Charging everyday?

[ralph142]

Not what the experience so far has been on a Model 3. Keeping the car high in the 90%s for a long time - bad for the battery. Pluging it in and always charging from 60%-80%, sure way to trip your BMS and having shorter range.



But we can demonstrate the opposite (just read the forum) that following your advice is a sure thing to trip the BMS and have lesser range.

This is always the advice from Tesla, when people complain that they get less rated range when they charge to 100% and find less rated range displayed - small incremental charges from 60%-80% each day might help the battery, but if the BMS thinks you have less capacity that will not help you much. Also you are keeping the battery in the high % all the time which is def. not good for the battery itself.

Keeping the battery charged between 30%-90%, meaning let it go to 30%, plug in, let it go to 90%, but so that it reaches 90% when you can drive away (in the morning) and plug it in as soon as it reaches 30% seems like the best advice so far.

I don't think we "know" much at all, a lot of anecdotal stories, with little context or history. my experience runs counter to this advice. tesla surely has the data and can analyze it.

 

[davewill]

I’d like to park an ev over an inductive charger every night and never think about what’s best for some part inside the car or if I’ve got enough range if my drive plan changes. Now that’s what I mean about not fussing.

Perfect. You can do that right now, as long as you want to shell out for the inductive charger.

Well, as soon as somebody updates it for the Model 3, anyway: Meet Plugless | The Wireless EV Charging Station

 

[TimothyHW3]

My M3 has been great, no issues following Tesla's charging advice at all.

I don't think we "know" much at all, a lot of anecdotal stories, with little context or history. my experience runs counter to this advice. tesla surely has the data and can analyze it.

Well, we don't really "know", but if it quacks like a duck?

Just read the posts here
Mid-range changes in range or battery degradation
or here
https://teslamotorsclub.com/tmc/threads/model-3-performance-battery-degradation-one-month-story.129885/

or any of those posts about degradation. It is usually people charging from 70%-90% and never or very rarely deep discharging or charging to 100%. It really seems like the BMS on Model 3 doesn't like that.

 

[davewill]

...
But we can demonstrate the opposite (just read the forum) that following your advice is a sure thing to trip the BMS and have lesser range.
...

Even then, the only thing we know is that the onscreen DISPLAY of the range is lower. There's nothing to suggest that the battery itself is holding any less energy. In other words, no harm to the battery and no need for folks to fuss.

 

[TIppy]

Tesla considered inductive charging, but found the additional charging losses too large.

 

[nwdiver]

Keeping the battery charged between 30%-90%, meaning let it go to 30%, plug in, let it go to 90%, but so that it reaches 90% when you can drive away (in the morning) and plug it in as soon as it reaches 30% seems like the best advice so far.

Where have you seen cycle testing results that show that kind of use is better for the battery? Everything I've seen shows that charging everyday is FAR... FAAAR better for longevity than letting SOC get down to 30% before charging. Smaller cycles are going to result in a longer lasting battery.

 

[TimothyHW3]

Where have you seen cycle testing results that show that kind of use is better for the battery? Everything I've seen shows that charging everyday is FAR... FAAAR better for longevity than letting SOC get down to 30% before charging. Smaller cycles are going to result in a longer lasting battery.

You do understand that there are two things to consider - battery and BMS?
A BMS is a very complicated matter - you can't juse read the capacity of a battery - is hard chemical stuff that has to take in a lot of variables. Tesla are good, but even Tesla have limitations obviously. Something in the Model 3 outline and BMS doesn't seem to like small charges.
And you can have the greatest battery in the world, 0% degradation, if your BMS thinks you only hold 10% of charge, you can have 0 degradation and still be able to drive 25 miles... This is something people don't quite seem to understand.

Example:
If your ICE car has a bad fuel gauge and the car is set to shutdown if it shows you have 0 gas left, even though the motor can run and it is pumping in fuel (not how ICE cars work, but just an illustration on roughly how EVs batteries work) you can have all the gas in the world and the car will still shutdown.

