Wiki Sudden Loss Of Range With 2019.16.x Software

[tga]

I don’t know the specific way Tesla does it (though my understanding is that they use off the shelf chips so you can look at the data sheet). There is no need to stop charging when one cell hits 4.2v, you can have a circuit to shunt current around the cell that is full or on more advanced designs you can shunt current from the cell with the highest SoC to the one with the lowest SoC (this is more efficient but more complicated).

That's not how the Tesla BMS works (at least the S/X). See wk057's teardown thread. There are small bleeder resistors that can be turned on to (slowly) drain a parallel group of cells. There is no active shunting around a parallel group to continue charging the others (nor the hardware to do it, regardless of sw updates). Once a parallel group hits 4.2V, charging stops. It can restart once the BMS drains down that high group, but the resistors are small and it will take a while to drain.

I fully agree but as I said I remember some kind of pumping. Means, after reaching 4.200 in one cell you switch off and wait for some balancing and then you can do the next trial to get closer to 4.200V on all cells and not only on one. I mean like stage4 in figure1 of this article https://batteryuniversity.com/learn/article/charging_lithium_ion_batteries

You'll see the car turn on and top off the charger periodically, but it takes a ~3% drop before it kicks in. The bleeder resistors are really small and have limited current capacity, so it'll take a while for the cells to balance. Each parallel group of 74 cells in an original 85kWh pack is around 250Ah; there's a lot of electrons there that need to be turned into heat in a tiny resistor; you can't go very fast.

Wouldn't a possible replacement strategy be that non P models gets the - assumed - 350V pack and P models the refurbed 400V packs? For the same power at 350V as at 400V, the current draw is 15% higher, which could be above what wiring supports.

The 350V pack is OK for RWD P's (320kW max), but maybe not for AWD P's. For example, on my P85+, I've seen 1145A @ 253V (290kW, voltage sags under load) on a partially charged pack at full throttle.

 

[Chaserr]

We already know it's good for P85 - the first known 350v installation was in one. P85D will probably need a new 400V battery though, unless the new 350V can still handle its 400V Ludicrous amp load. Ludicrous amps on the 400V version are 1700, meaning if close to the same amps are possible it can still deliver over 500kW. I don't think that is completely possible without the additional cells though, there has to be some amp loss for safety.

 

[Daniel in SD]

That's not how the Tesla BMS works (at least the S/X). See wk057's teardown thread. There are small bleeder resistors that can be turned on to (slowly) drain a parallel group of cells. There is no active shunting around a parallel group to continue charging the others (nor the hardware to do it, regardless of sw updates). Once a parallel group hits 4.2V, charging stops. It can restart once the BMS drains down that high group, but the resistors are small and it will take a while to drain.

Are you sure the bleeder resistor can't be turned on while still charging? That's what I meant by shunting current around the cell.
Anyway, the end result is the same, you can charge all the cells in the pack to 4.2V.
Here's the relevant page in the teardown: Pics/Info: Inside the battery pack
Sounds like the bleed resistors are very large (small current).

 

[tga]

Are you sure the bleeder resistor can't be turned on while still charging? That's what I meant by shunting current around the cell.
Anyway, the end result is the same, you can charge all the cells in the pack to 4.2V.
Here's the relevant page in the teardown: Pics/Info: Inside the battery pack
Sounds like the bleed resistors are very large (small current).

I haven't read through that thread in a while. In the post below the one you linked (#282), wk057 mentions 20Wh dissipated over an 8 hour charge. So 20/8 or 2.5W (Watts, not kilowatts), so I don't see that could work while charging.

 

[AmpedRealtor]

Does this point to my 12v or my main battery?

 

[islandbayy]

Does this point to my 12v or my main battery?
View attachment 524148

Unfortunately, I believe that may be drive unit problem. Based on the codes provided.

 

[maximizese]

Does this point to my 12v or my main battery?
View attachment 524148

I had those same warnings on my instrument display back in December. I called Tesla Roadside and they advised me to drive to my local Service Center before attempting a reboot. The reboot did not resolve anything, but I was able to get to the SC 30 minutes before they closed. They said they would diagnose the car the following business day. It turns out the warning codes were related to bad HV battery contactors. They replaced the HVAC drain hose while they were at it and replaced my 12V battery; though the 12V battery did not seem to show any signs of fading. I was still getting a >12.5V readout before turning the car on. Finally, they replaced the drive unit because of excessive droning noises.

Hope you get a resolution soon.

