paranoidroid
Member
Since it looks like you drive 50 miles/day or less on average it would be much better for your battery to charge to 60 or 70% instead of 90% and just do 90% the night before you know you need the range.
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Model 3 Performance Battery Degradation One Month (Story)
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Since it looks like you drive 50 miles/day or less on average it would be much better for your battery to charge to 60 or 70% instead of 90% and just do 90% the night before you know you need the range.
Yea only included part of the history, the past few weeks have been work from home and holidays so just local driving that's why I had that one set to 75%. I just did the 90% again last night to see if it made a diff with this version. Now I will go back to 75% but then next week back to driving to the site (at least 150-175 miles) so those days will be at least 90% since it's cold and Wh/Mile is well over 300 and will do at least 1 100% just for a test to see where that lands. Also will be interesting to see if it actually charges to 100% or does what it has always done in the past 99% or 98%.
But I guess the main point is 2018.44.2 3b2a5c3 changed the displayed rated range for given battery. As I gained several miles overnight with the same battery just new firmware.
No it wouldn’t be “much better”. Maybe there’s a statistically significant difference in capacity after many years, but no meaningful difference. Really I dont understand why some Model 3 owners are so obsessed about the battery. We have lots of experience from the Model S that charging to 90% routinely is just fine.
As one data point, my Model S was chsrged to 90% every night for five years, and 100% for trips several times/ month, and lost 5% range after 5 years. You’re not going to do better than that by limiting your charge to 60 or 70%, but you’re going to make the range estimate inaccurate. Even if it would lower the range by a few miles after many years, if that’s going to have an impact on your use then you bought the wrong car.
As you know well the internet is littered with conflicting post about this topic from charts by experts to Elon's tweets for 80%. I'm not really obsessed I would say interested in maximizing the cars most expensive replacement part (the battery). Let's be honest I bet 99% of the Model 3 batteries never get replaced under warranty since they would have to drop to 70% and except for a really major failure inside that's really unlikely to ever happen. So take the original 310 * .70 = 217 and for me that's low for some of my weeks work commutes, and low for cold weather for sure at least for me. I did buy the right car and plan to keep it until it dies of old age. So if some simple thing like maybe charge to 75% and more when needed gives me several % more life after 100k then 200k it's easy to do and take. For sure all the battery experts seem to agree on one thing that these batteries would last forever if maintained around 50% charge all the time. Granted this is not practical for a car so no one is saying to do this. But with the abundant amount of supercharges, at least for me I have the wall charger @ 48 amp, so if I charge to say 75% and all of a sudden need more it's easy to get fast.
I should note for all that I have seem proof that charging to just 75% can also have its own issues and cause your numbers to be off. So really we are all just sharing here because the Model 3 battery is not exactly like the past models. That said it's clear that it won't be for several years until we really know how and what charge lever if any effects the model 3 batteries. So for now we are all just expressing our opinions and there is no real long term data for any of us to base anything more.
Yes model S battery is not much different but still it's in not the same, also the model 3 has a much different cooling and charging system so overall things are not the same so results may not be the same.
I am sure that charging to 90% everyday is not going to have a significant impact over the long term. At this point I'm playing with the new toy it's possible that soon I will get bored and just charge to 90% everyday and forget about it. Generally this is just a simple discussion.
Disagree. The internet is littered with... litter. You can find crap to support ANY point of view, but that doesn’t mean any point of view is correct.
There are also facts out there. @TexasEV is correct. Numbers don’t lie. There have been numerous long term data points. Tesla batteries lose 5% quickly, and almost nothing after that. Regardless of how you charge it. So 90 vs 70: immaterial!! That is in distinct difference to other automotive HV batteries, which lose more. Tesla’s battery management system is genius at protecting us from ourselves.
Tesla battery degradation at less than 10% after over 160,000 miles, according to latest data
Not sure why this forum topic is so testie, Yikes!
First of all you replied: "Disagree. The internet is littered with... litter. You can find crap to support ANY point of view, but that doesn’t mean any point of view is correct."
I guess you misread what I said as I agree with you 100% so no idea why you disagree with me when I said exactly that.
Second I was actually going to post that same linked data but just could not find it since again it seems reasonable. BUT BUT the one thing you Will Not find in any of these charts for each given data point is what that person regularly charged to. So there is no way to know from that data the difference between the loss of a person that charged everyday to 90% and a person that charged everyday to 70%. No one at least not I is disputing the data that is there only the fast that yes loss over given miles is tracked just not daily charge per data point.
Since you got so testie this is the part I will love the most. If you actually read the whole article that you so boldly quoted, the second paragraph under the graphs says this:
"With this said, Jeff Dahn, a renowned battery researcher and the leader of Tesla’s research partnership through his battery-research group at Dalhousie University, said that he recommends charging to only 70% daily in order to extend battery life."
