For those owners unhappy with drop in maximum charged range

[NoMoGas]

Peter, yes, I have worked with service/engineering, as have others. The response I and others have received after Fremont looked at whatever it is they look at, is that my battery is operating normally. As I stated, I was told that a new firmware release would restore some of the lost mileage. I did not get that from random forum members. I got that from my service mgr, responding to my multiple inquiries.

There are two other threads related to decreasing range and battery maintenance that I follow. Not trying to be obnoxious, but I would very much appreciate it if general suggestions, which I very much appreciate, were posted there, and this thread saved for its intended purpose.

But here is my question: Did you actually LOSE mileage or does your display just say you did based on driving habits or whatever else it uses to calculate such things? We all know in ICE vehicles the rated range can swing wildly. Up for a test?

Get a friend to tow a uhaul auto transport and follow you. Fully charge the vehicle and drive at a cruise control speed of 55 until the car hits zero. What was the difference between rated and actual?

It's one thing to go crazy because the car lost actual miles, but quite another if the cars calculations are simply ultra conservative. Only one way to know. (The other would be find a station with wheel rollers so you don't actually have to go anywhere or even a track.

 

[markb]

. Up for a test?
.

No.

 

[glhs272]

I wish I knew if this degradation by charging 60-70% all the time is actually permanently bad for the battery, or is it just a temporary thing that will come back later if I need it to... That is, doing range charges is supposedly bad for the battery pack. If this 60-70% babying is only bad for the number I'm looking at when I look at the rated range, I'm not sure I want to do actual damage by doing multiple range charges just to make it look better.

Do you think I could get the range back by doing 90% charges, or do I really need to do the range charge to balance the pack or whatever it is?

If the battery is simply out of balance, then the range loss is real but temporary. I firmly believe that doing a range charge does not "damage" the battery in the sense that if you do one or two range charges you will be loosing measurable range. I have done at least 16 range charges on my car at 16,000 miles. Range charging every day and leaving it there would lead to accelerated wear and possible eventual battery failure. But, that is not what I am recommending. Having a very hot battery and 100% charge is not good for it either. If you bring it up to 100% charge and then drive off the high state of charge shortly thereafter it will likely have very little impact on the long term life of the battery. A long time spent at a high state of charge is when the chemistry in the battery is building up deposits that eventually cover the electrodes to kill the cells. Tesla knows this. They use electrolytes additives that help mitigate this. They have battery cooling to keep the cells from getting too hot. And they likely have conservative limits on the maximum state of charge to prevent the insidious rapid failure of cells. Also, it is probably best to charge to max charge as quickly as possible in order to spend the least amount of time at levels above 90%. So you might even try doing this at a supercharger. Or at least set your charge rate to max amps.

With my car anyway, I have not had much luck balancing at 90%. You could give it a try and see if helps before going for full range charges. So it seems that unfortunately the most effective way to balance the battery is to do the a full range charge. That is just the double edge sword that is. Perhaps later model packs are better than earlier model packs. I am trying to keep this thread alive and get as much input from as many people as possible to get as best a picture from real world users as we can get.

I have not seen any posts here yet that state doing a few range charges have lead to significant range loss. It seems most people either don't see any benefit or they do get some range back. But keep in mind that the first range charge is not going to show "improvement". It is the difference in range between the last range charge and the next one. Assuming you did the two or three range charges at the next charging cycle. Doing a range charge and waiting 2 months to do the next one doesn't count.

If the minor loss of range due to an out of balance pack is insignificant to you, should you bother balancing the pack? Does an out of balance pack harm the pack or the cells in any way? I just don't know. It is likely that even 10 to 15 miles loss of range is not a significantly out of balance pack. How much range loss due to out of balance can the pack tolerate without any damage? Don't know that either. All very good questions. I have not heard anything official from Tesla about any of this, so it seems to be up to us owners to divine this information for ourselves through the trials and tribulations of daily use. For me however, I need the maximum range from my 60's pack. Northern Wisconsin is a charging desert. Until they install a supercharger in Wausau, I need to keep my pack tightly in balance. So all this to say it's your car so it's up to you.

 

[mlaureti]

Thanks for the picture, I will check my battery type tomorrow morning.

Charging habits: I charge @ 70% during winter time and 60% during summer time
Never super charged
Range charged about 8 times last summer, did about 6 this winter.

