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Wiki Sudden Loss Of Range With 2019.16.x Software

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Yes its cold (54F)...over the years they have increased the temp threshold for limited regen....another way to protect the battery. I see it at that temperature too but does not take a long time to warm up and get these lines to go away.
Keeping an eye on the energy meter on the IC and TM-Spy, i have found the regen limit disappears once all modules reach 59F/15C.
 
I am doing my part by registering my complaints with the service center.
But my real hope is that when there are enough Tesla's sold that there will be an aftermarket for 3rd party battery manufacturers that would be able to offer better battery upgrades in the future.
I agree that would be nice, although I doubt I would take advantage of it. However in a few years what are these cars going to be worth? With my 2014 I wouldn't be willing to spend $20k for a new battery on a car worth may $20-25k in 3 years with the new battery. I would rather use that money as a down payment on a newer car. These are speculative values and costs but I believe they are close to what they could be. In short I don't think there would be enough of a market for a company to invest in developing and selling these batteries.
 
I'm so tired of this, wish it was late February or March so we could know more of how Tesla will resolve this.
It’s Tesla. They will just deny any problem. I asked my service center if there were no faults detected when charging but I never got more than 20kw is that considered normal they just remained silent.
 
Keeping an eye on the energy meter on the IC and TM-Spy, i have found the regen limit disappears once all modules reach 59F/15C.
Yes the dotted line disappears at a battery temp. of approx. 15C. But at that time my 70D has only a regen of approx 43kW - out of a max. of 87,5kW (Can be seen with ScanMyTesla : "BMS max charge" - and the numbers matches the "Battery power" reading when doing regen). So it takes a bit longer before you reach max regen.
 
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Slightly off tangent perhaps, but related, here’s a question about Tesla’s ethics on their ‘fixed’ range multiplier.


Back in 2016 (new), my MS85D that I was told would have a range of 270 miles (EPA) actually had a ‘typical’ range displayed of 265 miles @ 100% SoC. That is EU ’Typical’, which I understand to be US ‘Rated’.

So if I use the 290 watt/mi multiplier for EU typical range (US Rated) provided from the post by @wk057 , my new (85kWh??) battery at 100% SoC had 76.85kWh of available energy (265 X 0.290).

Just prior to the software capping of my battery from 4.2V to 4.09V in June, I had a displayed typical (US Rated) range of 256 miles at 100% SoC. That would suggest that I had 74.24kWh of useable capacity if I use the 290Wh/mi multiplier.

However having utilised TM Spy I now now see that my actual (post software capped) capacity is 65.7kWh with 234 typical (US Rated) miles of range displayed. If I divide the 65.7kWh by 234 miles though, I now have a more optimistic multiplier of 281Wh.

As I didn’t have the diagnostic equipment/software until post the cap, the question is at what point did Tesla change the multiplier and why?

Between the new battery in 2016 and the pre-software update, if the 290Wh/mi multiplier was constant, then the car would suggest I only lost 2.61kWhs ie from 76.85kWh (useable new) to 74.24kWh just pre-software update, with a further loss of 8.54kWhs instant with the software update.

Obviously the problem here over the past three and a bit years I have been thinking that all my charging, and yes mainly DCFC, hasn’t been too harmful to my battery as I had only lost 2.61kWhs.

However if Tesla have been slowly changing the 290Wh multiplier in the background (as we don’t see it) and moving towards 281kWh in my case (and who is to say they didn’t change it more and moved it back slightly), then I might have actually lost much more in the preceding three years and just never noticed it.

So potentially in June, just prior to the update, if i use the new 281Wh multiplier, I might have only had 71.93kWhs. That’s significantly different to the 74.24kWhs I thought I had. So rather than the relatively small 2.61kWhs deg, I actually had 4.92kWhs of deg over those (pre-software update) three years. Which would then mean the software capped loss is reduced to 6.23kWhs. Still significant, but less.


Or it could be that the 234 miles of range now shown at 65.7kWhs (from TM Spy data), using 281Wh/mi, is actually only the 226 miles I saw immediately after the software update if we use the 290Wh/mi.


Apologies if I’ve just had a convoluted, rambling rant, but I guess that is a long winded way of saying - is it right that Tesla can slowly change the range algorithm in the background, making you think your battery pack is actually doing quite well over time. So a lot more Tesla owners out there might be being affected, but just don’t realise it because their indicated range hasn’t changed?
 
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It’s best not to mix voltage capping and the range multiplier as it confuses the issue.

The fact is that your battery did lose around 10% capacity overnight with the 2019.16.x update.

This is not normal degradation.

It’s also possible that Tesla is monkeying around with the range multiplier to give the illusion that your range is not severely impacted when you look at the range estimate based on SOC.

What I’ve noticed recently is that the range indicator is a pure work of fiction and that the only reasonable range estimate comes from the nav system on a journey.
 
