Wiki Sudden Loss Of Range With 2019.16.x Software

[fbitz777]

So it looks like my AP2, November 2016 Model X 75D has been Charge-gated now. That car is on latest firmware. With it's smaller battery, I've now ruled out my Model X for any long distance driving, other than between home and my parents, which is 125 miles with a supercharger at the 75 mile point. I cannot make it, on a 100% charge anymore either. My Full 100% charge is 214 miles. When I bought it, it was 222. That was last april. lost the range with 10.1 firmware.
Even displaying a 100% charge with 214, I cannot make the 120 mile drive on one charge. The lowest consumption with heat off I can get is 450 Wh/mile.
My battery is the new chem, same as my 90D Model S.

I have similar X75D BUT are you sure you did not loose that range after 2019-16 software instead? Charge-gate came later for me
Anyhow mine is at 211mile range but I was able to do a 150mile trip last week in below freezing weather (all highway) below 400 Wh/mi and I was driving at 70mph ...did not have the heat on though.

 

[Droschke]

Washington Post Today:

“My belief is that Tesla is more willing to risk their battery not lasting 8 to 10 years and just dealing with the consequences on the back-end,” said Michael Ramsey, a senior director and analyst specializing in the evolution of the auto industry with Gartner’s CIO Research Group. “Part of their success is related to their willingness to go way past what the industry would normally would do,” he said.

https://www.washingtonpost.com/technology/2020/01/10/tesla-battery-range/

 

[TJtv]

Washington Post Today:

“My belief is that Tesla is more willing to risk their battery not lasting 8 to 10 years and just dealing with the consequences on the back-end,” said Michael Ramsey, a senior director and analyst specializing in the evolution of the auto industry with Gartner’s CIO Research Group. “Part of their success is related to their willingness to go way past what the industry would normally would do,” he said.

https://www.washingtonpost.com/technology/2020/01/10/tesla-battery-range/

That's a very interesting quote, but there are two ways to interpret it:
1)With the knowledge that we on the forums have that the firmware released in the last 2 weeks seems to be flagging batteries as defective and calling them in for service. Interpreted this way, the statement implies that Tesla is now coming around to "doing the right thing" and replacing defective batteries.

2)Without knowing about that latest firmware. Interpreted this way the statement implies that Tesla has just been a big risk taker along, and one of the ways of "dealing with the consequences on the back-end" is the batterygate/chargegate fiasco that they've dumped on owners.

When I first read the quote in your forum post, I interpreted it as being #1. However, when I read the full article I now much more fully believe it to have been printed more in the mood of #2.

 

[Chaserr]

Washington Post Today:

“My belief is that Tesla is more willing to risk their battery not lasting 8 to 10 years and just dealing with the consequences on the back-end,” said Michael Ramsey, a senior director and analyst specializing in the evolution of the auto industry with Gartner’s CIO Research Group. “Part of their success is related to their willingness to go way past what the industry would normally would do,” he said.

https://www.washingtonpost.com/technology/2020/01/10/tesla-battery-range/

That was an exceptionally in depth article covering this problem. Thanks for linking and I''m glad it's seeing some intelligent media coverage. They touched on the fires and exploding batteries but didn't try to lead with scare tactics; it was about the decisions like it should be. Rare in media.

 

[3ry-reset]

I believe this is the smoking gun proof of why Batterygate caps are implemented everyone has been looking for. This is 92% SOC on a car showing 100% 4.2v strings. If this battery was charged to 100% and left parked for a week or two, these cells would heat up and eventually cause a fire.

I don't know if this is @wk057's condition X or not but this is dangerous and if it has happened in multiple cars there should be an immediate recall.

 

[MP3Mike]

I believe this is the smoking gun proof of why Batterygate caps are implemented everyone has been looking for. This is 92% SOC on a car showing 100% 4.2v strings. If this battery was charged to 100% and left parked for a week or two, these cells would heat up and eventually cause a fire.

I don't know if this is @wk057's condition X or not but this is dangerous and if it has happened in multiple cars there should be an immediate recall.

