Wiki Sudden Loss Of Range With 2019.16.x Software

[omarsultan]

OK, off-topic, but this is where the smart battery/charging people seem to hang out. .

My wife '16 Model X P90D is magically gaining range while it's parked in the garage. Here are the records from TeslaFi:

Between 6:53am and 6:54am, the vehicle magically gains 13 miles of range. The car had finished charging at 6:36am. This is the second time this has happened. Ideas?

 

[Droschke]

OK, off-topic, but this is where the smart battery/charging people seem to hang out. .

My wife '16 Model X P90D is magically gaining range while it's parked in the garage. Here are the records from TeslaFi:

View attachment 499449

Between 6:53am and 6:54am, the vehicle magically gains 13 miles of range. The car had finished charging at 6:36am. This is the second time this has happened. Ideas?

Those are part of my lost miles. I would like them back please

 

[JustADude]

I just did the whole efficiency calculation on my 2015 s70d.

Says my battery is at 60.7kw
Vehicle has 192,000km
Had refurb battery installed at 154,000km last July.

Supercharging is really slow.
Does this sound like capping?
Hopefully I get the replace battery message and I can get one unaffected by this stuff.

 

[Dax279]

Thanks for everyone”s comments. One thing I forgot to mention is that my cat is in a heated garage and I set the temperature in the garage at around 10 degrees and so I don’t know why my car would need the battery to be warmed while I am charging?

I also do try to schedule my charging to finish around the time I leave, but will need to adjust for my lazier start to the day this New Year ( still not eager to get up and out yet since the holiday).

 

[omarsultan]

Those are part of my lost miles. I would like them back please

LOL

I thought it ironic that my car is magically losing miles and my wife's is magically finding them.

 

[Droschke]

I just did the whole efficiency calculation on my 2015 s70d.

Says my battery is at 60.7kw
Vehicle has 192,000km
Had refurb battery installed at 154,000km last July.

Supercharging is really slow.
Does this sound like capping?
Hopefully I get the replace battery message and I can get one unaffected by this stuff.

In case you have not read the post#1 of this thread, please do so. There is a link to a "GOOGLE SHEET TRACKER". Plug in your numbers and see what the columns "H" and "I" calculate for you. Compare yourself to others.

FYI, for 75/75D, when new: 75 kWh total capacity, 72.6 kWh usable

 

[Droschke]

Thanks for everyone”s comments. One thing I forgot to mention is that my cat is in a heated garage and I set the temperature in the garage at around 10 degrees and so I don’t know why my car would need the battery to be warmed while I am charging?

I also do try to schedule my charging to finish around the time I leave, but will need to adjust for my lazier start to the day this New Year ( still not eager to get up and out yet since the holiday).

I don't think 10 degrees (I suppose you mean centigrade) is warm enough for the battery at this time per Tesla's new firmware.

 

[Droschke]

LOL

I thought it ironic that my car is magically losing miles and my wife's is magically finding them.

Ah, OK. In that case those must be yours. Somehow wives are good at finding what husbands lose

 

[supratachophobia]

OK, off-topic, but this is where the smart battery/charging people seem to hang out. .

My wife '16 Model X P90D is magically gaining range while it's parked in the garage. Here are the records from TeslaFi:

View attachment 499449

Between 6:53am and 6:54am, the vehicle magically gains 13 miles of range. The car had finished charging at 6:36am. This is the second time this has happened. Ideas?

I've been tracking the same issue with my 90D. Here is how the conversation is going from the cars POV:

" Holy crap, we've been driving around and I've been telling the owner that they can use that bottom 4kw buffer in the battery, because that's what I used to get my EPA rating. But that idiot doesn't realize that zero on the dash board actually means he should stop driving and that they can't actually use that 4kwh. When he isn't looking, I'm going to subtract away those miles so my numbers look right at 0%. I mean, who am I kidding, I'm totally unsafe to drive at such low SOC, it's a miracle the EPA didn't realize that near the end of the test cycle."

