You're probably right about the temperature factor...
No supercharger anywhere around me...closest is about 400 miles away...don't get me started on that...
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Battery Care & Maintenance
- Thread starter islandbayy
- Start date
No supercharger anywhere around me...closest is about 400 miles away...don't get me started on that...
Each cell is individually heated and cooled, well, not individually, but coolant is flowing to each individual cell. The car cannot just decide, that say, cell #6323 is running a bit warmer then the rest, and decide to heat just that individual cell. As for if each cell is individually monitored on a 1 by 1 basis for voltage or temps, only tesla can answer that, at least until I pop open my battery pack.
As far as my observations have shown, the pack does balance at lower states of charge, however, it is either not as quickly, or not as often. I can only go by my observations, as this is one of those things that only Tesla knows. I do not believe the car would allow a individual cell to get to the point of damage due to imbalance, however, keeping all the cells in balance is very important as well.
I have added some links back in the initial post below the video. If you have not seen them yet, please take a peek. They provide some good information on Lithium batteries and balancing/equalization and charging.
Now, I cannot speak for everyone, but yes, some people appear obsessed with just squeezing as much out of their batteries as possible just to see if their is any degradation. I can only speak for myself, and for me, I do it because I NEED every mile I can get out of my battery pack. On top of that, balanced pack also yields better performance and overall longer total life. I've mentioned before I run my car down to Charge Now regularally, and in many instances, it was that extra mile that I squeezed into the pack, that determined me making it home, or stopping and sitting on a 120v outlet for a hour or more.
As for the p120. I got tired of my 60kW pack so I bought a crashed 60 and doubled up my battery
(just kidding, but I do have some battery fun coming in a few months, once I get some money together to buy a crashed MS85).- - - Updated - - -
Yah, wouldn't worry about it. I seriously doubt any lost range. Just give it a month or so until it starts warming up. You should be fine.
You misunderstood my comment: I drove the car down until there were only 9 rated miles left to be used, then I charged to 100 percent of the 40 pack . I lost a mile 129 to 128. 10% loss since I have had the car 8 months 6000 miles. WHY ISN'T TESLA COMING FORWARD WITH THE INFORMATION on the proper method to charge for max range.
bonnie
I play a nice person on twitter.
He originally got in the 140's. Only Tesla can really answer that. Have you actually BROUGHT it into a service center yet? or just contacted tesla via phone? I'd make a appointment and have a technician check it out. A Tech can plug in his laptop and take a nice detailed look at the vehicle as well.
Also, do you have single or dual chargers? If you have dual (as the 40's cannot supercharge), stop by a service center when the battery is run down a bit, to say, 90 miles, and then use the 80 amp HPWC to charge back up to max. Try and make sure the pack is nice and hot before charging too, by flooring it a few times. You can also try that at home or on a 14-50. I want to see what the affect of a hot battery is, and if you have a range change.
Also, any chance you can download Visual Tesla, VisibleTesla and upload a screenshot of what the charging screen looks like when charging is Complete? I just want to get as much of a idea as possible whats going on and try and help.
glhs272
Unnamed plug faced villian
Tesla does not talk about balancing at all. From what I have found on my car is that it won't do any active balancing (running the charger in pulses) during standard 90% charge. The charger/umc definitely stays off. I would assume your max charge of 72% does the same thing. Not that you want to hear this, but one sure fire way to max range charge like I do is to pay Tesla to un-lock your 60 battery and run it as a 60. That would help your range concerns as well... just a thought. I wish my car was just software locked 85 and I could upgrade freely.
On another note, I am trying a range charge tonight. It has been about a month since the last time. On that prior trip it included 2 range charges and 2 supercharger visits. Last time I would get a 202 rated miles max charge from my umc at home @ 20*F temps and during a supercharger visit on the way back I got 204 rated miles. However I did not let it totally finish charging and it never got to balancing on the supercharger. Tonight I my range charge got up to 204 rated miles then dropped down late during balancing to 203 rated miles (227 ideal miles). Ambient temps are at -2*F. I did have some pre-heat on to keep the pack a little warmer towards the last 45mins of charging. After it finished I drove the miles back off until 178 miles. I then standard charged to 90% and it charged for about 7 mins and ended with 181 miles rated charge. Normally it would standard charge to 179 or 180 if the pack is a little warmer. I did just get done driving it so may the pack is a little warmer than usual. I will try another session of range charging tomorrow and see if any differences result.
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Can't speak for Fred, and I know you mean well, but if Tesla suggested that, I wouldn't have a very good reaction. Kind of like saying, "nice little car you got there, but unless you want to see it continue to degrade prematurely, give us another 11K." Not exactly, because we would get the additional range of a 60, but seeing as we didn't want or need that additional range when we made the decision to purchase that car, it is not really an acceptable solution.
