Charging everyday?

[SSedan]

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.
.

I actually was able to regain 5 miles by discharging below 10% and recharging over 90 with my 2014 P85. Later found out the other 10miles I had lost were due to an update capping cell voltate lower, but I was able to reclaim 5 at one point.

In cold weather especially I charge daily but might only put on 15miles.

 

[Lindamon]

I’ve owned my X (Raven Performance) since August 1. Picked it up with 5 miles on the odometer, it now has 6100+. When I picked it up, the available miles at 90% was 270.

I plug it in every time I return home. Tesla wall charger, 10kw @ 40 amps. Set at 90% charge limit. I have never charged to 100%, haven’t needed to as of yet.

I drive almost everyday. Most days I use between 10% and 15%. The lowest I have been was around 28%. But 80% - 85% of my charges are from 75% to 90%, or less. Sometimes twice in one day, as I said I plug it in every time I return home, even if I plan on going out again that day.

I don’t drive it particularly gently, I don’t speed (much) but I like acceleration to the speed limit. I keep it set on Ludicrous.

As of today, at 90% charge I still show 270 miles available. Haven’t lost one mile. Nothing has changed since I picked it up, except perhaps I actually enjoy driving again.

 

[TimothyHW3]

You guys surely missed that this is a

I actually was able to regain 5 miles by discharging below 10% and recharging over 90 with my 2014 P85. Later found out the other 10miles I had lost were due to an update capping cell voltate lower, but I was able to reclaim 5 at one point.

In cold weather especially I charge daily but might only put on 15miles.

You guys surely missed this is a 3 forum?! The 3 has different cell outlines, different chemistry and BMS.
From reports of other users and what Tesla is suggesting, it seems that the car works in a completely new way.
It is as if you are comparing a BMW with a Honda...

 

[TimothyHW3]

I’ve owned my X (Raven Performance) since August 1. Picked it up with 5 miles on the odometer, it now has 6100+. When I picked it up, the available miles at 90% was 270.

I plug it in every time I return home. Tesla wall charger, 10kw @ 40 amps. Set at 90% charge limit. I have never charged to 100%, haven’t needed to as of yet.

I drive almost everyday. Most days I use between 10% and 15%. The lowest I have been was around 28%. But 80% - 85% of my charges are from 75% to 90%, or less. Sometimes twice in one day, as I said I plug it in every time I return home, even if I plan on going out again that day.

I don’t drive it particularly gently, I don’t speed (much) but I like acceleration to the speed limit. I keep it set on Ludicrous.

As of today, at 90% charge I still show 270 miles available. Haven’t lost one mile. Nothing has changed since I picked it up, except perhaps I actually enjoy driving again.

That is interesting. It is not a 3, but maybe the ravens are somewhat similar(not identical though, as more cells, different BMS etc.!)
Ok, could you please note and report back in 6 months how that goes? You do understand the BMS takes time to get screwed? Also you did go below 30% so that might have helped calibrate it

From what we have seen, as soon as they do a reset, if you continue with the routine it will mess up in about 6-8 weeks. That is barely the two months you owned it. So 6-8 months of you charging from 70-90% would be a nice benchmark. But it would be nice if you can track your charging accurately.

 

[jerseygirl18]

See below

View attachment 471584

this true for Model X also?

 

[Lindamon]

That is interesting. It is not a 3, but maybe the ravens are somewhat similar(not identical though, as more cells, different BMS etc.!)
Ok, could you please note and report back in 6 months how that goes? You do understand the BMS takes time to get screwed? Also you did go below 30% so that might have helped calibrate it

From what we have seen, as soon as they do a reset, if you continue with the routine it will mess up in about 6-8 weeks. That is barely the two months you owned it. So 6-8 months of you charging from 70-90% would be a nice benchmark. But it would be nice if you can track your charging accurately.

I will report back when I first see a change. I’m not going to bother with tracking anything though. My driving habits are fairly consistent. I’m not particularly concerned about any minor loss over that time, as I understand it most batteries lose a small percentage quickly when new, and then level off in a slow degradation, so I am expecting it. I understand the BMS could be off at some point as well, but I don’t really care if it’s a small amount, I don’t ever plan on going below 10%. Actually, 20% feels like a good hard deck for me.