I think that just shows an out-of-balance pack. That is probably why some people are seeing their 100% charges complete before it reports 100%. Some bricks are hitting vMax early and so it has to bleed them down to match the other bricks before it can allow it to be charged more.

 

[Battpower]

I think that just shows an out-of-balance pack. That is probably why some people are seeing their 100% charges complete before it reports 100%. Some bricks are hitting vMax early and so it has to bleed them down to match the other bricks before it can allow it to be charged more.

What battery is this and do we know car spec and fw? Is it agreed / fact that this pack would have charge shuttling rather than bleed resistors? Does that have any bearing on these readings such as how the imbalance came about? (that is if this is just an imbalanced battery.)

 

[Chaserr]

I believe this is the smoking gun proof of why Batterygate caps are implemented everyone has been looking for. This is 92% SOC on a car showing 100% 4.2v strings. If this battery was charged to 100% and left parked for a week or two, these cells would heat up and eventually cause a fire.

I don't know if this is @wk057's condition X or not but this is dangerous and if it has happened in multiple cars there should be an immediate recall.

HOLY #!@!

Can you charge to 100%? or does it stop you from going over 92% A 4.25v charge would mean that firmware's BMS causes fires.

 

[glhs272]

I believe this is the smoking gun proof of why Batterygate caps are implemented everyone has been looking for. This is 92% SOC on a car showing 100% 4.2v strings. If this battery was charged to 100% and left parked for a week or two, these cells would heat up and eventually cause a fire.

I don't know if this is @wk057's condition X or not but this is dangerous and if it has happened in multiple cars there should be an immediate recall.

I am a bit skeptical here, or rather not enough data. First off, I find it hard to believe that Tesla would ever allow the car to continue charging with cells above 4.200 volts. That's a basic functionality of the BMS and can't believe Tesla would do that. Also, from this data we can't tell if these voltages are during charging or after full saturation... It's only showing 17mv of out of balance, not great but not wildly off.

 

[omarsultan]

I think that just shows an out-of-balance pack. That is probably why some people are seeing their 100% charges complete before it reports 100%. Some bricks are hitting vMax early and so it has to bleed them down to match the other bricks before it can allow it to be charged more.

In my case, at least, that second part does not happen. The car will charge to somewhere in the mid-90s, declare itself done, and then stop. Nothing else happens. Even if I I try and restart charging in the morning, nothing happens.

Perhaps I am misunderstanding the role of the BMS, but if some modules hit 100% before others, should it just shut down charging to those modules and continue to charge the ones that are less than 100%?

 

[glhs272]

Perhaps I am misunderstanding the role of the BMS, but if some modules hit 100% before others, should it just shut down charging to those modules and continue to charge the ones that are less than 100%?

I don't think that's possible. The charger is connected to the battery pack as a whole. Each module in series with each other. Charging should halt when the highest cell in the pack reaches Vmax. But remember, the charger should be in constant voltage mode when the cell reaches Vmax, so the current should be falling. Only when the current reaches the minimum value for cutoff should charging stop.

 

[Chaserr]

Perhaps I am misunderstanding the role of the BMS, but if some modules hit 100% before others, should it just shut down charging to those modules and continue to charge the ones that are less than 100%?

You're right. The safe thing to do is stop when any cell reaches 100% so none go over 4.2v.

I want to see if it does go over 4.2v. BMS should protect the cells from this much imbalance too, but that's not as bad as charging over 100%.

If it's an imbalance, it's kind of insane that we still get it with capped batteries. That would mean some cells are reaching 100% when the rest are at ~80% since our indicated 97% is an actual ~61kwh charge capacity.

 

[omarsultan]

You're right. The safe thing to do is stop when any cell reaches 100% so none go over 4.2v.

I want to see if it does go over 4.2v. BMS should protect the cells from this much imbalance too, but that's not as bad as charging over 100%.

If it's an imbalance, it's kind of insane that we still get it with capped batteries. That would mean some cells are reaching 100% when the rest are at ~80% since our indicated 97% is an actual ~61kwh charge capacity.

I should finally have some time this weekend to play with TM-Spy, so will be curious to see what it shows.