I've seen my max range drop approximately 15% in 9000 miles - not what I had signed up for.
When they made the decision to give the 40'ers crippled 60's, it seemed like a good idea, since for those of us who still had the cars after 5 or 6 or 7 years and the natural battery degradation brought us down to where it is now for some of us, we could pay for the upgrade and be happy campers again. If they had told us we would be seeing that level of degradation after less than a year because we couldn't fully charge the battery, I know that I wouldn't have made the purchase.
Chas F
Model S 60kWh #P6396
Without going thru this entire thread to see if this has been suggested before, it seems to me an answer could be that Tesla develops a balancing process as part of the yearly maintenance. This would cover the 40's as well since Tesla has full control over the level the battery can be charged to.
glhs272
Unnamed plug faced villian
Yes, if Tesla were to make that suggestion that would be very bad and a good way to make an anti-customer. That was why I was suggesting it
and really only if it was something he was considering anyway. Like if he felt that the 40's range wasn't enough for his actual usage and/or he underestimated his daily usage. Meaning he has an "out" for getting more range that us 60 owners don't have. Not trying to stir things up, just trying to be helpful.The range my 60 has at max charge has not changed appreciably, but I don't think that it is anything unique to my 60 or islandbayy's 60. I suspect it is just how they are being used. Keep in mind, just a couple of months ago Islandbayy was reporting that he couldn't get more that 192 miles from a range charge. Now a few months later he is getting up to 208. So to me that says this is not a permanent degradation issue. I think (could be wrong) that mostly is related to temperature and balance of the pack. Islandbayy certainly does not baby his pack. He full cycles it often (large depth or charge) which should put the most wear on his pack. It may be that this type of usage is actually better for keeping it in balance. Or, it maybe just doing a range charge at a supercharger that is making the difference.
I don't expect anyone here reading this to do anything to their cars such as range charge or balance or anything. I say these things for discussion purposes. I will however, put my money where my mouth is and do this experimenting on my own car.
For those who are having real issues with their cars and don't want take amateur advice from us on TMC, they really should go to Tesla for this. And if we are lucky, they will share what they have learned.
Update:
As you can see, Islandbayy's 60 is not unique. I am at 14,500 miles and still get a 203mile range charge at -2*F. I suspect it will do better when it warms up and with a little bit more balancing.
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I have not read this whole thread, so I hope I'm not repeating anything or missing a point.
I don't believe balancing cells improves overall life, meaning I don't think it reduces the rate of long term degradation, but I do believe it improves the available range at the time and would be worth doing if you need the extra range but since we don't know how the S manages this, it's currently impossible to time the charging. I don't recommend regularly deep cycling the battery with the hopes that it balances the cells accept for the times you really need to max the range. If you are pushing the battery daily to the point where you are stressing about it on a 40 kW S, I'd highly recommend unlocking the 60kW ability. The folks on the Leaf forum who were constantly deep cycling to test capacity were ironically the one's who appeared to see the fastest long term degradation. The Leaf is a different beast, it doesn't have TMS and likely allows more of the packs capacity to be accessed, but still, I think it is worth erring on the side of caution even with the S. the effect of ambient temperature on capacity has been tracked carefully on the Leaf forum. most of the losses experienced during winter, recover with the warmer weather. While the S does have temperature management, the battery is subject to ambient temps most of the time. from what I've seen, it appears the TMS doesn't kick in unless at the extremes. some warming appears to happen during preconditioning of the car but I'm pretty sure the battery is still effected by ambient temps. warming up the battery before range charging would likely improve the short term capacity. Unfortunately we have no temperature gauge to monitor. I would suggest that it's very difficult with the S to find an apples to apples basis on which to be absolutely sure how much the fluctution in rated range is due to ambient temps vs cell imbalance vs long term degradation. If your garage is conditioned, and the S sits there long enough to "cold soak" the battery to the ambient temperature and you do all the kind of scientific controls that Tony Williams did for the Leaf, then you might be able to nail it down with certainty but wow, it's a lot of work with such a large battery and so many variables that are hard to control.
To max out the range on the Leaf, I would use the prewarming function to heat up the car for sometimes, a couple of hours, then top off the charge one last time, then drive as far as I could without the climate control on. The Tesla S should warm the battery at least some with preconditioning. I would also drive the Leaf very conservatively and on rare occasion in the winter I'd even take along rechargable chemical heat packs to keep my feet warm and eliminate climate control use. fortunately the Tesla S has a much more efficient heater than the 2011/12 Leafs.