I am planning on a long cross country drive next summer (Florida-Colorado and back), so I’ll have a lot more supercharger use. We plan on doing a lot of tent camping at RV parks to use the 14-50’s there overnight. I feel slow charging is always preferable to fast charging. I’ve only used a supercharger twice since I bought mine, and then only charged to 80% (high use in my area). I’ll have some short supercharger trips coming up soon before the long one, just to get a feel for things. Perhaps using a supercharger more will show a difference. After the Colorado trip, a year of ownership, and perhaps a total of 25-30K or more miles will have passed. Very interested to see how the battery looks then.

I kept my last F-150 for 17 years and 220,000 miles, and plan on keeping my X a long period as well, unless something really cool comes from Tesla in that time that can’t be installed in my car, and I feel I must have (likely, if the truck has a good size battery for towing, and looks really cool). I am interested to see how the battery holds up over many years and miles.

I’ve been doing a little research on current Li-ion battery technology, and though a layman whose opinion really matters not, I believe we are still in the infant stages of battery science. Things will only improve from here, and I’m happy to be an early adopter.

Cheers!

 

[Lindamon]

this true for Model X also?

Yes,

 

[TimothyHW3]

I will report back when I first see a change. I’m not going to bother with tracking anything though. My driving habits are fairly consistent. I’m not particularly concerned about any minor loss over that time, as I understand it most batteries lose a small percentage quickly when new, and then level off in a slow degradation, so I am expecting it. I understand the BMS could be off at some point as well, but I don’t really care if it’s a small amount, I don’t ever plan on going below 10%. Actually, 20% feels like a good hard deck for me.

Well, unless we have somewhat consistent data, we can't make any conclusions. You might not care for degradation, but a lot of people do and it would be great if we can have as much info as possible.

And if you make statements that "nothing changed in the last 2 months", for us to see what might be the better practice, somewhat hard data will be a bonus.

I am planning on a long cross country drive next summer (Florida-Colorado and back), so I’ll have a lot more supercharger use. We plan on doing a lot of tent camping at RV parks to use the 14-50’s there overnight. I feel slow charging is always preferable to fast charging. I’ve only used a supercharger twice since I bought mine, and then only charged to 80% (high use in my area). I’ll have some short supercharger trips coming up soon before the long one, just to get a feel for things. Perhaps using a supercharger more will show a difference. After the Colorado trip, a year of ownership, and perhaps a total of 25-30K or more miles will have passed. Very interested to see how the battery looks then.

That will be interesting indeed, make sure to post here. Charging on superchargers might help reset the BMS as you will be driving 20%-80% or thereabouts pretty often. So it would be interesting to have the data before the trip. Somewhere before the summer would be a good indication. If you can keep charging at 70%-90% daily that will be a bonus.

Also make sure to change to km instead of miles to measure degradation at 100% more accurately.

 

[mswlogo]

You are missreading something about this chart. 90% is high SOC and is not good for the battery.

Also, small cycles are good for the battery itself, but is not good for the BMS, that actually calculates that capacity. So if the BMS is misscalibrated while never allowing it to go lower than 65%, all of these charts will not help you, since your BMS will think you only have 80% of the kWh available, even though there are more.

It is like having a full tank in reality, but the gas gauge thinking you only have 80%. Until you "reset" it, or change it in a gas car, you will never get the full range, even though it is there.

If you follow that graph and for a good BMS, I think charging between 30%-80% is the best middle ground.

I agree with most of your comments. But a miscalibrated BMS is completely harmless. It won’t prevent a full charge or from being able to use the true range of the battery. The only problem is it might mislead you into thinking you have more or less than what’s really there. And it can be recalibrated. In the long term it’s harmless. If 75-65 is indeed most healthy and works perfectly for someone’s use case, who cares what the display says daily or on the next full charge.

One thing that people don’t account for though is warming. In extreme cold conditions warming your battery just to charge 10% is expensive and probably not the best for the battery either. once the battery is at ideal temp for charging I think your better off putting more into it at a time.

There are temps where it just slows the charging and won’t cost more, just time. And it will warm the battery naturally through charging. But there are temps where it will spend energy to condition the battery for safer/faster charging. What those exact temps are I’m not sure. It does depend on SOC and charge rates.

Also as has been mentioned about the charts in a dozen threads is somewhat misleading. Keep in mind that 1000 (full) charge cycles is approx 300,000 miles. So only the first 10% of the charge is at all relevant. If you take the best case and worst case at 1000 cycles (300,000 miles) you are talking the difference of 97% vs 91% capacity. And if you look at say 333 cycles (or 100,000 miles) it’s like the difference between 98% and 96%.

