Decreasing rated range.

[WarpedOne]

Where someone after few months of driving talks about 1% range degradation? Nothing real about that.
I really really wish I could quote that post ...

 

[AmpedRealtor]

I've been called out on my statement that:


I was writting on memory, here are my original sources:
First: i got told from a tesla sales rep that 3% per year is an acceptable loss. according to excel that is 78.37% of original capacity at year 8.
Second and the main one - I cannot find that post any more It was here on TMC from a guy that specificaly asked tesla rep what if his capacity drops to 70% before age of 8 years and he got the word "replacement".

Dancing on "the warranty does not state anything regarding range" is giving tesla excuse to not cover excessive range loss if it should happen.
We are better off if we expect them to replace the battery as they will feel the comunity pressure. Giving up in advance doesn't serve us any good.

It's nice to think about Tesla being altruistic and giving us things they never promised or said they would, but that's not the reality. While I would like to think that you are correct, the battery pack costs over $45,000 to replace. I don't think Tesla is going to be in a very kumbaya mood when you ask them for a $45,000 part because your battery capacity dropped 30%. It just isn't going to happen.

As you can tell from my screen name, I work in real estate. Half of my job is ensuring contract compliance. If it's not in writing, forget it.

 

[ecarfan]

I was writting on memory, here are my original sources:
First: i got told from a tesla sales rep that 3% per year is an acceptable loss. according to excel that is 78.37% of original capacity at year 8.
Second and the main one - I cannot find that post any more It was here on TMC from a guy that specificaly asked tesla rep what if his capacity drops to 70% before age of 8 years and he got the word "replacement".

What a Tesla "sales rep" says about the battery warranty means nothing to me. What matters is the words in the written warranty AND how Tesla interprets those words (all words are subject to interpretation) and in some cases how a court of law interprets those words (hoping it never comes to that).

Everyone should know that the battery capacity will decrease over time. How much it will decrease, and how much is enough to trigger a battery replacement under warranty will of course be a matter of dispute.

 

[rlang59]

I've been called out on my statement that:


I was writting on memory, here are my original sources:
First: i got told from a tesla sales rep that 3% per year is an acceptable loss. according to excel that is 78.37% of original capacity at year 8.
Second and the main one - I cannot find that post any more It was here on TMC from a guy that specificaly asked tesla rep what if his capacity drops to 70% before age of 8 years and he got the word "replacement".

Dancing on "the warranty does not state anything regarding range" is giving tesla excuse to not cover excessive range loss if it should happen.
We are better off if we expect them to replace the battery as they will feel the comunity pressure. Giving up in advance doesn't serve us any good.

It's not dancing on anything, the warranty specifically states that degradation is not covered so don't get your hopes up.

 

[jerry33]

I've read every post in this thread, and there's something that still doesn't add up. The reported rated miles at 90%/100% seem to fall into two camps: A lot of 85 owners are reporting around 240 to 245 rated miles when they charge to 100%. But a lot of owners--especially those that have very high mileage--are reporting they still have 260-265 rated miles at 100%. Similarly, at 90%, a lot of owners are around 210-215 rated miles, and a lot of others are around 225-235.

In general cars do better with a lot of miles in a short period than a few miles over a long period. I don't expect EVs to be an exception to this.

I don't worry about 90% at all, and 100% is 259-260 (5.8, haven't done 100% of 5.9 yet). Seems about right for a year and 20K miles.

 

[apacheguy]

I don't worry about 90% at all, and 100% is 259-260 (5.8, haven't done 100% of 5.9 yet). Seems about right for a year and 20K miles.

Agree, that does seem about right for a car with those numbers. But many of us with similar stats are only getting 240-245 on 100%, which seems rather low. Haven't done 100% on 5.9 yet.

I've read every post in this thread, and there's something that still doesn't add up. The reported rated miles at 90%/100% seem to fall into two camps: A lot of 85 owners are reporting around 240 to 245 rated miles when they charge to 100%. But a lot of owners--especially those that have very high mileage--are reporting they still have 260-265 rated miles at 100%. Similarly, at 90%, a lot of owners are around 210-215 rated miles, and a lot of others are around 225-235.

Ok, so you think that the lower W/mi owners show higher rated miles at 100%, correct? My lifetime W/mi = 333. Pretty low I think especially considering those that live in colder climates have substantially higher W/mi and get far more rated miles than me at 100%.

 

[Stoneymonster]

I am at 250 miles for a 100% charge on 5.9 with 15k miles, 16 months. This is maybe its fifth or sixth range charge. I usually charge to 80%.

 

[walla2]

Actually your perceived degradation is only 2.6%, not 4%. 258 miles out of 265 miles is 97.4%, or 2.6% loss.

Sorry I was averaging my 5.8 100% numbers with my 5.9 100% number but didn't make that clear. My loss is between 2.6 to 6.5% at 6K miles depending on which firmware you believe if you believe the numbers to be accurate at all. At 80,000 miles at the higher rate of loss, I will have a Signature paperweight on my hands. Obviously, I hope the numbers become more realistic over time and slow down.

 

[WarpedOne]

My loss is between 2.6 to 6.5% at 6K miles depending on which firmware you believe if you believe the numbers to be accurate at all

Those are the most important words of all.
walla2, I see you still have the Roadster. How is its battery doing? Degrading slower than your MS?

 

[Kraken]

Just because the algorithm fix hasn't seem to change the 100%, doesn't mean here still aren't other issues with the algorithm that haven't been fixed. I think it is more likely that there is another issue with the algorithm than it is that were seeing much degradation. I say this because those who've used the battery the most are seeing the least change.... Where as with degradation you would expect the opposite.