When I speak to service I always talk in terms of Ideal range because they have been saying that ideal range adjusts based on your driving habits
In ideal range I used to get 300 miles and now I am getting 285 of max charge

Like probably most owner, I babysit the battery based on Tesla's recommendations.

I registered a formal complaint because I am not satisfied with the "There is nothing abnormal with your battery pack" answer.

Apparently this is being brought up to the chef engineer responsible for our area. To be continued.

 

[kjl]

Well ****, I saw this thread and got paranoid. I've also been babying my car (it's a 60kWh), and have been charging to 60-70% every day (about a 120 mile charge) for the last few months. I noticed that this charge level has dropped (125 down to 115 or something like that), so I did a full non-range charge to test it, and my rated range on a full charge has dropped from about 178-179 miles, where it was pretty stable for months, down to 162 miles today. That represents about a 10% capacity drop.

I've had it 7 months, 7600 miles on it. What the hell.

Just another data point for you all:

So, about 3 weeks ago (when I posted this previous message), I had been babying my battery and charging to 60-70% everyday, and noticed that my 90% charge had dropped to 162 miles(!). I did one range charge in an attempt to get it to rebalance the pack (btw, I exchanged emails with a service advisor and he said "The battery does not do any kind of rebalancing"), and it didn't do anything. But since then I've been charging up to 90% every day instead of 60-70% and my 90% charge has slowly but steadily been creeping back up. On 2/14, when I posted last, my 90% charge was 162. A few days later, the 90% charge was 163, then 164, etc.. This morning my 90% charge hit 167 miles for the first time, so I've "recovered" 5 of these lost miles in range since I stopped charging to 60-70%.

My driving habits have not changed at all over the last ~6 months, and the morning temperatures of my garage have not changed either over the last month or so (outside temperature as reported by the car is 55-60 degrees every morning - some days warmer and some days colder, but not correlated with higher or lower ranges).

I'm remaining hopeful that my range continues to creep back up from 167 back up to the low-mid 170's, but we'll see. I wish I had more information. I still have no idea if my charging to 60-70% was actually the cause of the temporary drop in range or if it was just correlated, not the cause, and if it was the cause, if the drop is just temporary or if charging to 60-70% all the time will be worse in the long run than charging to 90% every day.

 

[Jeff Miller]

Just another data point for you all:

So, about 3 weeks ago (when I posted this previous message), I had been babying my battery and charging to 60-70% everyday, and noticed that my 90% charge had dropped to 162 miles(!). I did one range charge in an attempt to get it to rebalance the pack (btw, I exchanged emails with a service advisor and he said "The battery does not do any kind of rebalancing"), and it didn't do anything. But since then I've been charging up to 90% every day instead of 60-70% and my 90% charge has slowly but steadily been creeping back up. On 2/14, when I posted last, my 90% charge was 162. A few days later, the 90% charge was 163, then 164, etc.. This morning my 90% charge hit 167 miles for the first time, so I've "recovered" 5 of these lost miles in range since I stopped charging to 60-70%.

My driving habits have not changed at all over the last ~6 months, and the morning temperatures of my garage have not changed either over the last month or so (outside temperature as reported by the car is 55-60 degrees every morning - some days warmer and some days colder, but not correlated with higher or lower ranges).

I'm remaining hopeful that my range continues to creep back up from 167 back up to the low-mid 170's, but we'll see. I wish I had more information. I still have no idea if my charging to 60-70% was actually the cause of the temporary drop in range or if it was just correlated, not the cause, and if it was the cause, if the drop is just temporary or if charging to 60-70% all the time will be worse in the long run than charging to 90% every day.

There is some reason to believe that the displayed drop in rated range (at a fixed SOC) when you routinely charge the battery to only 60 or 70% is a) not reflective of a real drop in range or battery capacity b) not related to charge imbalances, and c) just an artifact of limitations in the algorithm that Tesla uses to estimate the battery's energy capacity. (For what little it's worth, I mostly charge to 60%.) See post 1017 and following on the "Decreasing range thread" for details:

Decreasing rated range. - Page 102

 

[Chris Naps]

In order to do a FULL balance - one must first charge to 100% - The original poster will not regain miles because he cannot fully charge because he has a 60 KW battery programmed for only 40 KW. The only people who can allow for him to regain battery life is Tesla.