And I don’t think that chart applies to Model 3’s exact chemistry. There are other factors that might be larger like what temp the battery is kept at on average, charged at on average and the average SOC.

 

[TimothyHW3]

I agree with most of your comments. But a miscalibrated BMS is completely harmless. It won’t prevent a full charge from being able to use the true range of the battery.

No, this is factually wrong. If the BMS thinks you only have 67kWh you will be able to drive those 67kWh and not more. Even if there are 75kWh "physically and possibliy" available. Because the car has shutdown mechanisms that prevent it from going further if it thinks it will harm the battery.

There is no way for the car to actually "know" that you have more capacity, if the BMS tells it otherwise.

This is easily provable - anyone with a 10% or so "BMS degradation" that shows about 280 miles range @ 100% should do a rated consumption run of about 280 miles and see how far they can get.

If you are right - 300 or so miles, if I am right less than 265-70 miles...

And do the same run after the BMS is reset to show 310 miles @ 100% from Tesla and see if they get more range.

 

[mswlogo]

No, this is factually wrong. If the BMS thinks you only have 67kWh you will be able to drive those 67kWh and not more. Even if there are 75kWh "physically and possibliy" available. Because the car has shutdown mechanisms that prevent it from going further if it thinks it will harm the battery.

There is no way for the car to actually "know" that you have more capacity, if the BMS tells it otherwise.

This is easily provable - anyone with a 10% or so "BMS degradation" that shows about 280 miles range should do a rated consumption run of about 280 miles and see how far they can get.

And do the same run after the BMS is reset from Tesla and see if they get more range.

I have certainly not tested this. But the BMS Calibration as far as I understand is a prediction curve.

When it goes to charge it doesn't care what the prediction is, it will finish when it thinks the batteries actual measurements are with in spec. for being full (independent of BMS calibration). Likewise, if it says you have 200 miles and you drive 200 miles (and for argument sake you drive exactly at the EPA rating) but as it goes along it will see you have more capacity left it will allow you to go further than what it predicted based on actually battery levels.

Basically as you approach the two extremes the BMS Curve will always be more correct (from a percentage point of view). The BMS prediction curve is an estimate of when you are in-between (or the other end), which can be off by a lot with some charging patterns.

If you have evidence of that not happening and like you said the car would shutdown after 200 miles (in my example) even when there is plenty of real capacity left, I'd be happy read up on those references. With the available CanBus monitoring tools out there I'm sure this situation has been covered. Sorry if I'm wrong. I'd be shocked if you are correct though, it would make little sense to behave that way. But it's possible it's well beyond my understanding of why it would behave that way.

For argument sake you can think of my 200 miles as like your fixed 67kWh amount.

EDIT: Read the last post in this thread by @shred86 (for some reason you can't link individual posts any more). He say's exactly what I just said and he there has been testing to show it.

BMS/Balancing cells

 

[TimothyHW3]

I don't have any degradation nor BMS issues to test. There are plenty of people that read and complain about range here - I guess it wouldn't be too much to ask them to test it, if they wanna know if its BMS or real degradation or both... From what I have seen here, these tests of 100% range on a 280 miles just end up exactly as predicted - at around the 270-280 miles mark.

Nor you nor me know how the BMS works exactly, so it is hard to speculate unless it is tested.

 

[mswlogo]

I don't have any degradation nor BMS issues to test. There are plenty of people that read and complain about range here - I guess it wouldn't be too much to ask them to test it, if they wanna know if its BMS or real degradation or both... From what I have seen here, these tests of 100% range on a 280 miles just end up exactly as predicted - at around the 270-280 miles mark.

Nor you nor me know how the BMS works exactly, so it is hard to speculate unless it is tested.

From what I have seen everyone is basing their "BMS Calibration loss" on a prediction and nothing else and not actually running their battery down. It's also not easy to use exactly a fixed amount of kWh to really test how far off it was. And what it reports for what you used might be off as well (probably not though).

 

[TimothyHW3]

Your link to the other thread's post is a hot mess.
He first starts talking about cell imbalance, then transitions to the BMS and his TLDR exclusively talks about cells and imbalance and battery health and never mentioned the BMS again... He also confirms, based on other users, the things I suggested - charge to 100% to balance the BMS. But this is S and X stuff. The Model 3 doesn't quite work like that or it seems like it.

