Wiki Sudden Loss Of Range With 2019.16.x Software

[CuriousG]

So the last 3 charged it has maintained 23 miles lost. After getting airbags replaced, I had to ask for the notes the person read to me the other day. Service rep copy and pasted it in an e-mail.

Me: Severe battery degradation within last month. Lost mileage every time I’ve charged since I noticed a severe drop in range. So far within last month lost at least 23 miles.

Pre-Diag: There are no HV battery faults. The decrease in range is due to the increase in ambient heat. The Battery management system has recalculated the range to compensate for the energy it has to consume to cool the battery and drive unit(s) in hot weather.

So checking on my TeslaFi log I was already losing range when it wasn't hot yet so that's a bunch of BS. It wasn't until recently it got hot. I even asked the person (not tech) that does that mean I'll start gaining some miles lost when it gets cool again? I already know the answer to that. If this was true, I would have noticed higher than normal degradation the last two summers.

I'm not sure if this is specific to this service center (Rocklin) but they don't even wash cars now because of how overwhelmed they are from new deliveries and those take priority.

 

[electronblue]

@DJRas

Anyway, FWIW here is Tesla saying they are pushing a software update due to the battery fires:

Tesla pushes battery software update after recent fires

 

[geofunner]

I'll charge to 90% this evening or tomorrow morning and if I notice anything suspect I'll reach out to you. 2015 S85 30K miles. Battery 1064362-00-A.

Doesn't appear that I'm a good data point. After combination supercharge/home charge to 90% My S85 is @ 238 rated miles.

I have been at 16.2 roughly since it went wide.

 

[Droschke]

No. You still mix up capacity and SOC.

100% SOC is always 4.2V. New, after 50'000 miles, after 500'000 miles. Always.

Capacity goes down over time.

You have a usable capacity between about 4.2V and 3.5V. When a cell is new you can use f.e. 3000 mAh. Now your cell gets older and degrades to 2000 mAh. You still load your cell to 4.2V and discharge to 3.5V. Like new. But get only 2000 mAh instead of 3000 mAh.

Now tesla limits Vmax to 4.1V. Then you have only about 85% left from your reduced capacity. So 2000 * 0.85 = 1700 mAh.

Thank you Gizmo for stating the facts.

It does not matter because someone can be "versed in electrical engineering" and have this point of view "If people don’t want Tesla messing with their vehicle operation, then disconnect the vehicle from the internet and avoid the updates. Every Tesla owner knows that updates can increase or decrease performance. It’s part of the Tesla experience."

 

[VT_EE]

No. You still mix up capacity and SOC.

100% SOC is always 4.2V. New, after 50'000 miles, after 500'000 miles. Always.

Capacity goes down over time.

You have a usable capacity between about 4.2V and 3.5V. When a cell is new you can use f.e. 3000 mAh. Now your cell gets older and degrades to 2000 mAh. You still load your cell to 4.2V and discharge to 3.5V. Like new. But get only 2000 mAh instead of 3000 mAh.

Now tesla limits Vmax to 4.1V. Then you have only about 85% left from your reduced capacity. So 2000 * 0.85 = 1700 mAh.

No. You still mix up capacity and SOC.

100% SOC is always 4.2V. New, after 50'000 miles, after 500'000 miles. Always.

Capacity goes down over time.

You have a usable capacity between about 4.2V and 3.5V. When a cell is new you can use f.e. 3000 mAh. Now your cell gets older and degrades to 2000 mAh. You still load your cell to 4.2V and discharge to 3.5V. Like new. But get only 2000 mAh instead of 3000 mAh.

Now tesla limits Vmax to 4.1V. Then you have only about 85% left from your reduced capacity. So 2000 * 0.85 = 1700 mAh.

Thank you, Gizmo74. So in the iPhone example: State of charge always reads 100% when fully charged; Capacity is the percentage reported in the battery health menu. You are saying that regardless of the capacity (decreasing with age), the maximum voltage on the iPhone battery is always some value "x" when fully charged. Do we know for sure that other device manufacturers don't artificially reduce the max voltage for various reasons (like safety) as the battery ages? A user would never know, and it would be viewed as normal capacity degradation.

 

[⚡️ELECTROMAN⚡️]

Isn’t this how the iPhone BMS works? I charge every night to 100%. The screen shows I’m at 100% when in fact I am only charging to 95% of the original capacity. The 95% number is found in the battery health information. I just replaced my wife’s battery which was charge limited by Apple to 75% and was consequently slowing the phone down (the battery meter still showed 100% after a night’s charge).

Yeah and that's How Tesla's work also. I have software locked 60kWh and it will say 100% charged when it's actually only around 80%.

 

[sorka]

How do we know what that usable capacity is? They are not telling us. And, by not telling, in essence, they are the one who are saying the display is showing the “100%” of the original full capacity.

Actually, we know they haven't. How?

This is how:

So glad I'm still on V8 although I've lost app access since if I'm not driving the car it's network connection is nulled out to my Verizon hotspot without a sim card. I'm hoping that Tesla will not download software WHILE I'm driving so that's the way it will stay until the eliminate server side support for the current VPN cert at which point I'll have to accept the update if I want to keep in vehicle services.

 

[sorka]

It's about a limited number of cars that have suddenly been stripped of a good amount of their range by a software update while most cars are unaffected. It cannot be degradation because it doesn't happen to just a few cars and not suddenly like this.

How do we know most cars aren't effected?

 

[sorka]

Isn’t this how the iPhone BMS works? I charge every night to 100%. The screen shows I’m at 100% when in fact I am only charging to 95% of the original capacity. The 95% number is found in the battery health information. I just replaced my wife’s battery which was charge limited by Apple to 75% and was consequently slowing the phone down (the battery meter still showed 100% after a night’s charge).