Remember guys the above statement is right out of the article quoted by "tomas" and that from a Tesla researcher on Tesla batteries, so since "tomas" posted the link to the article he must be advocating a daily charge to 70%.
Again all I did was actually read the article (all of it not just the part that supports my POV) in its entity and not do what so many do, quote only the part that supports my argument.
Based on the info you provided I should actually be charging to 70% really we all should, again not me saying this it's in the article you referenced.
So I so much look fwd to your reply since all I did was quote and use your provided info and data that clearly contradicts what you have posted. No rush this is just a friendly forum, relax, take your time, read the article in the link you posted, then reply.
And please guys relax no need to get all worked up.
Except they're not the same batteries.
I know you know that, so I think that you'd recognize that there is some additional unknown here. If I had a car with the same batteries as the S/X, I'd definitely take an immense amount of comfort from the history of how those batteries have held up in the S/X after all these years. As it stands, though, I take some comfort and direction from that six-year history since at base they're still both Li-ion technology, but it's also true that these are new batteries with not the same chemical make-up and so that's the unknown.
Obviously, Tesla/Panasonic have done their best to improve on the older batteries with the 2170 (purportedly higher energy density, etc), and of course the idea is to make better batteries that improve on the older ones, but sometimes the best intentions don't always lead to to better results - history is littered (there's that word again!) or at least liberally sprinkled throughout with improvements that actually didn't improve as originally intended. How will we know if they got it right/better, not worse/wrong, long term with these new cells? Time. Time will tell.
So I don't see what's wrong with trying to maximize battery life in a car that we all own (lease not available - if so, I'd care far less about all of this if I planned on returning it in three years), and may well keep for 5-10 years (that's my plan). What one does now with a battery indeed can affect its condition in that longer term window, and since we don't know for sure if the improvements in the new battery won't backfire or not work out long term as well as Tesla/Panasonic hope they will, it seems prudent to take reasonable actions now to try to make the battery capacity / cycles last as long as you can.
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These are not the same batteries as the S/X.
You know that, so don't you think that there is some element of unknown here, with the new batteries? We all hope that the new batteries are better than the old ones (or at least no worse), but the best way to determine that is to see how they perform, in the real world, for years. The data you link to is a great example of that - for S/X batteries, six years / 160k miles on. Let's hope it's the same or better with the 2170's. In six years, we'll know for sure.
diamond.g
Active Member
Like Tesla's Kim (or is it Kim from Like Tesla) was showing major degradation in the battery meter next to the speedo (100% full as like 242 miles). Somehow they were able to get Tesla to full reset (of I assume the BMS) and all the range came back. They posted on twitter about it. Something like the BMS thought the battery was only 60 something kWh.
That's an interesting data point.
What I also take from that is that it's not just the batteries that are new/different from the S/X ones. The BMS is new, too (again, as with the new batteries, no doubt designed/intended to be an improvement, too). But, still new = untested in the real world, for years, as has the tried and true system in the S/X's.
All signs point to Tesla being better at making/improving their batteries and BMS than, for instance, Nissan (who put out a 30Kwh battery in an attempt to fix the awful performance of their initial 24kwh battery/system, only to see in the real world that it was *worse* performing than the original set-up). Let's hope that continues with the Mod 3 too.
So this is interesting I did a little digging and really this info from Kim is all that is out there and it's not much. Also goes totally against that Tesla battery expert who said 70%. I actually found some similar notes that shallow charging makes the BMS get out of wack. Issue is there just is not enough documented data points yet.
LikeTesla @LikeTeslaKim 21h21 hours ago
Hi @elonmusk, could you please shed light on the best nightly battery SOC for longevity? You previously suggested <80% but service is telling us setting to 90% is the new recommendation as anything less throws off voltage/calculations. #Tesla #ModelS #ModelX #Model3"
LikeTesla @LikeTeslaKim 20h20 hours ago
Replying to @LikeTeslaKim @yanquetino
They then received approval from Fremont to hard reset everything and battery miraculously got all its range back. They said car was reading incorrect voltage and only thought it had 67 kWh available to use due to our 70% charging.
LikeTesla @LikeTeslaKim 16h16 hours ago
Replying to @Everman @elonmusk
They argued until the cows came home that they routinely see people with this issue when charging to 70%. I mentioned Elon’s tweet and Jeff Dahns recommendation but they contacted an battery engineer in HQ and apparently confirmed that it is our charging habits. Saying 90 is best
LikeTesla @LikeTeslaKim 16h16 hours ago
Replying to @LikeTeslaKim @Everman
They were given permission to hard reset our car and it instantly adjusted everything back to a brand new 3. I don’t I’m comfortable keeping it at 90% still!
