-
Want to remove ads? Register an account and login to see fewer ads, and become a Supporting Member to remove almost all ads.
Wiki Sudden Loss Of Range With 2019.16.x Software
- Thread starter Dutchmeeuw
- Start date
Do you have data from that? I have CAN bus data from my car since 2016 and I have never seen the cell voltage go above 4.2. Even before I had CAN bus access, the car used to show the battery voltage on the charge screen during supercharging and it never ever went above 403 Volt which is just under 4.2 per cell (96 bricks in series). If you have data showing it above 4.2 Volt per cell I'd be very surprised.
In my 6.5 years of owning a model S, I have never seen seen the voltage going above 4.2V.
Did you notice the charging voltage change when you were capped? Or just the final voltage after charging was completed?
That's not how you charge a Li-Ion cell. During the initial, constant current (CC) charge phase, you apply <4.2V (typ 3.5V for a dead cell), but don't exceed the max charge rate. As the cell's state of charge increases, you increase the voltage applied until it hits 4.2V, at which point you switch to constant voltage (CV), allowing the charge current to trail off until it drops to the full charge cutoff.
The specsheet for the Panasonic NCR-18650B shows a CC current of 0.3C (975mA on a 3.25Ah cell), a Vmax of 4.2V, and a charge current cuttoff (full charge) of 65mA. At those rates, the CC phase is ~3 hours, and CV phase is another hour.
You NEVER go beyond 4.2V. Bad things® happen if you do.
Thanks for the explanation! As I said, I have no pic from that, it's only from my memory. So maybe wrong remembering. Thats why I asked if someone with firmware before May 2019 can check it.
Bought the car in November 2018. Did my first trials with ScanMyTesla. Was happy until April 2019 and then my battery died. After getting back the car in June I started to document with screenshots, but since then I never saw it again.
islandbayy
Active Member
I'm on Firmware 8.1. I have been a Tesla owner since 2013, and my first was car #9846. 4.2 is the highest. Rarely, you may see 4.21 and those two only during charging. At charging completion, it will drop to 4.19-4.195
Thanks a lot!
With the actual firmware 2020.4.1 I see extremly precise 4,199 to 4,200 and if one cell will see 4,201V the charging is directly stopped. With your firmware I remember to see during charging for longer periods on some cells higher voltages. My imbalance during charging is 80mV. I guess it was to reach on each cell the maximum capacity.
For those affected by #chargegate, here is an observation.
The SCFactor (a.k.a Magic Number which is the sum of the SOC and charge power) varies more at the start of the charge than the end, and has a greater impact on how long your charge session takes.
The starting SCFactor number appears to be primarily a function of the battery temperatureand battery SOC. Temperature becomes less of a factor towards the end of the charge because the battery is being warmed by the charging process itself.
My last three SC charges this week as as follows:
1) 53 min session, 38KWH added, car driven gently from cold (9C) for 15 minutes prior to charging
2) 54 min session, 48KWH added, car driven gently from cold (9C) for 30 minutes prior to charging
3) 60 min session, 58KWH added, car driven hard (10C) for 60 minutes prior to charging
Key: Green line is SOC, Yellow line is Power (KWH) and the Blue line is the SCFactor
Charge 1 Graph
Charge Graph 2
Charge Graph 3
Notice how from halfway through the charge (after ~30 minutes), the SCFactor approaches120 the end SCFactor.
Another metric that might be useful to help compare batteries and supercharging sessions is the number of KWH added per minute over the duration of the charge. These would be my numbers for my last three SC charger sessions:
1) 53 min session, 38KWH added, 0.71 KWH/min
2) 54 min session, 48KWH added, 0.88 KWH/min
3) 60 min session, 58KWH added, 0.96 KWH/min
To improve the metric, it would be better to possibly exclude the first 3 minutes of the charge since that is (usually) much higher than the rest of the session; 125KWH for the start of my 3rd charge session before reducing to ~100KWH
This data is from a 2016 85D with 46k miles and which is voltage capped.
The SCFactor (a.k.a Magic Number which is the sum of the SOC and charge power) varies more at the start of the charge than the end, and has a greater impact on how long your charge session takes.
The starting SCFactor number appears to be primarily a function of the battery temperature
My last three SC charges this week as as follows:
1) 53 min session, 38KWH added, car driven gently from cold (9C) for 15 minutes prior to charging
2) 54 min session, 48KWH added, car driven gently from cold (9C) for 30 minutes prior to charging
3) 60 min session, 58KWH added, car driven hard (10C) for 60 minutes prior to charging
Key: Green line is SOC, Yellow line is Power (KWH) and the Blue line is the SCFactor
Charge 1 Graph
Charge Graph 2
Charge Graph 3
Notice how from halfway through the charge (after ~30 minutes), the SCFactor approaches
Another metric that might be useful to help compare batteries and supercharging sessions is the number of KWH added per minute over the duration of the charge. These would be my numbers for my last three SC charger sessions:
1) 53 min session, 38KWH added, 0.71 KWH/min
2) 54 min session, 48KWH added, 0.88 KWH/min
3) 60 min session, 58KWH added, 0.96 KWH/min
To improve the metric, it would be better to possibly exclude the first 3 minutes of the charge since that is (usually) much higher than the rest of the session; 125KWH for the start of my 3rd charge session before reducing to ~100KWH
This data is from a 2016 85D with 46k miles and which is voltage capped.
