Recalibrating the battery

[Greengolfer]

Hello all,
I have been told by the people at my service center that my battery needs to be recalibrated as my car doesn't "see" all of the range that it actually has. I have followed all of the procedures that they have suggested and nothing has worked so far. Does anyone know if powering down the car(following the guidelines in the owners manual) will possibly help? I could really use the range that is hidden a couple of times a month. I would also like to have the range back as I am trying to sell my car in order to upgrade I have a 2014 Model S P85.
Thanks

 

[SSedan]

In the past year Tesla has lowered the voltage limit taking 10-15miles of real range from many of the 85 cars.

How bad is your 100%?
Far as recalibrating the Battery Management System, drain it below 10% and recharge to at least 90% a few times and if the range doesn't return, it is a "batterygate" issue where it is deliberately capped lower than it was before.

You will likely find your supercharging speeds dramatically cut some are reporting 70kw the new cap down from 120kw.

 

[Greengolfer]

I believe that I am a victim of "batterygate." Last spring my range at 90% dropped from ~230 miles to ~210 miles. Since then it has continued to drop significantly. I have tried draining and recharging. No improvement so far. Tesla service it might take several cycles, but five cycles in, no improvement. That is why I was wondering if a powering the off might help.

 

[rooter]

If what they mean is the pack modules are -unbalanced-, balancing does not start until the charge is above 93%.

Set it to 100% and let it charge for at least 24 hours.

 

[2101Guy]

If what they mean is the pack modules are -unbalanced-, balancing does not start until the charge is above 93%.

Set it to 100% and let it charge for at least 24 hours.

Is there a recommended frequency interval for balancing? (ie, every 30th charge cycle should be set to 95% to allow complete balancing to occur)

 

[ucmndd]

Power off isn’t going to do anything.

Nor is anything else for that matter. You’re getting the standard runaround from the service center hoping you give up and go away.

 

[DirtyT3sla]

In my experience calibrating does nothing:

It seems Tesla just tells people to do this to keep them busy :/

 

[ewoodrick]

Running to low state doesn't help. That's a holdover from the NiCad days. The batteries do need periodic balancing and after balancing, the car will recalibrate what 100% is. Keep at 100% for a few days.

But that's all just indicated range. Real range varies with speed and conditions.

 

[Geek190]

Do you have tmspy or Scan My Tesla?
That's going to tell you if you've been voltage capped or not.

I also believe that the rebalancing act that Tesla service says to do is a run-around to get you to leave.

 

[David29]

Hello all,
I have been told by the people at my service center that my battery needs to be recalibrated as my car doesn't "see" all of the range that it actually has. I have followed all of the procedures that they have suggested and nothing has worked so far. Does anyone know if powering down the car(following the guidelines in the owners manual) will possibly help? I could really use the range that is hidden a couple of times a month. I would also like to have the range back as I am trying to sell my car in order to upgrade I have a 2014 Model S P85.
Thanks

Curious, what exactly are the procedures the SC told you to follow?

 

[PWlakewood]

The BMS takes care of managing the battery.

 

[Naekuh]

The BMS controls the level of charge across all Li-ion batteries.
This is why Li-ions all require a BMS, when dealing with multi cells.
The BMS also prevents overcharging on one of the cells, if one should be dead, and saves you from fires.

I dont see how running the battery to near empty and then full again will work when thats an old nicad route which had memory.
We lost this dead leg when Ni-Cad got phased out to NiMH.

Li-ion charging especially on Multi cells, is all dependant on BMS.
So unless u can reset the BMS, or reprogram it directly, there is no calibration.

 

[Alysashley79]

Curious, what exactly are the procedures the SC told you to follow?

My service center told me to try two things.
1)charge the battery down to 5% then up to 90% and allow it to sit at 90% for a minimum of 3 hours after I get charge complete
Rinse. Wash. Repeat.
2)charge battery down to 5% and then max charge the car. Do not unplu until you receive charging complete.

ive done the above and went from max charge at 98% to 99% so I do think there is a method to their madness.

the tech told me that Tesla’s prefer Tesla chargers be it hpwc. Umc. Or SC. They tend to unbalance easier when charging on non Tesla. (Is L2). I do 90% of my charging on L2 because my husbands work provides it free of charge to employees. I’ve owned the car since May 19 and have charged 3400kwh on L2 and less than 500 on Tesla.