 

[Battpower]

You're right. The safe thing to do is stop when any cell reaches 100% so none go over 4.2v.

I want to see if it does go over 4.2v. BMS should protect the cells from this much imbalance too, but that's not as bad as charging over 100%.

If it's an imbalance, it's kind of insane that we still get it with capped batteries. That would mean some cells are reaching 100% when the rest are at ~80% since our indicated 97% is an actual ~61kwh charge capacity.

Can someone please clarify at what level charge shuttling is applied? Between bricks? Do individual cells balance within bricks and bricks balance with other bricks?

Earlier in the thread or somewhere else there was talk of damage due to interrupting charge cycles and some posters said that the BMS was very sofisticated so cells remained balanced throughout all SOC.

glhs272's post shows clearly that cell imbalance has occurred but even so no cell is above 4.2 at the time captured. If the next phase is for the 4.2 cells to somehow become balanced within the brick and then bricks balance with other bricks, then there is nothing too abnormal imo.

However if the next phase is to keep charging pushing cells over 4.2 that is obviously bad news, and just stopping the charge is leaving a lot of unused capacity.

 

[_jal_]

Par

I believe this is the smoking gun proof of why Batterygate caps are implemented everyone has been looking for. This is 92% SOC on a car showing 100% 4.2v strings. If this battery was charged to 100% and left parked for a week or two, these cells would heat up and eventually cause a fire.

I don't know if this is @wk057's condition X or not but this is dangerous and if it has happened in multiple cars there should be an immediate recall.

pardon my ignorance, but can someone explain what we’re looking at here. I see two columns and eight rows. Each cell has a three by two matrix in it. Are those nodes in the cells individual batteries? What are the columns and rows? I

 

[glhs272]

Par

pardon my ignorance, but can someone explain what we’re looking at here. I see two columns and eight rows. Each cell has a three by two matrix in it. Are those nodes in the cells individual batteries? What are the columns and rows? I

This is a visual representation of the entire battery pack. Specifically cell voltages and temperatures. There are 16 modules in this particular battery. This battery must be a 85kwh or 90kwh battery. 60kwh, 70kwh, and 75kwh batteries have 14 modules. Each module has a BMB board which reads cell voltages and has two thermal couples to read cell temperature of one of the cells closet to coolant inlet and one cell close to coolant outlet (T1 & T2). Each module has 6 groups of cells, each group in a series withe each other, for a nominal module voltage of 24volts, 25.2 volts max. At the group level, each group of cells in each module are multiple cells connected in parallel, so they are effectively locked together at the same voltage. Thus you don't need to measure each cell individually, they are all the same. Just measure the paralleled group, as it is effectively one cell. The box around those 6 cell voltages represents the module. Lithium ion cells used in the Tesla pack typically have a maximum cell voltage of 4.2 volts. The orange colors around some of the voltages highlight Cells at max voltage (4.200) and the green color min voltage (4.183) in this case. The red box shows the max cell temp and the blue box shows the min cell temp.

 

[TJtv]

I think many of you are missing the major point of 3ry-reset's picture. Some cells/bricks being charged to 4.200V and others being at 4.183V is reasonably normal. However, the fact that ANY cells are anywhere near 4.200V when SOC=92% is a huge problem.

 

[Gixx1300R]

I believe this is the smoking gun proof of why Batterygate caps are implemented everyone has been looking for. This is 92% SOC on a car showing 100% 4.2v strings. If this battery was charged to 100% and left parked for a week or two, these cells would heat up and eventually cause a fire.

I don't know if this is @wk057's condition X or not but this is dangerous and if it has happened in multiple cars there should be an immediate recall.

Phantom drain would take care of a fully charged pack overnight, even in warm weather

 

[Chaserr]

You think maybe that's why they made phantom drain is so much worse now than before 2019.16?

 

[omarsultan]

OK, curiosity go the better of me and I grabbed some data with TM-Spy over lunch. Help me make sense of the screen grabs.

Things I could figure out:

• Confirmation my 85(77.5) kWh pack is now a 60.5 kWh pack
• The variation on the column heights in the second chart and the spread on the histogram are less than ideal

I could not figure out how to determine Vmax.