Welcome to Tesla Motors Club
Discuss Tesla's Model S, Model 3, Model X, Model Y, Cybertruck, Roadster and More.
Register

Wiki Sudden Loss Of Range With 2019.16.x Software

This site may earn commission on affiliate links.
I’m a new owner here with a pre-Raven 2019 purchased two months ago so I am not up to speed on degradation. Is this in any way related to mileage? Meaning that I see many people with higher mileage who claim to be unaffected, while low mileage owners seem to be disproportionately affected?
 
Vmax in any context is just the specified maximum voltage a given component is supposed to be capable of taking; anything beyond that risks damaging the component and/or voiding the warranty. In the context of a battery, it is the maximum cell voltage allowed within specification — at which point that cell is 100% charged; in the context of the BMS, it's a software-imposed limitation(/calculation) — above which the BMS will refuse to charge (and at which the BMS declares 100% charge). By default, the BMS will limit the charge voltage to match the cell's specification; under certain circumstances (such as corked battery packs for SKUing purposes and/or "out of an abundance of caution"), the BMS will restrict the voltage to a lower value — but that doesn't change the inherent specification of the cell, it just leaves that portion of the cell unused.

TL;DR: 4.07 V is still an 87% charge at the cell level, but 100% according to the BMS (and would be 115% at 4.2 V if one could manually charge beyond the BMS's self-imposed limit).
Many thanks. That is all very clear and I now understand where I was getting it wrong. I had presumed, incorrectly, that capping (as in a 60 being a capped 75) was a bit like the buffer, as in its there but not available. I now understand capping and batterygate is all done by limiting the cell voltage. Which I assume also means if someone has lost range but is still at 4.2V, that’s degradation not due to the software update.

Question. How do they make the buffer unavailable as I presume this is done a different way. (not a trick question, just trying to educate myself)
 
Question. How do they make the buffer unavailable as I presume this is done a different way. (not a trick question, just trying to educate myself)
By "the buffer", I presume you're referring to the additional amount of charge that every pack can contain but that the car cannot use; that is achieved by reserving approximately 5% of the cells' capacity above Vmin to ensure the cells don't bottom out (once a lithium ion cell reaches a certain voltage below Vmin, it's effectively bricked). This forum has more information.
 
  • Informative
Reactions: Ferrycraigs
By "the buffer", I presume you're referring to the additional amount of charge that every pack can contain but that the car cannot use; that is achieved by reserving approximately 5% of the cells' capacity above Vmin to ensure the cells don't bottom out (once a lithium ion cell reaches a certain voltage below Vmin, it's effectively bricked). This forum has more information.
Thanks again. Very helpful.
 
I’ve been complaining to Tesla since June 20 that I had a battery issue. Prior to June 20, I had 74kWh battery capacity under ver 8.1. My car was forcefully updated to ver 9, and my battery capacity started decreasing 1-2kWh each time I charged to it was 66kWh capacity about 3 weeks latter. I had the West Palm Beach FL service center and Rockville MD service center look into the matter and each said the logs show nothing and it’s normal degradation (which I didn’t buy).

I’m in the Boston MA area today and the car is dead with several warnings on the instrument cluster about the battery voltage being below normal, power being reduced, pull over immediately (kinda funny as I was trying to shift the car from park into drive), etc. Called Tesla 877 number and they told me the system shows I have a battery issue (not the 12 volt battery but the HV battery). They have arranged for a tow truck to get my car.

Morale, you know your car better than Tesla. Don’t take their word that there is nothing wrong with the battery if you suspect there is an issue.

Will update when I find out more. I hope I get a loaner car, I have medical appointments in Boston the next two days and need to be in FL on August 14 to see my son who is flying in from out of the country.
 
Last edited:
I’ve been complain to Tesla since June 20 that I had a battery issue. Prior to June 20, I had 74kWh battery capacity under ver 8.1. My car was forcefully updated to ver 9, and my battery capacity started decreasing 1-2kWh each time I charged to it was 66kWh capacity about 3 weeks latter. I had the West Palm Beach FL service center and Rockville MD service center log into the matter and each said the logs show nothing and it’s normal degradation (which I didn’t buy).

I’m in the Boston MA area today and the car is dead with several warnings on the instrument cluster about the battery voltage being below normal, power being reduced, pull over immediately (kinda funny as I was trying to shift the car from park into drive), etc. Called Tesla 877 number and they told me the system shows I have a battery issue (not the 12 volt battery but the HV battery). They have arranged for a tow truck to get my car.

Morale, you know your car better than Tesla. Don’t take their word that there is nothing wrong with the battery if you suspect there is an issue.

Will update when I find out more. I hope I get a loaner car, I have medical appointments in Boston the next two days and need to be in FL on August 14 to see my son who is flying in from out of the country.

What year is your car, model, and miles? This is very concerning especially if they tested the batter recently. Sorry that happened to you must suck. Obviously they didn't give you any sort of print out on battery health either did they?
 
If it's helpful to anyone I'd be happy to try to repeat that process. I'm no longer intetested in updates. Of course I have no idea when that might be.

Wifi-enabled wifi and got an update. I started it immediately.

First screen is "starting update". Car would drive and I went for a 10 minute drive - message remained.

About 20 minutes into the update (now parked) received a message saying the update failed. But the update was still staged and I restarted it.

Now the message changed to "update in progress'. Again I could drive without affecting the update.

Back parked and watching, the screen changed to "car off" and the MCU was unresponsive - no "update" message. The MCU rebooted twice. Car will now not restart but MCU is on, but unresponsive. I can still hear various components making noise. I can still connect with the app which says "installing update".

Another 20 minutes and I get an error that says "software update required, contact service". But the software tab also says "downloading navigation update".

So I guess this is debunked - doesn't sound like a reliable means to defer an update. Sorry.
 
What year is your car, model, and miles? This is very concerning especially if they tested the batter recently. Sorry that happened to you must suck. Obviously they didn't give you any sort of print out on battery health either did they?

It is a 2013 P85 Model S with about 62K miles. Original owner. Still waiting for the tow truck to arrive.
 
  • Like
Reactions: gmo43
The car was forcefully updated by Tesla without my acceptance on June 20. That is when the problems started. Currently on 2019.24.1.5. I went from a 74kWh usable capacity to 66kWh usable capacity last week. Not sure what it is today. Can’t connect to the car.
 
  • Informative
Reactions: Droschke
Excessive lithium plating on the anode in the form of dendrites seems to be a problem associated with charging (incl. regenerative charging) of relatively cold batteries. That probably explains why some otherwise similarly treated cars are affected and others not. I expect there are more victims here in northern Europe and in Canada than there are in Ca.
 
  • Informative
Reactions: David99
The car was forcefully updated by Tesla without my acceptance on June 20. That is when the problems started. Currently on 2019.24.1.5. I went from a 74kWh usable capacity to 66kWh usable capacity last week. Not sure what it is today. Can’t connect to the car.

You are impacted. But looks like you might have a separate but serious issue with your now shrunken HV battery. Insist for replacement.
 
  • Like
Reactions: mjmiron
Excessive lithium plating on the anode in the form of dendrites seems to be a problem associated with charging (incl. regenerative charging) of relatively cold batteries. That probably explains why some otherwise similarly treated cars are affected and others not. I expect there are more victims here in northern Europe and in Canada than there are in Ca.

U2 ;) impacted?