It is not how much kWh you have - it is how much kWh the car THINKS you have!

Even then, the only thing we know is that the onscreen DISPLAY of the range is lower. There's nothing to suggest that the battery itself is holding any less energy. In other words, no harm to the battery and no need for folks to fuss.

No, this is not true. The onscreen "DISPLAY" is just a representation of what the car's BMS thinks you have. Read above. If the BMS is tricked, you are screwed...

Tesla CAN reset the BMS- someone mentioned it here, but once you start toping in 70-90% the BMS gets screwed again and you are off to another meeting with Tesla, if they care (which they don't evident by that same driver in this forum)!

How long until Tesla starts charging people to reset the BMS every other week if they just top up from 70-90%?!

The evidence is there, if you guys wanna ignore it, fine with me.

I am charging the way I suggested from 20-30 to 80 or 90% and have proven 1.3% (from full when new, actual range degradation is just 0.02%) degradation over 15,000km so far, with almost 60% fast charging above 150kW, but also very slow AC charging of 3kW after the long runs to balance out the battery.

 

[Rocky_H]

And you can have the greatest battery in the world, 0% degradation, if your BMS thinks you only hold 10% of charge, you can have 0 degradation and still be able to drive 25 miles... This is something people don't quite seem to understand.

No, this is not true. The onscreen "DISPLAY" is just a representation of what the car's BMS thinks you have. Read above. If the BMS is tricked, you are screwed...

Don't believe so. You seem to think that if the BMS has an artificially low estimate at the upper end, that it will stick with ticking that down linearly, numerically, and shut off at the point it had calculated at the beginning. Hence your comments about being "screwed" or only being able to drive 25 miles.

But it has been demonstrated that it continually monitors the energy it can detect, and if it is getting lower and finding that the voltage is still high and there is more energy in there than it originally thought when it was full, it will allow you to keep using a bit and reassessing what it will show on the display at the lower end.

 

[nwdiver]

You do understand that there are two things to consider - battery and BMS?
A BMS is a very complicated matter - you can't juse read the capacity of a battery - is hard chemical stuff that has to take in a lot of variables. Tesla are good, but even Tesla have limitations obviously. Something in the Model 3 outline and BMS doesn't seem to like small charges.
And you can have the greatest battery in the world, 0% degradation, if your BMS thinks you only hold 10% of charge, you can have 0

..... you're not going to be off by ~90%.... the BMS can be calibrated... that drift isn't permanent.... degradation is.

If you cycle 90 - 30 - 90 once a week instead of 90 - 78 - 90 daily you might have better indication of capacity for a few years but you'll end up with a battery with significantly lower REAL capacity that cannot be fixed with calibration... only replacement

Charging often is the best way to maintain a healthy battery because physics.

 

[TimothyHW3]

Don't believe so. You seem to think that if the BMS has an artificially low estimate at the upper end, that it will stick with ticking that down linearly, numerically, and shut off at the point it had calculated at the beginning. Hence your comments about being "screwed" or only being able to drive 25 miles.

I never said anything about linearly or 25 miles - the 25 miles were just an illustration of the principle of how BMS works. I don't think any BMS on a Tesla will ever read only 6-7kWh available when there are 75kWh in reality. But it will read 67kWh if it has 75kWh like it was on Like Tesla and like it has been reported here multiple, multiple times.

But on the rarest occasion that it does read only 6kWh, yes the car will shutdown. And this is just the basicst of facts. There are hundreds of examples of the cars shutting down even though it shows 5% or more.

Here is an older Bjorn Nyland video, where his car shutdown with 15km left apperantly. And there were about 4kWh left as a buffer below those 15km. So he actually was supposed to have 40km left, but the car shutdown, because the BMS was tricked.

 

[TimothyHW3]

..... you're not going to be off by ~90%.... the BMS can be calibrated... that drift isn't permanent.... degradation is.