Your wrong. Your iphone battery only HAS 95% of the original capacity left. It has degraded 5% and the BMS is charging to the 100% of that remaining capacity. Are you sure you have an EE

 

[sorka]

Thank you, Gizmo74. So in the iPhone example: State of charge always reads 100% when fully charged; Capacity is the percentage reported in the battery health menu. You are saying that regardless of the capacity (decreasing with age), the maximum voltage on the iPhone battery is always some value "x" when fully charged. Do we know for sure that other device manufacturers don't artificially reduce the max voltage for various reasons (like safety) as the battery ages? A user would never know, and it would be viewed as normal capacity degradation.

Yes, there are other example where manufacturers reduced maximum charge in order to prevent fires. The Note 7, for example, received a software update to prevent charging to the top. It was a safety measure put into place to prevent any more exploding Notes until the owners could return them FOR A FULL 100% REFUND!

 

[sorka]

Yeah and that's How Tesla's work also. I have software locked 60kWh and it will say 100% charged when it's actually only around 80%.

And in this example, this is what the contract between the person buying the car and Tesla was and what the person buying the car paid for.

 

[VT_EE]

Your wrong. Your iphone battery only HAS 95% of the original capacity left. It has degraded 5% and the BMS is charging to the 100% of that remaining capacity. Are you sure you have an EE

Umm, that is exactly what I am saying. Perhaps the wording could be better.

As any EE knows, the field is very diverse. I've been designing and troubleshooting communications systems for years, but back in the day I had a few power and electronics classes. Battery classes, not so much.

Without seeing their code or measuring an iPhone battery for voltage at full charge, there is no way of knowing if other manufacturers don't artificially reduce max voltage at full charge as the battery ages. I'd consider it part of the design if done from the get-go. For all we know, the e-Tron might do exactly the same thing except Audi has purposely designed in a ton of unused capacity so they won't have to deal with this type of situation.

 

[BigNick]

Was the battery warm?

The 429 kW run, the car showed Max Battery was Ready. I don’t think Max Battery heats to a full 50C/122F anymore.

When I charged (HPWC, not SC)to 90% the battery was about 90F. I didn’t take a reading as the 99% charge completed.

 

[sorka]

Umm, that is exactly what I am saying. Perhaps the wording could be better.

As any EE knows, the field is very diverse. I've been designing and troubleshooting communications systems for years, but back in the day I had a few power and electronics classes. Battery classes, not so much.

Without seeing their code or measuring an iPhone battery for voltage at full charge, there is no way of knowing if other manufacturers don't artificially reduce max voltage at full charge as the battery ages. I'd consider it part of the design if done from the get-go. For all we know, the e-Tron might do exactly the same thing except Audi has purposely designed in a ton of unused capacity so they won't have to deal with this type of situation.

Between both my wife's and daughters Iphone 6S+'s, I've removed 5 degraded batteries fully charged and they were all just under 4.2 volts. My daughter just got the XR so I won't ever be replacing the battery on that phone. On a 6s it takes about 10 minutes.

 

[sorka]

The 429 kW run, the car showed Max Battery was Ready. I don’t think Max Battery heats to a full 50C/122F anymore.

When I charged (HPWC, not SC)to 90% the battery was about 90F. I didn’t take a reading as the 99% charge completed.

My recent 443K was at 110F at 90%

Tells us how many amps. If Tesla reduces power via sofware it will be by drawing less current which is how you control how much power (current x voltage) to draw from the battery.

 

[Droschke]

Pre-Diag: There are no HV battery faults. The decrease in range is due to the increase in ambient heat. The Battery management system has recalculated the range to compensate for the energy it has to consume to cool the battery and drive unit(s) in hot weather.

So, then nothing to worry about. The cooler weather will arrive soon and the lost capacity will be given back

 

[electronblue]

So, then nothing to worry about. The cooler weather will arrive soon and the lost capacity will be given back

At this rate our Teslas will be appreciating assets by wintertime!

 

[BigNick]

If you're still pulling 1525 amps, then the drop in power is not due to software. So how many amps are you pulling wide open throttle as you pass 40 mph?

Also, battery temp(as long as it's not really cold) and SOC(as long as it's not below 30%) won't make any difference in amps drawn so don't go max battery just to pull that number.

Didn’t think I could pull more than 1500 on a P85DL.

 

[sorka]

Didn’t think I could pull more than 1500 on a P85DL.

It was advertised as a 15000 amps on the L upgrade but I've always pulled 1525 logged from the canbus.

 

[DJRas]

So the last 3 charged it has maintained 23 miles lost. After getting airbags replaced, I had to ask for the notes the person read to me the other day. Service rep copy and pasted it in an e-mail.

Me: Severe battery degradation within last month. Lost mileage every time I’ve charged since I noticed a severe drop in range. So far within last month lost at least 23 miles.

Pre-Diag: There are no HV battery faults. The decrease in range is due to the increase in ambient heat. The Battery management system has recalculated the range to compensate for the energy it has to consume to cool the battery and drive unit(s) in hot weather.

So checking on my TeslaFi log I was already losing range when it wasn't hot yet so that's a bunch of BS. It wasn't until recently it got hot. I even asked the person (not tech) that does that mean I'll start gaining some miles lost when it gets cool again? I already know the answer to that. If this was true, I would have noticed higher than normal degradation the last two summers.

I'm not sure if this is specific to this service center (Rocklin) but they don't even wash cars now because of how overwhelmed they are from new deliveries and those take priority.

I call BS on Tesla explanation.