The only Battery Answer you will ever need! [Personal Opinion]

[CertLive]

Again spouting stuffs without facts to back them.. you just join today and started this thread and is spreading false info...

I started this thread off after reading here for a few weeks and seeing so many people ask questions to which there are some fine technical answers but you can charge the model 3 just how you like without any worry at all. The battery and motor efficiency of the model 3 is at the point where battery degradation is nothing to worry about for the life of the car and that with the BMS software you do not need to worry about how much you charge it guided by the final 90% marker for daily and 100% for that long trip. This also keeps improving over time.

 

[Rocky_H]

Again proves there is no need to worry just go by the markers on the app for daily and travel @ 90% or 100% respectively

...which is really funny, as this very thing you are referencing is false. That is not a marker at 90% for Daily. It is not one single set point. Daily is marked as a range from 50% to 90%. Hmmmmm. Now why would they do that? The answer (supported by facts and data) is that using a state of charge a bit closer to the middle is slightly healthier for the battery long term, but they do want to let people know to keep it as high as they need to for their own personal practical usefulness of the car for how much driving range they need.

I find this kind of perspective you have borderline crazy, actually. If you accidentally have that slider just a touch too high, at 91%, the car will start to give you warnings after a few days of that, that it is not healthy for the battery, and you should stop doing that, because it is in the "Trips" area and should only be used occasionally. But then you go around finger-wagging and trying to shame people who try to use anything lower than 90% because you say that it is a magical boundary between 90% and 91%, where 90% is the most perfect thing ever, and is the best thing to use, etc. etc. That makes no sense at all.

 

[CertLive]

...which is really funny, as this very thing you are referencing is false. That is not a marker at 90% for Daily. It is not one single set point. Daily is marked as a range from 50% to 90%. Hmmmmm. Now why would they do that? The answer (supported by facts and data) is that using a state of charge a bit closer to the middle is slightly healthier for the battery long term, but they do want to let people know to keep it as high as they need to for their own personal practical usefulness of the car for how much driving range they need.

I find this kind of perspective you have borderline crazy, actually. If you accidentally have that slider just a touch too high, at 91%, the car will start to give you warnings after a few days of that, that it is not healthy for the battery, and you should stop doing that, because it is in the "Trips" area and should only be used occasionally. But then you go around finger-wagging and trying to shame people who try to use anything lower than 90% because you say that it is a magical boundary between 90% and 91%, where 90% is the most perfect thing ever, and is the best thing to use, etc. etc. That makes no sense at all.

Finger wagging.... oh I have not heard that term from my great grandma in a while but she only made it to 89. Lets see you are right but I never said 91% I said 90%. Yes you can also use 50% if you like but anything in that range is good and you know what they even add a little notch so you have to finger wag a little harder than normal to push it over the line. Up to 90% of your slice of the battery pie is just fine.

 

[Cheburashka]

I usually charge my 2016 to 50-60% on a 120V wall plug since I don't drive very often.

Battery degradation is no better or worse than those that charge to 90% every day. I have just over 40K miles now.

 

[Rocky_H]

Lets see you are right but I never said 91% I said 90%.

It's like you didn't even try to read what I wrote. I never claimed you said that. Here it is:

If you accidentally have that slider just a touch too high, at 91%, the car will start to give you warnings after a few days of that,

That was my example, where I pointed out that if someone hypothetically does use 91%, the car warns you against doing that. (I guess I should have used the word "someone" instead of the generalized word "you".) So your telling people to use something a single percent less than what Tesla advises against does not make sense. It was a contrast to point out that there isn't some magical boundary between "bad" and "good" that happens to exist between 90 and 91%. There is a continual spectrum of the farther you can get away from the extreme high end, the better, but for simplicity's sake, Tesla just generalized that into two categories.

 

[CertLive]

I usually charge my 2016 to 50-60% on a 120V wall plug since I don't drive very often.

Battery degradation is no better or worse than those that charge to 90% every day. I have just over 40K miles now.

Exactly yes we all have our different chargers and speeds but unless the BMS kicks in and says nope lets take it down a bit Tesla have this system well dialled in miles better than anything I have seen from the other manufacturer's at the moment. That is why I just think it is no longer a factor to be worried about.

 

[Rocky_H]

That is why I just think it is no longer a factor to be worried about.

And that's why there is no "worrying". It is just doing what is a little easier on a piece of equipment or a product that doesn't impact our usage of the product. That's not specific to an electric car or anything else. It could be a piece of clothing or an appliance or whatever. If you don't need to be hard on it, don't.