In regards to many of the same replies to this thread - Low rated range is not bad - the battery is simply.. OUT OF BALANCE. In order to regain these miles one must charge to 100%. IT IS NOT GAURANTEED TO REGAIN 'ACTUAL' RATED RANGE THE FIRST TIME ONE CHARGES TO 100%. IT SOMETIMES TAKE 3 DAYS AT 100% TO REGAIN RATED RANGE OR CHARING TO 100% THEN DRIVING DOWN TO 0 THEN DOING IT A FEW MORE TIMES UNTIL YOU WILL BALANCE A PACK.

Charging to 100% does not hurt your battery - it only hurts it when it stays there for a long amount of time.

 

[ecarfan]

Charging to 100% does not hurt your battery - it only hurts it when it stays there for a long amount of time.

Like when one charges to 100% and let's the battery stay at the SOC for three days and then repeats that pattern multiple times as you recommend?

And you recommend this based on what factual evidence?

 

[hans]

In order to do a FULL balance - one must first charge to 100% - The original poster will not regain miles because he cannot fully charge because he has a 60 KW battery programmed for only 40 KW. The only people who can allow for him to regain battery life is Tesla.

In regards to many of the same replies to this thread - Low rated range is not bad - the battery is simply.. OUT OF BALANCE. In order to regain these miles one must charge to 100%. IT IS NOT GAURANTEED TO REGAIN 'ACTUAL' RATED RANGE THE FIRST TIME ONE CHARGES TO 100%. IT SOMETIMES TAKE 3 DAYS AT 100% TO REGAIN RATED RANGE OR CHARING TO 100% THEN DRIVING DOWN TO 0 THEN DOING IT A FEW MORE TIMES UNTIL YOU WILL BALANCE A PACK.

Charging to 100% does not hurt your battery - it only hurts it when it stays there for a long amount of time.

We can hear you fine in lower case ;-)

 

[kjl]

There is some reason to believe that the displayed drop in rated range (at a fixed SOC) when you routinely charge the battery to only 60 or 70% is a) not reflective of a real drop in range or battery capacity b) not related to charge imbalances, and c) just an artifact of limitations in the algorithm that Tesla uses to estimate the battery's energy capacity. (For what little it's worth, I mostly charge to 60%.) See post 1017 and following on the "Decreasing range thread" for details:

Decreasing rated range. - Page 102

Thanks for the link - that makes me feel better. Although I don't really know anything about batteries, and apparently they are super confusing, it does make sense that charging to 60% would not be "bad" for the battery. Probably the best thing for me to do is go back to charging to 60% and stop worrying about it and stop second guessing myself.

In order to do a FULL balance - one must first charge to 100%

So, I've been lurking on this forum for a while (since I got the car), and I've heard all this talk about pack rebalancing at 100% charge, about how it needs rebalancing, how one should fully charge it to 100% and leave it for an hour or two, etc. and basically took it as fact since everybody seemed in agreement that that was accurate information.

However, given the link that Jeff Miller gave, as well as the info from the service advisor I've been trading emails with who flatly wrote "the battery does not do any kind of rebalancing", I'm going to question my old beliefs. Is there a quote from a Tesla/official source that actually verifies that this 100% pack charge rebalance is a real thing, or is it all just conjecture from owners who noticed that their displayed range sometimes went up after full charges (which would be explainable either with the pack rebalancing hypothesis *or* the hypothesis that the number goes up simply because the car is better able to estimate the battery capacity after a full charge)?

 

[ecarfan]

So, I've been lurking on this forum for a while (since I got the car), and I've heard all this talk about pack rebalancing at 100% charge, about how it needs rebalancing, how one should fully charge it to 100% and leave it for an hour or two, etc. and basically took it as fact since everybody seemed in agreement that that was accurate information.?

Definitely not "everybody".

Is there a quote from a Tesla/official source that actually verifies that this 100% pack charge rebalance is a real thing, or is it all just conjecture from owners who noticed that their displayed range sometimes went up after full charges (which would be explainable either with the pack rebalancing hypothesis *or* the hypothesis that the number goes up simply because the car is better able to estimate the battery capacity after a full charge)?

In my opinion it is largely conjecture. There is a great deal of confusion on this issue and there is a dearth of consistent information from Tesla representatives.