Last edited:
thesnooch
Member
Thanks for the help.
I will try to get my battery uncapped. I call SC and keep you posted.
Thank you.
lightningltd
Member
I managed to get a response from service center after creating a appointment from the app.
Today I received a SMS that they will begin a over the air diagnostic. No changes visible yet.
Will keep you posted.
The latest Tesla Service text:
“Thank you for scheduling an appointment , we have reviewed the details and found that this is a normal characteristic of your vehicle. With a recent software update, Tesla has updated the charge profile in the battery management system of some vehicles which can lead to a slight reduction of fast charging peak power. The overall charging time from 10% to 85% is not significantly affected, but peak miles (or km) charged per hours is slightly reduced.
This update helps further protect the battery and improve battery longevity. Based on these results we will cancelling your appointment.”
The point about no significant affect on overall charging time is clearly false.
I also note that the Tesla Tech picked an 85% finishing percentage that would allow Tesla to catch up a bit in the time comparison, though that finishing percentage is beyond the 80% allowable point when the demand for a SuperCharger is high.
The key for long distance travel efficiency had been the time (15 minutes or so) to charge from 10% to 60%, in order to get back out and drive two hours to the next SuperCharger. It appears that Tesla has now programmed our cars to SuperCharge in the time it takes to fill a cart at Costco or eat a three-course meal, which makes cross-country travel infeasible and inter-city travel labourious.
Following a 10,000km road trip from Ottawa to Banff / Yellowstone in 2015 (when there were still substantive gaps in the SuperCharger network), I was essentially a salesman for Tesla. Five years later I am advising potential buyers that they will still require an ICE, as a Tesla vehicle will only be functional for local driving and occasional inter-city travel.
“Thank you for scheduling an appointment , we have reviewed the details and found that this is a normal characteristic of your vehicle. With a recent software update, Tesla has updated the charge profile in the battery management system of some vehicles which can lead to a slight reduction of fast charging peak power. The overall charging time from 10% to 85% is not significantly affected, but peak miles (or km) charged per hours is slightly reduced.
This update helps further protect the battery and improve battery longevity. Based on these results we will cancelling your appointment.”
The point about no significant affect on overall charging time is clearly false.
I also note that the Tesla Tech picked an 85% finishing percentage that would allow Tesla to catch up a bit in the time comparison, though that finishing percentage is beyond the 80% allowable point when the demand for a SuperCharger is high.
The key for long distance travel efficiency had been the time (15 minutes or so) to charge from 10% to 60%, in order to get back out and drive two hours to the next SuperCharger. It appears that Tesla has now programmed our cars to SuperCharge in the time it takes to fill a cart at Costco or eat a three-course meal, which makes cross-country travel infeasible and inter-city travel labourious.
Following a 10,000km road trip from Ottawa to Banff / Yellowstone in 2015 (when there were still substantive gaps in the SuperCharger network), I was essentially a salesman for Tesla. Five years later I am advising potential buyers that they will still require an ICE, as a Tesla vehicle will only be functional for local driving and occasional inter-city travel.
May I ask you to go to a supercharger with a warm battery and charge to 100% and check the charging power in kW and also the min and max voltages of your cells if you are close to 100% ?
My car is on this level only charging with 0...1kW and if the first cell reaches 4.201V the charging stops. After the stop the voltages on this cell falls quickly to 4.19 V and because of imbalance some other cells are in 4.13V. No more trial to get closer to 4.200V on the cells. With your software I remember some kind of pumping to really reach the full charge and also never less than 2...3kW charging power. I agree that the actual way of charging is much better for long life and preventing overcharging but it means a lost of around 10km. Its technically acceptable but sad to have to do such kind of guessing because of no clear statement from Tesla...
That is a brilliant move. If whoever did this is here, post the file. If not, we should do it ourselves and post these to every stall every time we supercharge. If the paper is completely stuck on by clear packing tape it should be perfectly weather proof and hard to remove.
Bravo!
You can't charge any further once a cell group hits 4.2V. All the groups are wired in series. The charge current flows through all of them. Once one is full, you're done. There's no way to continure to charge the other 95 cell groups without overcharging the fullest and risking fire.
Similar threads