 

[rooter]

Is there a recommended frequency interval for balancing? (ie, every 30th charge cycle should be set to 95% to allow complete balancing to occur)

There isn't a recommended interval. What I know about this is due to hacking efforts, and it begins balancing at 93%. I charge mine to 100% about every six months or so, for balancing.

One of these third-party apps will actually graph the state of each module, clearly giving the condition of balancing. Don't remember which one.

The rationale of draining the pack all the way down and charging all the way up is to calibrate its capacity accurately. When it finds the bottom and the top your charge state reading is more accurate. Has nothing to do with lost capacity. An unbalanced pack does though.

 

[amiral_sub]

never let a battery charged at 100% for a long time

 

[Battpower]

If what they mean is the pack modules are -unbalanced-, balancing does not start until the charge is above 93%.

Set it to 100% and let it charge for at least 24 hours.

Where is this information coming from?

There are many posts discussing battery management. The best informed seem to concur that the BMS keeps cells balanced throughout the charge range, and that unlike basic passive balancing, Tesla have active balancing that continuously bleeds charge from cells with highest charge to allow cells with lower soc to 'catch up'.

I have not been able to get to the bottom of a more efficient system allegedly used in some (?newer) cars that shuttles excess charge from cells to maintain balance. Neither have I seen evidence of the battery components that actually bleed off energy. Some pictures show small resistors, but I can't believe that even a few watts of dissipation could do much to get imbalanced cells back to a more balanced state.

Somewhere I read about motor stator windings being used to dissipate energy which is at least capable of dissipating significant amounts of energy. And that heat could also contribute to battery pre-heating, although if cells are kept in balance, there won't be much to do to keep that balance.

In general use it is likely (inevitable ) that gentle (L2 / ac ) charging, moderate ambient temperatures and moderate discharge rates (careful low acceleration / deceleration driving) promote good cell balance, maximum energy storage and longest battery life. Certain use patterns (I forget which, but for example many short journeys at high SOC) can cause BMS to estimate range poorly. So you can have a perfectly balanced battery in good shape that at some time may report lower mileage range.

I have heard no evidence that allowing car to charge above a certain percentage or discharge below a particular limit helps balance or capacity. In fact, being able to set your desired maximum charge would potentially mean that cells never got ballanced if they balance only at high soc.

 

[David29]

Where is this information coming from?

There are many posts discussing battery management. The best informed seem to concur that the BMS keeps cells balanced throughout the charge range, and that unlike basic passive balancing, Tesla have active balancing that continuously bleeds charge from cells with highest charge to allow cells with lower soc to 'catch up'.

I have not been able to get to the bottom of a more efficient system allegedly used in some (?newer) cars that shuttles excess charge from cells to maintain balance. Neither have I seen evidence of the battery components that actually bleed off energy. Some pictures show small resistors, but I can't believe that even a few watts of dissipation could do much to get imbalanced cells back to a more balanced state.

Somewhere I read about motor stator windings being used to dissipate energy which is at least capable of dissipating significant amounts of energy. And that heat could also contribute to battery pre-heating, although if cells are kept in balance, there won't be much to do to keep that balance.

In general use it is likely (inevitable ) that gentle (L2 / ac ) charging, moderate ambient temperatures and moderate discharge rates (careful low acceleration / deceleration driving) promote good cell balance, maximum energy storage and longest battery life. Certain use patterns (I forget which, but for example many short journeys at high SOC) can cause BMS to estimate range poorly. So you can have a perfectly balanced battery in good shape that at some time may report lower mileage range.

I have heard no evidence that allowing car to charge above a certain percentage or discharge below a particular limit helps balance or capacity. In fact, being able to set your desired maximum charge would potentially mean that cells never got ballanced if they balance only at high soc.