Slightly off tangent perhaps, but related, here’s a question about Tesla’s ethics on their ‘fixed’ range multiplier.


Back in 2016 (new), my MS85D that I was told would have a range of 270 miles (EPA) actually had a ‘typical’ range displayed of 265 miles @ 100% SoC. That is EU ’Typical’, which I understand to be US ‘Rated’.

So if I use the 290 watt/mi multiplier for EU typical range (US Rated) provided from the post by @wk057 , my new (85kWh??) battery at 100% SoC had 76.85kWh of available energy (265 X 0.290).

Just prior to the software capping of my battery from 4.2V to 4.09V in June, I had a displayed typical (US Rated) range of 256 miles at 100% SoC. That would suggest that I had 74.24kWh of useable capacity if I use the 290Wh/mi multiplier.

However having utilised TM Spy I now now see that my actual (post software capped) capacity is 65.7kWh with 234 typical (US Rated) miles of range displayed. If I divide the 65.7kWh by 234 miles though, I now have a more optimistic multiplier of 281Wh.

As I didn’t have the diagnostic equipment/software until post the cap, the question is at what point did Tesla change the multiplier and why?

Between the new battery in 2016 and the pre-software update, if the 290Wh/mi multiplier was constant, then the car would suggest I only lost 2.61kWhs ie from 76.85kWh (useable new) to 74.24kWh just pre-software update, with a further loss of 8.54kWhs instant with the software update.

Obviously the problem here over the past three and a bit years I have been thinking that all my charging, and yes mainly DCFC, hasn’t been too harmful to my battery as I had only lost 2.61kWhs.

However if Tesla have been slowly changing the 290Wh multiplier in the background (as we don’t see it) and moving towards 281kWh in my case (and who is to say they didn’t change it more and moved it back slightly), then I might have actually lost much more in the preceding three years and just never noticed it.

So potentially in June, just prior to the update, if i use the new 281Wh multiplier, I might have only had 71.93kWhs. That’s significantly different to the 74.24kWhs I thought I had. So rather than the relatively small 2.61kWhs deg, I actually had 4.92kWhs of deg over those (pre-software update) three years. Which would then mean the software capped loss is reduced to 6.23kWhs. Still significant, but less.


Or it could be that the 234 miles of range now shown at 65.7kWhs (from TM Spy data), using 281Wh/mi, is actually only the 226 miles I saw immediately after the software update if we use the 290Wh/mi.


Apologies if I’ve just had a convoluted, rambling rant, but I guess that is a long winded way of saying - is it right that Tesla can slowly change the range algorithm in the background, making you think your battery pack is actually doing quite well over time. So a lot more Tesla owners out there might be being affected, but just don’t realise it because their indicated range hasn’t changed?

Is there any evidence of this? The 295wh/mi was already conservative. 281Wh/mi is impossible on the single motor vehicles unless you’re going under 60mph
 
Is there any evidence of this? The 295wh/mi was already conservative. 281Wh/mi is impossible on the single motor vehicles unless you’re going under 60mph

I’m just taking the 290 wh/mi the figure provided by @wk057 for the 85D in his early diagnostics of the Tesla pack/software - apparently taken from the Tesla firmware.

I have a dual motor (85D) and whilst this isn’t a scientific bit of evidence, I used to average around 290-300 watt per mile on long distance journeys and would easily manage those ranges.

Obviously can’t any more.

Precisely my point on the 281 wh/mi - this is simply the figure I get from the CAN Bus data provided by TM Spy which shows that I have 234 miles of range based on a 65.7 available kWh capacity.
 
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Ran across a couple papers that discuss li-ion failure modes that could be relevant here and methods to mitigate which Tesla appears to be utilizing based on descriptions of vehicle behavior during charging:

https://www.cell.com/joule/fulltext/S2542-4351(19)30481-7
Whiskers, surface growth and dendrites in lithium batteries | The Source | Washington University in St. Louis

The short of it is that by heating batteries to high temperatures during charging (60C, for example), this lets you charge at rapid rates without contributing to lithium plating and associated dendrite growth - the type of dendrite growth that can result in catastrophic cell failure.

On the reverse side, you must also then cool off the battery when done charging at a rapid rate to reduce the rate of SEI growth that occurs fastest at elevated temperatures.

Sound familiar?

This sounds a lot like the behavior that Tesla has implemented:
1. Preheating batteries when navigating to to Superchargers.
2. Hyperactive cooling system if the battery is hot, at high SOC when charging rate is already slowed and cooling the batteries further even when cooling is done.
3. Limit maximum cell voltage and limit charge rates - this also reduces rate of dendrite growth.

Another interesting presentation on lithium-ion lithium plating and dendrite growth from NASA and how to detect lithium plating:
https://www.nasa.gov/sites/default/files/atoms/files/1-lithium_plating_azimmerman.pdf