Not sure why you would quote that post as a confirmation of a contradiction to anything I said.

There are at least 2 Bjørn Nyland videos where the car shutdown because of bad BMS. It is a different kind of error, but it proves the point that a misscalibration in the BMS, regardless of how the battery health is, will result in less real range.

 

[Rocky_H]

Sure.... 80 - 68 - 80 would be better than 90 - 78 - 90 but only marginally.

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...

???? What's going on here ?

Yeah, I don't get it either. It's like he's not reading what you said at all. You just said that using this in a lower state of charge band is better than in the higher state of charge, and then he's telling you you're wrong and flaming you, talking about how 90% is too high and lower is better.
That is literally what you just said.

 

[TimothyHW3]

That is certainly not what he said.

He said and I quote" that charging from 70-90% daily is fine". He also said that daily is good for the battery, rather than my suggestion of 30-40(whatever your schedule is) to 80-90% is better.

I said that charging from 30%-80% is better for the BMS, but also, to an extent, for the battery...

I also said that you should plug in at 30% as soon as you get there and never let the car idle at 90% all night, but rather schedule the charge so that it ends up at 90% right before you leave...

What I also said is that keeping the car high in the 90% each night(because you reach 90% from 70% in about an hour after you plug in and the car stays at 90% for 10-12 hours straight...) is bad for the battery as evident from the 4.15V.

And I also said that there is a difference between a healthy battery and healthy BMS. You need both.

You should read exactly what is being said and not just randomly press the dislike button...

 

[Lindamon]

Well, unless we have somewhat consistent data, we can't make any conclusions. You might not care for degradation, but a lot of people do and it would be great if we can have as much info as possible.

And if you make statements that "nothing changed in the last 2 months", for us to see what might be the better practice, somewhat hard data will be a bonus.



That will be interesting indeed, make sure to post here. Charging on superchargers might help reset the BMS as you will be driving 20%-80% or thereabouts pretty often. So it would be interesting to have the data before the trip. Somewhere before the summer would be a good indication. If you can keep charging at 70%-90% daily that will be a bonus.

Also make sure to change to km instead of miles to measure degradation at 100% more accurately.

One correction, I never meant to imply I didn't care about degradation, I do, but I accept the fact that my batteries will degrade some over time. From what I have read, there is always a little degradation (up to 5% or so? not really sure) right off the bat, and then it levels off. I accept that, it's part of my understanding of a downside of battery electric vehicles.

Even if I were to keep closer track of my charging and driving practices, anything I were to post here is still nothing more than anecdotal, so there is no science behind anything I say, just my personal experience. As far as my practices regarding my statement that "nothing changed", and what practices might be best, well, all I can say is I plug in in all the time just like Tesla says to do, and the majority of my charges are between 70% and 90%.

I spent almost twice as much money on my X as any car I've ever bought, so I want to take care of it for sure. I personally believe that following the manufacturer's recommendations is always the smartest thing to do. I fly airplanes, and I also follow Lycoming's recommendations on how to care for my engines, it just seems like the best way to go.

I can switch to kilometers, but I have no baseline as I never looked at it in km when I picked it up. I'll check that today though, once it charges up all the way.

I'm not sure how I can measure any actual degradation accurately in my car anyway, as you point out, the BMS can become inaccurate, so there is no way for me to know whether the BMS is off, or the battery has degraded, or a little of both. The graphs I have seen show that after 150,000 miles, an average of 9-10% degradation, most of it early on I believe, so if I stay in that ballpark, I'll be relatively happy.

 

[BE_M3]

Wow, so many different theories here, not sure what to think.
I always charge to 90% when needed, at around 150 to 200 miles.

 

[Rocky_H]

That is certainly not what he said.

It was copied and pasted.

You should read exactly what is being said and not just randomly press the dislike button...

You are out of your mind.

 

[RainyDaze]

Question - Somewhat on topic. Since I’m still waiting for my SR+ (in week 6 now) I can’t figure out the following. I know you can set a departure time for your charging to finish so as not to hold a high soc for long. Can this setting be made “semi permanent “ so I can plug in ever night and not worry about having to reset it?

As a side note thinking about running an SR+ within 50% (30%-80%) of its max range while possible most days for me does add some anxiety.