As the battery ages and/or if not conditioned and you want to max out the range predictably (down to the mile or your destination), you need to drive in such a way as to consume a consistent MPkW or WPM and adjust the speed by slowing down when you go up hills, accurately keeping the energy draw consistent, calculate periodically to see if you are within range of your destination and adjusting accordingly ... especially important in the winter!
I got pretty burned out paying so much attention to range with the Leaf and decided the 85 kW battery option for the S was worth it's weight in gold... I almost never think about it. It's very important that people factor in the seasonal cycling of range and long term degradation when considering which pack to include with the order of the S. A larger battery allows for more shallow, mid pack cycling, and I'm quite convinced that that will help long term life of the battery, even if it mutes cell balancing in the short run. at the very least, a larger pack gives you precious peace of mind.
the good news is, cold ambient temps most certainly improve long term life of batteries. those who see a big drop in rated range in the winter which bounces back in the spring are likely going to see longer overall life of the pack. with the Leaf, it appears that long term rate of degradation follows a pattern of altitude and latitude surely correlating to ambient temps, the further south you go, the worse it gets. It's going to take a while with the S to see if a similar pattern plays out. I expect that the TMS in the Tesla S adequately protects the pack from extreme temperatures, so we shouldn't see the accelerated, permanent dropping off of range that so many of the Leaf owners down south are seeing during summer but I think it's safe to say that cooler ambient temps will still be better for the battery long term and still tend to reduce range in the short term during cooler months.
I don't believe balancing cells improves overall life, meaning I don't think it reduces the rate of long term degradation, but I do believe it improves the available range at the time and would be worth doing if you need the extra range but since we don't know how the S manages this, it's currently impossible to time the charging. I don't recommend regularly deep cycling the battery with the hopes that it balances the cells accept for the times you really need to max the range. If you are pushing the battery daily to the point where you are stressing about it on a 40 kW S, I'd highly recommend unlocking the 60kW ability. The folks on the Leaf forum who were constantly deep cycling to test capacity were ironically the one's who appeared to see the fastest long term degradation. The Leaf is a different beast, it doesn't have TMS and likely allows more of the packs capacity to be accessed, but still, I think it is worth erring on the side of caution even with the S. the effect of ambient temperature on capacity has been tracked carefully on the Leaf forum. most of the losses experienced during winter, recover with the warmer weather. While the S does have temperature management, the battery is subject to ambient temps most of the time. from what I've seen, it appears the TMS doesn't kick in unless at the extremes. some warming appears to happen during preconditioning of the car but I'm pretty sure the battery is still effected by ambient temps. warming up the battery before range charging would likely improve the short term capacity. Unfortunately we have no temperature gauge to monitor. I would suggest that it's very difficult with the S to find an apples to apples basis on which to be absolutely sure how much the fluctution in rated range is due to ambient temps vs cell imbalance vs long term degradation. If your garage is conditioned, and the S sits there long enough to "cold soak" the battery to the ambient temperature and you do all the kind of scientific controls that Tony Williams did for the Leaf, then you might be able to nail it down with certainty but wow, it's a lot of work with such a large battery and so many variables that are hard to control.
To max out the range on the Leaf, I would use the prewarming function to heat up the car for sometimes, a couple of hours, then top off the charge one last time, then drive as far as I could without the climate control on. The Tesla S should warm the battery at least some with preconditioning. I would also drive the Leaf very conservatively and on rare occasion in the winter I'd even take along rechargable chemical heat packs to keep my feet warm and eliminate climate control use. fortunately the Tesla S has a much more efficient heater than the 2011/12 Leafs.
As the battery ages and/or if not conditioned and you want to max out the range predictably (down to the mile or your destination), you need to drive in such a way as to consume a consistent MPkW or WPM and adjust the speed by slowing down when you go up hills, accurately keeping the energy draw consistent, calculate periodically to see if you are within range of your destination and adjusting accordingly ... especially important in the winter!
I got pretty burned out paying so much attention to range with the Leaf and decided the 85 kW battery option for the S was worth it's weight in gold... I almost never think about it. It's very important that people factor in the seasonal cycling of range and long term degradation when considering which pack to include with the order of the S. A larger battery allows for more shallow, mid pack cycling, and I'm quite convinced that that will help long term life of the battery, even if it mutes cell balancing in the short run. at the very least, a larger pack gives you precious peace of mind.
the good news is, cold ambient temps most certainly improve long term life of batteries. those who see a big drop in rated range in the winter which bounces back in the spring are likely going to see longer overall life of the pack. with the Leaf, it appears that long term rate of degradation follows a pattern of altitude and latitude surely correlating to ambient temps, the further south you go, the worse it gets. It's going to take a while with the S to see if a similar pattern plays out. I expect that the TMS in the Tesla S adequately protects the pack from extreme temperatures, so we shouldn't see the accelerated, permanent dropping off of range that so many of the Leaf owners down south are seeing during summer but I think it's safe to say that cooler ambient temps will still be better for the battery long term and still tend to reduce range in the short term during cooler months.