It's still quite possible that charging to less than 100 makes the car struggle to calculate the full capability of the car, and the recent algorithm only helped calibrate charges of less than 100%.

Anyway these are all just estimates that tend to vary wildly from actual performance due to a lot of factors like driving style, weather, terrain, and road conditions. A mile is almost never a mile.

 

[WarpedOne]

There is only one "reliable" way of measuring degradation - repeat the EPA cycle range measurement.
Everything else is judging the army size buy dust it raised.

What can Range-Estimation-Alghoritym know?
1. It can measure battery voltage at different power output/input (Current Out, Current In) - voltage sag
2. It can measure battery voltage when car is off and main battery is disconnected i.e. no current out - floating voltage
3. It can measure how much Wh went into the battery and how much Wh already came out - Wh accounting
4. It can measure how many miles where driven over those WhIn - WhOut - feet accounting
5. It can measure how "fast" battery voltage rises when charging - V/Wh ration
6. it can measure how "fast" battery voltage decreases when discharging - voltage sag is dilluting the correct result
7. It can measure how fast battery voltage changes with changes in power output - speed of voltage rise after decresing power output

Also keep in mind that voltage difference between completely full and empty battery is only about 20% of max voltage - voltage sag can be twice as large.
Add temperature effects on component resistance and its effect on battery voltage and resistance. Cold battery will have higher resistance hence. Battery at 10 degrees behaves differently as when at 20 degrees and different when at 30 etc.
All these things form a big complex pile of inter-dependant factors that all act on their own but are also dependant on others.
They can tell if battery is very good, good, poor or very poor. They cannot differentiate between "95%" and "96%" worn battery.

The most sure way of telling the end result is statistics - measure many different packs and then repeat the EPA range dance to determine how set of xx values translates into one single number precise to 0,3%.
All above measurements and results are also more precise with heavier deep-cycling therefore people who drive long distance have their REA perform better - less "calculation artifact accumulation". People who seldomly drive SOC from 100 close to 0 don't have that privilege. REA must live with what it has - differences of measurements at say 80% and 75% SOC.

And also don't forget that REA must by design err on the safe side - it must collect errors on 'degradation' side. It would be stupid and dangerous if it allowed for errors to show "improvement" i.e. higher range than new.

All these add into one simple fact: without doing a test in controled and repeatable conditions i.e. EPA test one cannot talk about battery degradation but only about Range-Estimation degradation.

 

[bluetinc]

For everyone here that is still on 5.8, or has their full charge numbers from 5.8 using the "ideal" setting. My cars data shows that my "ideal" miles at 100% has not changed at all. I am looking for others to either confirm this, or offer contradicting data as I am only a data set of 1

(reference my full data in post 1207 Decreasing rated range. - Page 121)

Peter

 

[SFOTurtle]

Just reporting numbers here and not ascribing to degradation or balancing: 60 battery, 17,200 miles, 5.9, 100% SOC yielded 196.7 rated in 70 degree weather with standard/non-range mode settting. Forgot to record the ideal miles. I have consistently been seeing 177 at 90% SOC since 5.9 was installed.

 

[Rainbow]

So if the average daily commute is 100 miles or more, it is beyond the recommended battery use and may result in short battery life?

Best charging strategy for battery life?? Alert says (paraphrase). | Forums | Tesla Motors

 

[Doug_G]

Since the 5.9 update my car has "gained" range. I just did a full range charge and got 410 km (256 mi) Rated. That's a 3% drop from brand-new. Car is coming up on 28,000 km (17,500 mi).

 

[VolkerP]

I'd roughen that to 1% per 10.000km. Nice!

 

[Doug_G]

Indeed, it's doing better than the Roadster.

This chemistry reportedly drops a bit at first then settles down. It will be interesting to see if that pans out.

 

[strengthcoach4]

Firmware 5.9 100% SOC 199 Rated and 227 Ideal. 27,700 miles on car

 

[yobigd20]

I've read every post in this thread, and there's something that still doesn't add up. The reported rated miles at 90%/100% seem to fall into two camps: A lot of 85 owners are reporting around 240 to 245 rated miles when they charge to 100%. But a lot of owners--especially those that have very high mileage--are reporting they still have 260-265 rated miles at 100%. Similarly, at 90%, a lot of owners are around 210-215 rated miles, and a lot of others are around 225-235.

it's actually very simple. those of us that use more of our battery packs on a daily basis (the highest mileage drivers) have more accurate battery capacity estimation numbers. To "guess" at battery capacity is actually a very complex process (it's not like a digital scale with highly accurate results). the calculation is algorithmic with a very small error deviation. To the drivers that aren't fully using the pack frequently (< 10% and >90%), that deviation grows and grows while those of us frequency going below 10% and above 90% simply have a more accurate usable capacity estimation. neither usage pattern accurately reflects actual battery degradation. So who really knows if someone with 5k miles has more capacity than someone with 50k miles. The actual battery capacity data they use in their algorithms is intentionally hidden from all of us.

- - - Updated - - -

Firmware 5.9 100% SOC 199 Rated and 227 Ideal. 27,700 miles on car

is that a 60 or 85?

 

[bluetinc]

Doug, On my car, the "rated mile" energy unit was reduced by about 2%, which has the effect of showing more miles when fully charged but is essentially an illusion, especially if comparing 5.9 numbers vs. old numbers. Do you happen to have ideal numbers for when the car was new, and now?

Peter

Since the 5.9 update my car has "gained" range. I just did a full range charge and got 410 km (256 mi) Rated. That's a 3% drop from brand-new. Car is coming up on 28,000 km (17,500 mi).