Tesla did not built it to be abused. They built the battery to be able to be charged daily to any SOC below 90% (which means 50-90%). Recently they changed that 90% number to 80%.

 

[AAKEE]

That is really good to know that there are batteries with such a low degradation after 50K and consistent high SOC. From the statistics I've seen on this forum and elsewhere I think you've got really lucky and your battery do much better than average.

Battery degradation is to a very high extent predictable and the variations in the research, both for calendar and cyclic aging tests, is quite small.

 

[AAKEE]

@msinfo --- I have a spreadsheet very similar to yours, but my results suck compared to yours.
I am charging only to 50% on a regular basis, and SC use is 11%.
@AAKEE , does this make any sense?

Seems like a pretty steep degradation.

BTW: the Wh/mile is high for the 5 miles and 15 mile averages, as most of the data was collected at home, and we have a 3 mile uphill stretch to get to our house.

View attachment 970662

I havent looked at the numbers more then a glance.

Looks like a very new car. Manufacturing date, is it only a few month old?

Until the car has gotten some age, the degradation threshold (around 79kWh?) will limit the correct view of things. You need Scan my Tesla to see it correct this early.
Charging low, like having 30-50% and calculating the maximum range will give you flawed numbers as the SOC is rounded to whole numbers.

Calendar aging is very steep the first months and then it lessens. If you have 5% calendar aging the first year you will get 2% the first two months. (square root fomula).

Relax, and remember that the "battery lottery" is a myth to the very most extent. You will be fine.

 

[outdoors]

50,000 miles, I charge my battery to 80% or 90% and 100% as I want to. I'll leave it at 100% for hours, even a day.
Over 5 years and still getting about 94% of initial range.

I do tend to charge to 100% a few times a year, mostly as I take trips.

Tesla designed the battery to be used and abused. They didn't design it to only charge to 50%.

And for me, 30% means that I need to find another stop further away. At 30%, you will barely see the advantage of a 250kW V3 charger, maybe just a minute or two before the rate drops below 150kW.

It is kind of getting old seeing folks say charge to 50% because they "know" they are minimizing degradation.

What a great way to stop furthering sustainable transportation. If I saw this thread and others from @AAKEE I would have laughed my way out of buying multiple Tesla's and would have never become an EV advocate.

Charge your car and only use a tiny bit of the battery as one could degrade it. Sounds like a great way to sell ICE cars.

So everyone here likes experiments. Go tell someone that is considering EV's this little exercise to save your battery forever and ever.
Then when done. Ask them if you can drive them to take a demo ride and buy a Tesla. More than likely they will stick with ICE.

Battery university is old news. Stick with Tesla. Drive ones car.

250k 11% degradation charge to 90 like all the time. At least 40 or 50 100% charges.

My 3 is fine as well. Oh wait. I am an outlier.

 

[flixden]

It is kind of getting old seeing folks say charge to 50% because they "know" they are minimizing degradation.

What a great way to stop furthering sustainable transportation. If I saw this thread and others from @AAKEE I would have laughed my way out of buying multiple Tesla's and would have never become an EV advocate.

Charge your car and only use a tiny bit of the battery as one could degrade it. Sounds like a great way to sell ICE cars.

So everyone here likes experiments. Go tell someone that is considering EV's this little exercise to save your battery forever and ever.
Then when done. Ask them if you can drive them to take a demo ride and buy a Tesla. More than likely they will stick with ICE.

Battery university is old news. Stick with Tesla. Drive ones car.

250k 11% degradation charge to 90 like all the time. At least 40 or 50 100% charges.

My 3 is fine as well. Oh wait. I am an outlier.

Some people like to analyze and do experiments like this. It's fun for them, almost like a hobby. And that's fine. We are all different ....

 

[AAKEE]

Some people like to analyze and do experiments like this. It's fun for them, almost like a hobby. And that's fine. We are all different ....

And when Model 3’s closing in to 10 years, we might have some cars with very tired batteries. It will not be the low SOC cars…

Some cars probably no one would like to touch with a pliers. This will not be the low SOC cars.

 

[outdoors]

Some people like to analyze and do experiments like this. It's fun for them, almost like a hobby. And that's fine. We are all different ....

Agreed, however we need to keep those people hidden. They don't help the situation. They muddy the waters, and have thoughts that don't translate to reality.

Battery university can't explain why I have 11% degradation and someone else has 20%. Most here point and say I am an outlier and the others are doing something wrong.

Which is not scientific in any meaningful way. Just old charts thrown up on an Internet forum.

 

[outdoors]

And when Model 3’s closing in to 10 years, we might have some cars with very tired batteries. It will not be the low SOC cars…

Guess mine aren't so tired. Who wants to buy ones car after 10 years? Find me a ten year old car that you have owned and sold.

Keep the car. Drive it. Have fun. Don't be a watt weenie.

Have one seen trade in values for Model 3?
2018 with 70k in miles are being offered 12-14k.

All that measurements to what get 15k from the buyer. Hey potential buyer, I only charged my car from 30 to 50% for the last decade. I want you to give me extra money for it because it is supreme and awesome battery that was babied for the last decade.

 

[flixden]

Agreed, however we need to keep those people hidden. They don't help the situation.

Why would people's opinions have to be hidden? I don't think I agree with you. What's the situation here that needs help?

I have the feeling that this will be getting off topic quickly, not sure I want to continue down that path.

 

[outdoors]

Why would people's opinions have to be hidden? I don't think I agree with you. What's the situation here that needs help?

I have the feeling that this will be getting off topic quickly, not sure I want to continue down that path.

It's just the same tired argument again and again and it doesn't help people use their cars. It helps people have their cars in a garage with a cover over them.

These ideas also do not promote sustainable transportation because it makes potential owners the view that this is a problem with batteries and that batteries aren't as good as gas cars.

So my view and my view alone is that I don't like when people come out with ideas that they don't really know are true. It's just promoting disinformation via old old information.

's aren't for everyone.

 

[AAKEE]

Battery university can't explain why I have 11% degradation and someone else has 20%. Most here point and say I am an outlier and the others are doing something wrong.

I guess we’re all fre to make our pwn choises about how to take care of the car.

Battery university have some flaws and faults on their site.

But I can explain and probably even predict the most probable degradation that your car has.

This is what I need:

You tell me what Tesla you have. Model/year and:
-Location/average temp:
-Manufacturing month or purchase month
-Do you have a garage or is it parked outside?
-Charging level.
-What SOC (charging level) do you have after a normal day.
-When do you charge? Daily (?), at what time does it start.
-Odo reading.
-lifetime average consumption.

What we should check it against is a energy screen calc, as it is commung straight from the BMS Capacity numbers.

 

[zoomer0056]

Hey potential buyer, I only charged my car from 30 to 50% for the last decade. I want you to give me extra money

The battery degredation is the end result that will decide the car's value.

 

[outdoors]

The battery degredation is the end result that will decide the car's value.

No actually the buyer determines the value. The one that hands the check over to you. The battery doesn't determine what someone else is willing to pay for your car.

Might be a factor, but you are deciding it's the most important factor. Not the buyer.