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I understood you were trying to be helpful, and it is appreciated.
I and others have taken our concerns to Tesla, but as far as I know, after Fremont looks at our batteries (remotely), we all get the same "battery is normal" response. Only time I ever hear any mention of "balancing" is here, never from anybody at Tesla. I will be escalating my concerns within a few days. If anybody has any suggestions re: an appropriate Tesla contact, I would very much appreciate that info.
The fact that some of you have seen essentially no degradation leaves me hopeful that this really is a balancing issue that can have a happy resolution.
glhs272
Unnamed plug faced villian
Ok as promised I did another range charge tonight. Last night I got 203 max rated at completion of charge (was as high as 204 during end of charge). Tonight's range charge yielded 206 rate miles (although got as high as 207 during end of charge). One difference to take into consideration is that it is a little warmer today, ambient temps were 20*F, last night they were -2*F. Is this improvement due to balancing? Maybe warmer temps helped too. I suspect that if it were a 70*F day I would be getting at least 208 rated miles (got 209 when new).
Aha. Thanks, that's very helpful--and thanks for the link, too!
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Sooo, the expectation wasn't that people go read all the Roadster threads
I know that, which is why that comment of mine was parenthetical and included a wink.
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Stupid question, as I've only range charged a few times and don't remember any messages one way or another. Are you saying the car displayed a message like this...or you contacted Tesla and they said this?
There aren't any messages on the screen, but there have been a few posts where people have been told by senior Tesla engineers that they should let the range charge finish if possible.
Kendall, it was islandbayy that did the advising. By message I meant that I didn't get the app showing "Charge Complete".
In other words...the first time I "range charged" this week I let it get to 99% and stay there for 30 minutes, but the HPWC was still showing charging as was the app, albeit at a pretty low rate, when I had to interrupt charging and take my kids to school. I posted that and islandbayy advised that by interupting when I did that I didn't allow the balancing to finish and he advised that next time I try to allow it to finish completely. Which I did.
Sorry for the confusion, it's a long thread and that story was broken up into several posts.
darthvdr
Member
Old geezer like me is finding this topic of battery maintenance a little difficult to understand. From reading this thread along with others, I took away with this and please correct me if I am wrong:
A) Do not leave your battery at 100% for extended periods (10 minutes or more?)
B) Do not drain your battery down to "0".
C) Maintain battery SOC at 50%
D) Charge frequently and maintain SOC between 50%-70%
E) Range charge to balance battery pack once in a while. Perhaps once a month? (for a 15k mile car)
F) Supercharging can throw the battery pack off balance due to its rate of charge, but it should not harm the battery
G) Charge vehicle at 30A if possible when charging at home
A) Do not leave your battery at 100% for extended periods (10 minutes or more?)
B) Do not drain your battery down to "0".
C) Maintain battery SOC at 50%
D) Charge frequently and maintain SOC between 50%-70%
E) Range charge to balance battery pack once in a while. Perhaps once a month? (for a 15k mile car)
F) Supercharging can throw the battery pack off balance due to its rate of charge, but it should not harm the battery
G) Charge vehicle at 30A if possible when charging at home
glhs272
Unnamed plug faced villian
A) Correct. However you need to have it 100% to balance.
B) Correct, avoid 0 when possible. Run to 0 when you have to.
C) Only for storage. 70-90% is better for daily usage.
D) Correct. Smallest depth of charge is best.
E) Correct, or when you need to squeeze the most miles out of your pack. It may take 2 or 3 range charges to see much difference.
F) Actually a supercharger can balance the pack quite well if allowed to range charge to completion. But operating the car from 0 to 90% will cause the pack to go out of balance eventually, regardless of supercharging.
G) Not sure if this helps any.
darthvdr
Member
50% is just fine if you don't need to drive that many miles. Tesla Ownership told me that in order to maximize long term battery life, keeping the battery charged in the 50%-60% range is best. This is why I keep my battery at 50% and only charge higher in the morning and when I expect to drive the car. For instance, if I have no appointments tomorrow then I keep the battery at 50%. If I have some appointments, or expect to go somewhere, I increase the charge to 70% or 80% depending on what I expect to need. By the time I get home, I am usually in the 30%-50% range and charge back to 50% until I need to drive again. I have an HPWC and can charge quickly, so time is not generally an issue.
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