 

[JustADude]

Does this point to my 12v or my main battery?
View attachment 524148

I had those errors too. They replaced my rear drive motor twice in a month because of it.

They must have goofed something the first time or the motor was faulty

 

[AmpedRealtor]

Thanks, everyone. Bummer, I was hoping for a new battery! I have a 2013 P85 that is 2,000 miles past my ESA. Not batterygated, but am chargegated. I scheduled service through the app, which isn't for another week. I may just try driving to service with a max of 150kW and no regen lol

 

[Ulrich]

Count me in please.
S85 on it´s second battery (changed @ 120.000km to a equivalent one, minimal better due to much less DC charging).
200k KM Odometer.

Came from 2019.16.1.1 where everything was safe & sound.
Last week force upgrade to 2020.4.1

Old charging rate was ~68KW@ 50%
new one 44KW@ 50%, thats a whopping 40% loss.

Here´s what the Service Center stats, finally seem to be letting the cat out the bag:

"...at the moment the charge power/curve of these models is limited and modified by the software. Unfortunately, we as a service center have no influence here, so it makes no sense for you to come to the workshop."


So from one day to another the car is de-valued and no longer a joy to use on long range trips.
What can I do?

 

[Droschke]

"...at the moment the charge power/curve of these models is limited and modified by the software. Unfortunately, we as a service center have no influence here, so it makes no sense for you to come to the workshop."

Would you post the screenshot of that statement here please (even though it's in German)?

 

[Chaserr]

"...at the moment the charge power/curve of these models is limited and modified by the software. Unfortunately, we as a service center have no influence here, so it makes no sense for you to come to the workshop."

Wow that's circular. "Tesla is limiting your charge speed on purpose, but not us at THIS Tesla location specifically, so pound sand."

At least they're finally honest and aren't just giving the insulting memo about losing weight and drive half the speed limit they lumped in with all my chargegate service requests.

+1 please share a pic of their admission in writing!

 

[ElektroHorst]

Wow that's circular. "Tesla is limiting your charge speed on purpose, but not us at THIS Tesla location specifically, so pound sand."

At least they're finally honest and aren't just giving the insulting memo about losing weight and drive half the speed limit they lumped in with all my chargegate service requests.

+1 please share a pic of their admission in writing!

Please see attached the answer wich I received from my SEC in the south of Germany. We all hope to get our charge speed back !

 

[joltheadq]

Does ludicrous mode accel the death of a dying pack?

 

[Droschke]

Please see attached the answer wich I received from my SEC in the south of Germany. We all hope to get our charge speed back !

Rough translation, curtsy of Google Translate:

"Hello Sir ... the loading speed is heavily dependent on influences. However, the speed of some vehicles was reduced on the supercharger so that the cells are protected. Thanks for being the case here. Nothing else is going to happen here at the moment, and even software won't reverse this. At least nothing is planned here. VG M."

 

[islandbayy]

Does ludicrous mode accel the death of a dying pack?

Yep, sure helps! Launch away and get a new pack!

 

[lightningltd]

Rough translation, curtsy of Google Translate:

"Hello Sir ... the loading speed is heavily dependent on influences. However, the speed of some vehicles was reduced on the supercharger so that the cells are protected. Thanks for being the case here. Nothing else is going to happen here at the moment, and even software won't reverse this. At least nothing is planned here. VG M."

One word comes to mind with this response: EVIDENCE!

 

[T.R.T.e.s.l.a.]

I don't know about you guys, but i'm pretty sure Tesla has been slowly robbing kwh from my battery with the latest "updates".
They just changed their strategy and instead of taking range from us all of a sudden, they just slowly steal it.
It's not degradation, it's a steal!
F**k Tesla!

 

[Keshk]

I don't know about you guys, but i'm pretty sure Tesla has been slowly robbing kwh from my battery with the latest "updates".
They just changed their strategy and instead of taking range from us all of a sudden, they just slowly steal it.
It's not degradation, it's a steal!
F**k Tesla!

Are you reaching this conclusion because you noticed less max miles range, or because what is been displayed as miles is not really miles used to be before

 

[T.R.T.e.s.l.a.]

Are you reaching this conclusion because you noticed less max miles range, or because what is been displayed as miles is not really miles used to be before

I have both, less displayed kms (miles) and less kwh in Nominal and Usable full pack on Scan My Tesla readings.
90% charge in Dec 2018 displayed 342 km range and last time i got 329 km
80% charge in July 2019 displayed 303 km range and last time i got 292 km

But more importantly
I had 74,5 kwh of Nominal full pack in November 2019 and now i only have 73,1