 

[jerry33]

In my opinion it is largely conjecture. There is a great deal of confusion on this issue and there is a dearth of consistent information from Tesla representatives.

There is also a shortage of long-term field data, and it doesn't help that the batteries have had at least three revisions (A, B, and D have been spotted). Most of the data we have is really based on the Roadster, and the assumption is that the Model S will behave similarly (only better).

 

[djp]

Is there a quote from a Tesla/official source that actually verifies that this 100% pack charge rebalance is a real thing, or is it all just conjecture from owners who noticed that their displayed range sometimes went up after full charges (which would be explainable either with the pack rebalancing hypothesis *or* the hypothesis that the number goes up simply because the car is better able to estimate the battery capacity after a full charge)?

The BMS definitely does pack balancing. The battery diagnostic screen shows the state of balance with high bricks in orange and low bricks in green, similar to the max and min brick voltages on the Roadster.

View attachment 42080

We don't know when the balancing happens on the Model S. On the Roadster balancing is done directly after a Standard charge or Range charge completes. The Model S no longer has a Standard mode - it's possible that Tesla removed mid-SOC balancing when they added the charge slider.

We also don't know if the range loss that owners are seeing is a result of the pack being out of balance. It could be an error in the capacity estimate algorithm or some other factor we're not even aware of.

It would be great to get access to the diagnostic screen, or reverse engineer the CAN bus to get some real data. The information coming from Tesla has been spotty or conflicting, which is a big step backwards from the excellent engineering blog they used to write for the Roadster.

 

[Chris Naps]

Like when one charges to 100% and let's the battery stay at the SOC for three days and then repeats that pattern multiple times as you recommend?

And you recommend this based on what factual evidence?

I recommend this based on the factual evidence of the technicians at Tesla. They were the ones that recommended this solution.

There is another person being told the same thing:
> My SCS told me that engineering said: [walla2]

Objection! Your Honor that is hearsay!! . . . Ok, disregard that outburst:

> 1. Charge to 100%. Leave plugged 30 minutes longer. Run down to 20%. Leave 30 minutes and then charge. Repeat 3 times.

> 2. Leave charged to 100% for 3 days without driving.

Now, when you have completed these tasks, Grasshopper, return and you will be issued more convoluted and incomprehensible chores to complete. Drink the Kool Aid, hold your head high, take a walk in the sun . . .
--

 

[jerry33]

I recommend this based on the factual evidence of the technicians at Tesla. They were the ones that recommended this solution.

I'd agree if Tesla recommendations were consistent but they appear to vary a lot so it's not at all clear which recommendations are correct and which are not.

 

[Chris Naps]

I'd agree if Tesla recommendations were consistent but they appear to vary a lot so it's not at all clear which recommendations are correct and which are not.

I totally agree - there really needs to be a "STANDARD" set by Tesla. They should come out and openly state what they know so there isn't any confusion on this.

It is under my opinion that I believe Tesla doesn't even know what the best method of regaining miles is. (There is a way to do it we all know that, but what is the safest or should it be a weekly, monthly, quarterly, half-a-year, every year type of ritual.)

This technology is new and especially experimenting with different chemicals and molecules in the batteries to extend longevity might be tricky. I'm not a scientist and I do not know much about this technology, but I believe Tesla doesn't want to mention a standard for charging besides for certain basics such as (a plugged in Model S is a happy Model S..) or (Do not charge to 100% all the time.) These are pretty common standards and do not go into detail.

I feel by the time gen III comes out - there will be some additional standards that will be confirmed by Tesla because they will have enough information on different types of methods that Model S technicians offer. Each Model S relays information back to Tesla about SOC and charging methods, as well as additional information. As you stated they all say different things, and maybe they will by that time have a generalized way of stating everything that is centered around one main idea and method. (HOPEFULLY)

 

[AmpedRealtor]

In order to do a FULL balance - one must first charge to 100% - The original poster will not regain miles because he cannot fully charge because he has a 60 KW battery programmed for only 40 KW. The only people who can allow for him to regain battery life is Tesla.