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LikeTesla is conflating two different issues. One is battery capacity, the other is how the BMS estimates battery state of charge, as it can't be measured directly. The recommendations were related to battery longevity, not how accurately range could be estimated. The issue is if the car is only charged to 70% then the BMS can't estimate state of charge accurately. This was true in the Model S as well-- but perhaps more so in the Model 3.
Not worked up. It is cool if a few people want to graph everything, obsess about it, and discuss the fine details. It is disturbing if a bunch of other Model 3 owners wander into the thread and start worrying unnecessarily and it ruins their experience.
What I think you are seeing from veteran Tesla owners like @TexasEV and me is a bit of deja vu reaction. We've watched each wave of owners go through this same range panic and obsession. We also watched Tesla get a handle on how to best measure the batteries in the early days of the S. I assure you , it was JUST like this. Lots of people experiencing rated range figures that were spooking them. Over several software releases, Tesla improved the estimation, and it stabilized. After a couple of years, people stopped worrying about it. I expect the same with the 3.
WRT the Jeff Dahn comment... old hat, I had read that many times, and I knew it was in that article. Of course... it is well known science that keeping the average SOC as close as possible to 50% is optimal for the battery. So, depending on driving patterns, for someone absolutely obsessed with babying their battery might be better off charging to 70. That doesn't contradict anything I said. What we know from the graph and the many experiences of S and X owners is that the difference is IMMATERIAL in the scheme of things, which was my point. You will degrade 5% over the first year or so regardless of what you do. You will then maybe degrade a couple more % over then ensuing 5+ years. And there's no correlated data that charging to 70 or 90 would be a key determinant.
Charging to 100, however, would be a problem. And part of what threads like this stimulate is a bunch of people unnecessarily doing calibration charges and ironically in the process doing about the ONLY thing that can do their battery long term harm.
So to me the real question is if say someone charges to say 75% everyday thinking it is the best course of action. Even really the car will gladly accept this setting as a daily limit so it's within the general car settings. So just like the Kim at like Tesla did they are eventually in need of a BMS reset? I wonder if the system can self correct say Kim did a several down to 20% up to 90% charges would this have self corrected without a reset? I would hope so...
Further if the car lets you set to 70% but eventually gets well screwed up that is a problem in itself. I myself work in tech and we have similar issues and we do auto corrections after a bit so one would think Tesla does the same.
Bottom line the 3 has a more suffocated (we assume better) battery and charging sys then the S so hopefully the results after x years is actually better.
In the end the real moral is Drive and Enjoy!
Yes I agree. It's the BMS going out of whack; not the battery itself.
So, charge to 70% if you are super-duper-concerned about super-duper-maximum battery life, then charge to 90/100% a bit when the BMS goes out of whack (or have Tesla reset as they did for LikeTesla), and go on with your life . . . (well, keep the 100% SOC bit to a minimum - for me 90% SOC brought back 30 miles of extrapolated 100% range, after doing that for about 10 days)
Essentially, it's the rebalancing act thing that S/X owners have been familiar with for years . . . ("or so I have read" - Spinal Tap, Big Bottom)
@007Bond, given the uncertainly you're describing about the Model 3 batteries, I don't understand your earlier definitive statement that "it would be much better for your battery to charge to 60 or 70%." Stating that as a fact, contrary to the practical experience with Model S batteries over the past five years, is really misleading for new owners and prospective owners and may cause unnecessary concern. Perhaps you meant to say that charging to 60 or 70% might be better for the battery, if the Model 3 battery turns out to be not as robust as the Model S batteries.
All good my friend. If you are a veteran S owner sure I get it. With the 3 it seems to have a better system then the S so hoping end results are also better. I am thinking with the 3 Tesla improved the BMS so that ppl can just charge to 90% and forget about it after all that would make the car a real daily driver. But like a few have said it will take several years until we know as the data is just not here yet for the 3.
As for the 100% I would only do it on a day that I know is going to be be 200 miles or more. So this is not that often and only on days that I know I am going to use almost all of it. It does seem to have some type of calibration affect but I am for sure not doing it just to do it.
I think from what we know the Model 3 battery is actually better then the Model S. At least this is what one would hope since the tech has advanced. We further hope that the BMS is also better so overall battery performance should be better.
But as with anything diff or new we need data over x years to really know if it is better or not. But think of this as I know it the Model S and X do not come with an actually battery warranty where the Model 3 does. At least I think I am correct that the Model 3 guarantees 70% by the end of the warranty where the S and X did not do this at all. So I think we can bet that the Model 3 battery and BMS is better or Tesla would not bank on the warranty. At this point I think I am going to just set the charge limit to 90% and forget about it. Just use 100% for long trips and enjoy.
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