Can be calibrated? How? Is this why we are getting thousands of thousands of posts about people "loosing range"?
Charging from 10-100? forget it - people have tried that multiple times and doesn't fix the BMS.

The only thing that helped so far is a trip to Tesla for them to reset the BMS (watch that Like Tesla video or read the links I posted). I bet after 1 trip they will A) ignore you B) charge you 200$

If you cycle 90 - 30 - 90 once a week instead of 90 - 78 - 90 daily you might have better indication of capacity for a few years but you'll end up with a battery with significantly lower REAL capacity that cannot be fixed with calibration... only replacement

I don't cycle 30-90. I try to cycle 30-40%-80%, but I also try to go to 10% and then back to 90% at least once a month, maybe even more.

90% on a Model 3 is about 85% real so 90%, unless you idle for long and drive right away, will be fine for the battery

My proven degradation is at 0.02% at the moment (1.5% from actualy 77kWh new) and my BMS seems fine, showing 498 out of 499km, not like most folsk that charge 70-90% here.

I think I am doing pretty fine after almost a year and 10,000 miles...There is a fine line between keeping the BMS AND Battery healthy and I think the line is in that range, but def. not at 70%-90%. Besides, most people that charge 70-90% plug it in at 6pm and the car sits at 90% from 9pm until the morning. Bad for the battery, because physics.

Charging often is the best way to maintain a healthy battery because physics.

And the best way to screw your BMS, because Tesla...

 

[nwdiver]

And the best way to screw your BMS, because Tesla...

Only if you consider a temporary <10% 'loss' 'screwed'. I'll take that over permanent degradation.

 

[TimothyHW3]

Only if you consider a temporary <10% 'loss' 'screwed'. I'll take that over permanent degradation.

Again, temporary? How? Do you have a proven reset procedure that has actually worked in regaining 10%, besides going to Tesla?

And again, degradation?! How is charging to 90% every night and keeping the battery at 90% for almost 12 hours good for the battery as opposed to charging to 80% and driving right away, like I do?

 

[nwdiver]

Again, temporary? How? Do you have a proven reset procedure that has actually worked in regaining 10%, besides going to Tesla?

And again, degradation?! How is charging to 90% every night and keeping the battery at 90% for almost 12 hours good for the battery as opposed to charging to 80% and driving right away, like I do?

..... didn't you post a video showing the BMS being corrected? The only way to fix a degraded pack is to replaced it. Lots of ways to 'fix' BMS. I usually get ~5 or more miles of range back when I travel. That won't happen with a degraded pack.

Sure.... 80 - 68 - 80 would be better than 90 - 78 - 90 but only marginally. 90 - 78 - 90 x 5 is still going to be better than 90 - 30 - 90 once.

 

[TimothyHW3]

..... didn't you post a video showing the BMS being corrected?

No, and as far as I can see there is no other fix besides going to Tesla. I have seen numerous posts of people and videos where the only resolution is a reset from Tesla. All the 10-100% down to 10% and again didn't do anything good. It seems the Model 3's BMS is a different kind of beast.

Sure.... 80 - 68 - 80 would be better than 90 - 78 - 90 but only marginally. 90 - 78 - 90 x 5 is still going to be better than 90 - 30 - 90 once.

Nope. Can't be further from the truth. Model 3 doesn't have a top buffer, or at least not much, and at 90% you are sitting on the battery at around 4.15V where the optimal, according to experts smarter than you and me, is at 3.92V or around 65% on a Model 3.

So no, actually charging daily from 70-90% and letting the car sit at 4.15V all night day in and day out, especially in high temperatures like in California, is a sure way to a very, very, very high degradation.
Which is also evident by a lot of the posts here...

But don't let me stop you from doing what you think you should do, please report back at 50,000 miles!

 

[nwdiver]

No, and as far as I can see there is no other fix besides going to Tesla. I have seen numerous posts of people and videos where the only resolution is a reset from Tesla. All the 10-100% down to 10% and again didn't do anything good. It seems the Model 3's BMS is a different kind of beast.