Fast forward to your next charge cycle. The car is sitting there thinking:

"Sure is nice to be getting charged up. Just another hour or so to get from 95 to 100%..... Oh s*&#, didn't I tell that owner that they couldn't use that bottom 4kwh so I subtracted that mileage? Let me add it back in real quick to the calculation. Hey, what do you know, I'm back at my full rated range now, I'm all done charging. I'd better tell the app."

 

[gmo43]

My buddy is experiencing this battery issue too and this is this is what his app is showing when he changes the “charge to” slider. Anyone else?

Just tried it myself and I have never been able to charge it to what it says when I move the slider! Lol f-n Tesla they got jokes. Maybe if they remove my cap I would get that if not more.

 

[rowdy]

OK, off-topic, but this is where the smart battery/charging people seem to hang out. .

My wife '16 Model X P90D is magically gaining range while it's parked in the garage. Here are the records from TeslaFi:

Between 6:53am and 6:54am, the vehicle magically gains 13 miles of range. The car had finished charging at 6:36am. This is the second time this has happened. Ideas?

Probably temperature. After you've finished charging the battery pack then starts to cool down and the voltage of the individual cells rise. If the car is using voltage as the main guestimate for SOC then it'll rise as the voltage rises.

I think it's no coincidence that the fires started happening right after Tesla enabled battery heating on way to superchargers.

March - New firmware that heats battery to 45 degrees (celsius) on route to supercharger
April - Cars start bursting into flames left right and centre
May - Emergency update and start of batterygate/chargegate

I think the BMS failed to take into consideration the higher temperature of the cells and this caused the cells to be overcharged. A hot cell will have a lower voltage for the same SOC. If the BMS doesn't properly account for this it'll think the cell is still good for charging when it's actually at capacity. Then you get fires in a worst case. Or damaged modules in a better case

I think all these people complaining about their car only charging to 95% or 97% should be aware that the old firmwares were letting them charge to 100% (which may have actually been 103% or 105% for some modules in the pack).

All my speculation of course. Will be interested to look back on this in a year when we know more from NHTSA and/or court.

 

[Widgeon]

OK, off-topic, but this is where the smart battery/charging people seem to hang out. .

My wife '16 Model X P90D is magically gaining range while it's parked in the garage. Here are the records from TeslaFi:

View attachment 499449

Between 6:53am and 6:54am, the vehicle magically gains 13 miles of range. The car had finished charging at 6:36am. This is the second time this has happened. Ideas?

My P85+ has been exhibiting similar behaviors gaining 7 miles of range over night. Personally I think this has nothing to do with temperature or otherwise and has everything to do with the "Shuttling balancing" we are seeing with newer firmware revisions. Your total battery capacity is determined by the weakest module in the pack. As your car will shutdown once one of the cells inside the module hits 2.5v or the 4kwh buffer is depleted, the BMS determines total capacity not by an average of all the modules, but by the weakest cell in each of the modules (as far as im aware). I think this gaining of miles overnight is due to the "shuttling" of higher voltage cells to the lower cells, effectively making those "bad" cells charged again and thus the total capacity of the pack (as the BMS thinks) is higher. Obviously the cells arent gaining miles of range out of thin air, and I previously have not seen this type of behavior owning the car for 3+ years.

 

[JRP3]

Probably temperature. After you've finished charging the battery pack then starts to cool down and the voltage of the individual cells rise. If the car is using voltage as the main guestimate for SOC then it'll rise as the voltage rises.

Voltage won't rise without current flowing into a cell.

 

[Ferrycraigs]

Probably temperature. After you've finished charging the battery pack then starts to cool down and the voltage of the individual cells rise. If the car is using voltage as the main guestimate for SOC then it'll rise as the voltage rises.

I think it's no coincidence that the fires started happening right after Tesla enabled battery heating on way to superchargers.