In regards to many of the same replies to this thread - Low rated range is not bad - the battery is simply.. OUT OF BALANCE. In order to regain these miles one must charge to 100%. IT IS NOT GAURANTEED TO REGAIN 'ACTUAL' RATED RANGE THE FIRST TIME ONE CHARGES TO 100%. IT SOMETIMES TAKE 3 DAYS AT 100% TO REGAIN RATED RANGE OR CHARING TO 100% THEN DRIVING DOWN TO 0 THEN DOING IT A FEW MORE TIMES UNTIL YOU WILL BALANCE A PACK.

Charging to 100% does not hurt your battery - it only hurts it when it stays there for a long amount of time.

All you are doing by charging to 100% and then driving the car to 0 miles is teaching the algorithm the high and low extremes of your battery. This improves the algorithm's ability to estimate range at any SOC. This is the same calibration technique officially recommended by Apple for its lithium ion laptop batteries. All this does is change the estimated range displayed by the algorithm, but it does not actually recover any miles (they have always been there, just not necessarily displayed). One data point to support this is the one and only time I charged to 100% after six months of ownership. My ideal range was 301 miles and I was able to drive 15 freeway miles at 75 MPH on flat grade before my display dropped by 1 mile. The algorithm clearly has issues.

Instead of jumping through hoops that could degrade your battery long term, why not just wait for Tesla to come up with a solution? After all, battery degradation is specifically excluded from warranty coverage. So anyone who wants to follow the 100% charge/discharge regimen does so at their own risk, and without a safety net from Tesla.

 

[jerry33]

As you stated they all say different things, and maybe they will by that time have a generalized way of stating everything that is centered around one main idea and method. (HOPEFULLY)

Until that time, I'm going with the following:

1. 50% is best for storage. (Based on Roadster storage mode)

2. Driving is best between 93% and 50%. (Heats the batteries less when driving)

3. If you need a range charge--just do it and don't worry about it. If possible, leave it charging for long enough to completely charge the pack. (This may take up to an hour where the App says one minute remaining.)

4. Set the timer so that your charge ends at about the same time as you start to drive. (Allows the pack to sit at the lowest charge level for the longest time)

5. Set the amps at 32 unless you need to charge faster. (Heats the pack less, easier on the grid)

6. When cold, preheat the pack. (Avoids most power and regen limiting)

7. Avoid running down to zero, and if you do start charging ASAP. (Normal LiIon recommendation)

 

[Chris Naps]

One data point to support this is the one and only time I charged to 100% after six months of ownership. My ideal range was 301 miles and I was able to drive 15 freeway miles at 75 MPH on flat grade before my display dropped by 1 mile. The algorithm clearly has issues.

Instead of jumping through hoops that could degrade your battery long term, why not just wait for Tesla to come up with a solution? After all, battery degradation is specifically excluded from warranty coverage. So anyone who wants to follow the 100% charge/discharge regimen does so at their own risk, and without a safety net from Tesla.

Let me ask this question, (I have never tested this, and probably wouldn't want to only if I was near my home or a charging station) if you are right and it is only an "algorithm issue", then technically speaking if you were rated for... 255 miles and it dropped to 245, the car would evidently still have 10 rated miles left over??? If I drove 245 miles would the WARNING: CHARGE NOW! screen pop up, even though 10 more miles were secretly there? (Lets pretend that there was NOT any battery degradation, and only an algorithm issue.)

And for the last part doesn't Tesla warranty the battery up for 70% of degradation (in 8 years time)???

Until that time, I'm going with the following:

1. 50% is best for storage. (Based on Roadster storage mode)

2. Driving is best between 93% and 50%. (Heats the batteries less when driving)

3. If you need a range charge--just do it and don't worry about it. If possible, leave it charging for long enough to completely charge the pack. (This may take up to an hour where the App says one minute remaining.)

4. Set the timer so that your charge ends at about the same time as you start to drive. (Allows the pack to sit at the lowest charge level for the longest time)

5. Set the amps at 32 unless you need to charge faster. (Heats the pack less, easier on the grid)

6. When cold, preheat the pack. (Avoids most power and regen limiting)

7. Avoid running down to zero, and if you do start charging ASAP. (Normal LiIon recommendation)

Excellent pattern. Keep it up and hopefully you will be one of those people that go 15+ years with over 70% of the battery .

 

[rlang59]

And for the last part doesn't Tesla warranty the battery up for 70% of degradation (in 8 years time)???

Not in the official written warranty they don't.