Nope. Can't be further from the truth. Model 3 doesn't have a top buffer, or at least not much, and at 90% you are sitting on the battery at around 4.15V where the optimal, according to experts smarter than you and me, is at 3.92V or around 65% on a Model 3.

So no, actually charging daily from 70-90% and letting the car sit at 4.15V all night day in and day out, especially in high temperatures like in California, is a sure way to a very, very, very high degradation.
Which is also evident by a lot of the posts here...

But don't let me stop you from doing what you think you should do, please report back at 50,000 miles!

???? What's going on here ?

..... small cycles are better than big cycles... that's the point. Using 10% of your batteries capacity 5 times will result in less wear and less REAL capacity loss than using 50% once... that's the point.

 

[TimothyHW3]

..... small cycles are better than big cycles... that's the point. Using 10% of your batteries capacity 5 times will result in less wear and less REAL capacity loss than using 50% once... that's the point.

Sure, but having the battery stay at 4.15V all night at 90% will result in even more wear, than cycling 40%-80%, which is the recommended scenario for optimum battery life span and usability.

If you are going to do small charges then charge from 45%-75% and NOT to 90%. This might also be bad for the BMS, but at least you will have the smallest degradation and theoretical 3000 cycles.

"4.15V 400–700 cycles" which on a LR will result in 120,000-200,000 miles


4.05 850–1,500 80–85% 310,000 miles
4.00 1,200–2,000 70–75% 500,000 miles

"In terms of longevity, the optimal charge voltage is 3.92V/cell. Battery experts believe that this threshold eliminates all voltage-related stresses; "
How to Prolong Lithium-based Batteries - Battery University


And having a charge of 70%-90% will also trick your BMS and never give you your "full capacity"

So in summary, charging from 70%-90% and letting the car sit at 90% plugged in through the night is a loose-loose scenario both for the BMS and battery.

For anyone else reading, do your research. I am out.

 

[nwdiver]

Sure, but having the battery stay at 4.15V all night at 90% will result in even more wear, than cycling 40%-80%, which is the recommended scenario for optimum battery life span and usability.

If you are going to do small charges then charge from 45%-75% and NOT to 90%. This might also be bad for the BMS, but at least you will have the smallest degradation and theoretical 3000 cycles.

"4.15V 400–700 cycles" which on a LR will result in 120,000-200,000 miles


4.05 850–1,500 80–85% 310,000 miles
4.00 1,200–2,000 70–75% 500,000 miles

"In terms of longevity, the optimal charge voltage is 3.92V/cell. Battery experts believe that this threshold eliminates all voltage-related stresses; "
How to Prolong Lithium-based Batteries - Battery University


And having a charge of 70%-90% will also trick your BMS and never give you your "full capacity"

So in summary, charging from 70%-90% and letting the car sit at 90% plugged in through the night is a loose-loose scenario both for the BMS and battery.

For anyone else reading, do your research. I am out.

Small cycles; smaller the better + keep SOC <~90%.... doesn't have to be more complicated than that... charge frequently.

 

[TimothyHW3]

Small cycles; smaller the better + keep SOC <~90%.... doesn't have to be more complicated than that... charge frequently.

View attachment 473252

You can't just read one sentence that you liked and quote something out of context - you have to read the whole thing. Go back and read about voltage, high voltage at 90% (4.15V), the available discharge cycles. Figure 6: Capacity loss as a function of charge and discharge bandwidth.*...

Bye

 

[nwdiver]

You can't just read one sentence that you liked and quote something out of context - you have to read the whole thing. Go back and read about voltage, high voltage at 90% (4.15V), the available discharge cycles. Figure 6: Capacity loss as a function of charge and discharge bandwidth.*...

Bye

???? Um.... yeah... to repeat what ~every battery researcher has found... smaller cycles are better for the battery.... AND staying away from high SOC... which has nothing to do with smaller cycles being better...