March - New firmware that heats battery to 45 degrees (celsius) on route to supercharger
April - Cars start bursting into flames left right and centre
May - Emergency update and start of batterygate/chargegate

I think the BMS failed to take into consideration the higher temperature of the cells and this caused the cells to be overcharged. A hot cell will have a lower voltage for the same SOC. If the BMS doesn't properly account for this it'll think the cell is still good for charging when it's actually at capacity. Then you get fires in a worst case. Or damaged modules in a better case

I think all these people complaining about their car only charging to 95% or 97% should be aware that the old firmwares were letting them charge to 100% (which may have actually been 103% or 105% for some modules in the pack).

All my speculation of course. Will be interested to look back on this in a year when we know more from NHTSA and/or court.

I like the sound of all of that. There’s a but. But my car has been capped. My 70 is now 60.9kWhs. My new 100% was my old 85%. But if I select 100% as the charge limit, it won’t go above 98%. It once stopped at 96%. So once again, my car seems to be one of the exceptions (I only ever charged to 100% once per year, I operated normally between 20-85%, I used slower 50 kW Rapid chargers in preference to 120 kW Superchargers, I never left my car at a high State if Charge) but still got batterygated and chargegated. So I’m sure there will be a reason that some cars will no longer charge beyond 98%, I’m just not sure what that reason is.

 

[Ferrycraigs]

Voltage won't rise without current flowing into a cell.

It’s a long time since my chemistry lessons but I thought it was the current that was affected by temperature. Lower temp, lower current, less power, lower range. So a cold battery gives less range. That doesn’t really help explain Omar's situation.

 

[Droschke]

My P85+ has been exhibiting similar behaviors gaining 7 miles of range over night. Personally I think this has nothing to do with temperature or otherwise and has everything to do with the "Shuttling balancing" we are seeing with newer firmware revisions. Your total battery capacity is determined by the weakest module in the pack. As your car will shutdown once one of the cells inside the module hits 2.5v or the 4kwh buffer is depleted, the BMS determines total capacity not by an average of all the modules, but by the weakest cell in each of the modules (as far as im aware). I think this gaining of miles overnight is due to the "shuttling" of higher voltage cells to the lower cells, effectively making those "bad" cells charged again and thus the total capacity of the pack (as the BMS thinks) is higher. Obviously the cells arent gaining miles of range out of thin air, and I previously have not seen this type of behavior owning the car for 3+ years.

Isn't this "shuttling" only valid for newer cars and not the older cars?

 

[JRP3]

It’s a long time since my chemistry lessons but I thought it was the current that was affected by temperature. Lower temp, lower current, less power, lower range. So a cold battery gives less range. That doesn’t really help explain Omar's situation.

Cold increase the internal resistance of a cell so the voltage when charging will show higher at a given current. Voltage will not rise after charging if the cell cools down.

 

[Droschke]

I think it's no coincidence that the fires started happening right after Tesla enabled battery heating on way to superchargers.

My vote is for coincidence.

 

[Battpower]

Isn't this "shuttling" only valid for newer cars and not the older cars?

I'm trying to understand this. I've seen posts comparing resistive bleed balancing with active charge shuttling, but I haven't managed to find real battery tear-downs showing actual components. Also, the idea of a system keeping cells balanced at all SoC's seems possibly self contradictory because to my mind the idea of balance requires a slow / gentle balance period leading up to a specific desired SOC.

IE: cells (or rather bricks I think - in the case of Tesla, as I don't see how individual parallel cells in a brick get balanced) could be balanced at any predetermined SoC but it would require a specific period of balancing leading up to that SoC that would not guarantee further charging would maintain balance at all SoC's. I know that cells in parallel obviously have the same terminal voltage, but I do not believe that this means that those cells are therefore balanced. A steady constant voltage charge phase is when the cells get chance to balance and I can't see how you make that happen in no time (as in 'cells always kept balanced').

If charging is actually made up of continuous discreet balancing processes then I guess that would work, but I haven't yet found evidence of this.

 

[JRP3]

Cells in parallel act as a single cell and don't need balancing.