 

[CertLive]

It's like you didn't even try to read what I wrote. I never claimed you said that. Here it is:


That was my example, where I pointed out that if someone hypothetically does use 91%, the car warns you against doing that. (I guess I should have used the word "someone" instead of the generalized word "you".) So your telling people to use something a single percent less than what Tesla advises against does not make sense. It was a contrast to point out that there isn't some magical boundary between "bad" and "good" that happens to exist between 90 and 91%. There is a continual spectrum of the farther you can get away from the extreme high end, the better, but for simplicity's sake, Tesla just generalized that into two categories.

Again that is for the BMS to manage. You know in the UK its quite cold so 6 to -2 and even on the app now I could have set that 90% yesterday but now its really 89% because the gates are being dynamically moved and within the tolerance Tesla feel is good for their cars with years of experience on this now. They still tweak all the way to the first car battery packs. At the moment the buck stops at 90% and that is proving to be just fine. Really is some sweet Tesla science behind this.

 

[CertLive]

And that's why there is no "worrying". It is just doing what is a little easier on a piece of equipment or a product that doesn't impact our usage of the product. That's not specific to an electric car or anything else. It could be a piece of clothing or an appliance or whatever. If you don't need to be hard on it, don't.

Oh I agree with you on this and I am just saying there is really no difference in the 60% or 90% because they are both in the safe area because its a slice not the total battery capacity.

 

[TMThree]

So ask the guy who reached 100,000 miles and excessively supercharged and got 2.5% loss. "Musk said that they built Model 3 to last as long as a commercial truck, a million miles, and the battery modules should last between 300,000 miles and 500,000 miles."

If you even average that out for 95% of people who buy one why exactly are you even the slightest bit worried on the soc or what speed you charge it? Graphs show one thing, real world usage in the hands of the consumer show another and yes I am focusing on the Model 3 as an owner and as it uses the most advanced system that is at this worry free point.

Again proves there is no need to worry just go by the markers on the app for daily and travel @ 90% or 100% respectively as you never do charge it 100% to damage it. The cars software will not allow it.

You should take a class or two in statistics. Then look up how distribution curves work. Or, if you're so sure about this one example, maybe you should start up a warranty service for Tesla model 3 owners and put your money where your mouth is.

You would make millions very quickly if your thesis is correct. Imagine it:

"I CertLive, will offer a new battery guarantee for all Model 3 owners for a one time payment of just $1500. You can charge your car to 90% daily, and supercharge the crap out of it. I don't care! I'll buy you a replacement battery if it drops more than 3% in 100,000 miles."

Heck, I might even take you up on it.

PS: Did you see the guys who are on the wrong end of the curve? Those people exist too.

 

[CertLive]

You should take a class or two in statistics. Then look up how distribution curves work. Or, if you're so sure about this one example, maybe you should start up a warranty service for Tesla model 3 owners and put your money where your mouth is.

You would make millions very quickly if your thesis is correct. Imagine it:

"I CertLive, will offer a new battery guarantee for all Model 3 owners for a one time payment of just $1500. You can charge your car to 90% daily, and supercharge the crap out of it. I don't care! I'll buy you a replacement battery if it drops more than 3% in 100,000 miles."

Heck, I might even take you up on it.

PS: Did you see the guys who are on the wrong end of the curve? Those people exist too.

Well thanks for the business idea but I am doing just fine in my profession. However 3% is not very much in 100,000 miles in terms of a battery pack if you have been hammering it. By then you either still trust the car to get you to your destinations or you buy something else but that is quite normal. Should we start comparisons with the gradual decline in horse power / range of an ICE engine over time plus replacement parts? Because that is the only reality to compare it to. There is no competition with the motor or power system on the Tesla right now. A car Tesla built in 2012 the model S still beats all other sporty electric car offerings today on efficiency and they all lose battery over time. I have a warranty thanks that covers the battery for 8 years too so....

Reality check there is no need to worry about the battery unless there is a significant failure. Charge it how you damn well like depending on the situation fast or slow you cant charge it more than the BMS wants your too as it is the battery God

 

[rowdy]

Reality check there is no need to worry about the battery unless there is a significant failure.

That used to be the case. Now there isn't a significant failure in most situations. The BMS will detect you've charged 90% too often and tesla will simply cripple your charge speeds and take 10%+ of your range to avoid the failure.

 

[tga]

You never have 100% of your battery only 100% of your slice, this BMS manages the stress levels without worry to the user.

This is flat wrong; you can't get enough disagrees on this one. Stop posting opinions as facts. Unless you are one of the unlucky few subject to charge capping/"batterygate", a 100% state of charge is, indeed 100%, 4.2V. It's easy to see from CAN bus data.

And why do you keep going on about Model 3 batteries in an S subforum?