Right. it always bothers me that there are a lot of opinions expressed here and elsewhere by people who seem to know something about the proper care and feeding of the battery, but they disagree. Most troubling, Tesla never puts any similar advice in writing. I am leery of self-appointed experts because I have no way to know which of them is truly knowledgeable enough (and no offense intended to anyone). I have so far decided that if Tesla does not tell me to do anything, i don't have to or should not. I wonder if the Tesla techs the OP spoke with actually have some written guidance from the head office, or if they too are working from accumulated hearsay knowledge. It is very worrisome to have such an expensive car and have such a vital component, the big battery, and have so many conflicting statements about how to care for it.....

 

[Alysashley79]

never let a battery charged at 100% for a long time

I think you meant never LEAVE a 100% charged battery for a long time. Service center told me no more than 60 minutes when I asked.

I think the poster may have meant to turn down the amperage you charge at so it trickle charges it’s way to 100%. There was some speculation back in the day that slooooly charging would balance the battery vs just letting it do its thing. Maybe yes back in the day but now it’s not neccesssary at least according to the SC

 

[Geek190]

A couple of months back when I took the car in for service, I complained to the service advisor that my range was slowly dropping. I told him that I'd recently tried running it down to 1%, back to 100%, down to 5%, back to 100%, and then down to a reasonable 80ish%. I told him that it made no difference whatsoever.

He then told me that you are supposed to let it sit for 1-2 hours at each of those charge levels for it to work properly.

I haven't been able to test it out again with the long pauses. I got the feeling that he wasn't really so sure that it would do anything. I also felt that he might have been regurgitating hearsay like David29 posits.

 

[rooter]

Where is this information coming from?

There are many posts discussing battery management. The best informed seem to concur that the BMS keeps cells balanced throughout the charge range, and that unlike basic passive balancing, Tesla have active balancing that continuously bleeds charge from cells with highest charge to allow cells with lower soc to 'catch up'.

I have not been able to get to the bottom of a more efficient system allegedly used in some (?newer) cars that shuttles excess charge from cells to maintain balance. Neither have I seen evidence of the battery components that actually bleed off energy. Some pictures show small resistors, but I can't believe that even a few watts of dissipation could do much to get imbalanced cells back to a more balanced state.

Somewhere I read about motor stator windings being used to dissipate energy which is at least capable of dissipating significant amounts of energy. And that heat could also contribute to battery pre-heating, although if cells are kept in balance, there won't be much to do to keep that balance.

In general use it is likely (inevitable ) that gentle (L2 / ac ) charging, moderate ambient temperatures and moderate discharge rates (careful low acceleration / deceleration driving) promote good cell balance, maximum energy storage and longest battery life. Certain use patterns (I forget which, but for example many short journeys at high SOC) can cause BMS to estimate range poorly. So you can have a perfectly balanced battery in good shape that at some time may report lower mileage range.

I have heard no evidence that allowing car to charge above a certain percentage or discharge below a particular limit helps balance or capacity. In fact, being able to set your desired maximum charge would potentially mean that cells never got ballanced if they balance only at high soc.

"Where is this information coming from?" You will just have to take my word for it (or not). I am not going to any trouble to prove it if this is how people are. (And learn how to spell 'balanced')

Right. it always bothers me that there are a lot of opinions expressed here and elsewhere by people who seem to know something about the proper care and feeding of the battery, but they disagree. Most troubling, Tesla never puts any similar advice in writing. I am leery of self-appointed experts because I have no way to know which of them is truly knowledgeable enough (and no offense intended to anyone). I have so far decided that if Tesla does not tell me to do anything, i don't have to or should not. I wonder if the Tesla techs the OP spoke with actually have some written guidance from the head office, or if they too are working from accumulated hearsay knowledge. It is very worrisome to have such an expensive car and have such a vital component, the big battery, and have so many conflicting statements about how to care for it.....

"self-appointed experts"? See, this is what I get for trying to help ignorant people.

Gourd head and follow your unbased theories and continue to get your terrible results. Rest assured, I won't care. Too bad I can't go back and undo my attempt to help you. All I can do is refrain in the future.

Ignore mode enabled.