 

[CertLive]

This is flat wrong; you can't get enough disagrees on this one. Stop posting opinions as facts. Unless you are one of the unlucky few subject to charge capping/"batterygate", a 100% state of charge is, indeed 100%, 4.2V. It's easy to see from CAN bus data.

And why do you keep going on about Model 3 batteries in an S subforum?

Charge capping is the BMS doing its job for the battery state and age depending on how you treat it. More so on older models from what I have read but that is to protect its longevity no? As I understand it owners of model 3,s this year have improved batteries and this will continue onto the next cars and so on with better design. So indeed you can keep charging it as you wish and the car will take care of the cells so you get the most use possible. So thus no real worry set it as you wish. I don't think you get 100% of the cells unless you deliberately run it down past the 0% reserve.

 

[tga]

Charge capping is the BMS doing its job for the battery state and age depending on how you treat it.

Wrong. No one knows why charge capping is happening. It may be a manufacturing defect in the cells, it may be how the battery was treated/used. No one knows.

So indeed you can keep charging it as you wish and the car will take care of the cells so you get the most use possible. So thus no real worry set it as you wish.

That logic only applies to new (Raven) S's, not older ones.

I don't think you get 100% of the cells unless you deliberately run it down past the 0% reserve.

The total range of capacity used is irrelevant. Cells are stressed at either end of the range (below 20% or above 90%). The battery is not damaged from running from 100% to 0%. The damage occurs for charging to 100% and for discharging to 0%. They are independent events. There is a bottom buffer ("anti-bricking" protection) that prevents you from going all the way to 0%, but no such protection at the upper end (unlike other manufactures, which limit both).

 

[CertLive]

but no such protection at the upper end (unlike other manufactures, which limit both).

Is there any documentation for the above? I was quite sure no EV,s not even Tesla allowed the total top end as a small buffer. When 100% is selected on the app it is really 98 ish of the total battery's capacity I would expect.

I think its information overload, Tesla could have just given us no charge limit on the app and you just fill as long as you leave it plugged in up to the BMS allowed limits. With the options Full / Read to much and am now paranoid about my cells (translates to 90%)

 

[tga]

Is there any documentation for the above?

Documentation for what, (a) "but no such protection at the upper end" or (b) "unlike other manufactures, which limit both"? (A) is easily demonstrated by checking cell voltages after a charge to 100% with a CANbus scanner. Full charge on an 18650 cell is 4.2V. An uncapped Tesla pack at 100% charges the cells to 4.2V. If there was an unusable top buffer, 100% indicated would be something like 4.15V @ 100%, but it's not. For (B), you'll have to check other manufacturers documentation or forums. But, for example, it's known that Volt has a top and bottom buffer. I forget the exact amounts reserved at either end.

 

[CertLive]

Documentation for what, (a) "but no such protection at the upper end" or (b) "unlike other manufactures, which limit both"? (A) is easily demonstrated by checking cell voltages after a charge to 100% with a CANbus scanner. Full charge on an 18650 cell is 4.2V. An uncapped Tesla pack at 100% charges the cells to 4.2V. If there was an unusable top buffer, 100% indicated would be something like 4.15V @ 100%, but it's not. For (B), you'll have to check other manufacturers documentation or forums. But, for example, it's known that Volt has a top and bottom buffer. I forget the exact amounts reserved at either end.

Ok so 90% + gives you significant slowdown in charge because it is slowing to the true 100% limit. That means 90% or less is perfectly fine for every day charge when you like. So there is no need to worry setting it at 90% and charge it whenever. But 100% is 100% topped up all cells.

 

[tga]

Ok so 90% + gives you significant slowdown in charge because it is slowing to the true 100% limit. That means 90% or less is perfectly fine for every day charge when you like. So there is no need to worry setting it at 90% and charge it whenever. But 100% is 100% topped up all cells.

Correct. I've been in the habit of charging to 70% for my day-to-day, because I don't use more than 30% on most days. But I will easily admit that I'm just being anal, and any difference between that and charging to 90% is probably negligible.

EDIT - I charged to 89% today. After a 15 min rest, cell voltages were 4.086/4.089/4.092 (min/avg/max). 18650 voltages range from 3.2V @ 0% to 4.2V @ 100%. State of charge vs voltage isn't linear, but 4.1V ~= 90% on an 18650, in line with my observations.

 

[Rocky_H]

Ok so 90% + gives you significant slowdown in charge because it is slowing to the true 100% limit. That means 90% or less is perfectly fine for every day charge when you like. So there is no need to worry setting it at 90% and charge it whenever. But 100% is 100% topped up all cells.

It's not magically perfect at 90%. The effect is on a gradual scaling spectrum that is a bit exponential. 90% is better than 100%, but 80% is better than 90%, etc., etc.