I'm not sure what you mean here. If you mean that some number of cells remain uncharged, then that just won't fly because it would destroy the unused cells to let them discharge fully. Further, if only some of the cells were charged, then we would see top-end ramp down on the Model S 60 that we see on other Teslas, drawing almost nothing at the end.
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I'm not sure what you mean here. If you mean that some number of cells remain uncharged, then that just won't fly because it would destroy the unused cells to let them discharge fully. Further, if only some of the cells were charged, then we would see top-end ramp down on the Model S 60 that we see on other Teslas, drawing almost nothing at the end.
I think he is saying that they don't have to put the unused charge level at the top or bottom, i.e. 0-80% or 20-100%, they could split the difference and a 60 could be using a charge range of 10-90% of the actual 75kWh pack. (Or any other range that consists of 80%.)
But that would be the case on a top limited S60. The rate is pretty much slowing from from 30 something % on up.
It wouldn't make sense for Tesla bottom limit it when they could prevent degradation by limiting it to 85%. The only reason for them to bottom limit it would be so they could activate that capacity from the road if you ran out and were stranded. Would save them sending a tow but you'd still have to pay for the tow anyways, so it's not saving them anything.
The other possible reason for bottom limiting is that if you can't occasionally charge to at least 93%, the balancers won't kick in.
That said, it would be reasonable for them to have a sliding window that sometimes moves around but keeps mostly top limited.
Maximapolak
Member
Easiest way to find out is to have someone charge their MS60 to 100% and then upgrade the battery right there and see at what % the battery will be.
Has anyone ran their MS60 to 0% and try driving farther to see how far it can go?
Has anyone ran their MS60 to 0% and try driving farther to see how far it can go?
DB 2
Member
All cells are treated the same. Locked out is shorthand for that portion of the entire battery's SoC that the 60's software does not allow us to access. For example, external charging (but not regen charging) stops when the entire battery's SoC reaches 89.5% (according to my prediction). How the software treats running out of charge is more complicated and still very much unknown. More details to come.
I wouldn't believe that for a second. It isn't possible given the way the pack is designed/wired.
DB 2
Member
Not the first time a lower level Tesla employee has said something ridiculous.
DB 2
Member
More details:
How did I come up with 89.5% SoC (on the unlocked scale) as the charging limit for the 60?
First, some continue to refer to the 60 as having 80% of the capacity of the 75. This ignores that Tesla uses 60, 70, 75, 85, 90, etc. as designations rather than accurate quantifications of capacity. I believe a more accurate way to compare capacities between the 60 and the 75 (since they have identical hardware, weight, and battery packs) is by EPA rated range. (210 vs. 249 and 218 vs. 259) These two ratios are virtually identical, and imply that the 60 is allowed to use 84.25% of what the 75 can use. Therefore, the 60 is locked out of 15.75% of the actual usable capacity of the battery. If the locked out portion is distributed 1/3 on the bottom and 2/3 on the top, then the 0% level in the 60 is where the 5.25% level is in the 75, and 100% in the 60 is at 89.5% unlocked SoC. BTW, I don't actually claim the level of precision implied by computing to hundredths of a percent, that's just the way the math comes out. Also, all of these SoC figures are as reported by the UI, not the presumably more accurate ones only obtainable with TM-Spy, CAN readers, and the like. Someday, I may try to get one of those, but for now I'm trying to see how far we can get with *publicly available* information. Still more to come.
How did I come up with 89.5% SoC (on the unlocked scale) as the charging limit for the 60?
First, some continue to refer to the 60 as having 80% of the capacity of the 75. This ignores that Tesla uses 60, 70, 75, 85, 90, etc. as designations rather than accurate quantifications of capacity. I believe a more accurate way to compare capacities between the 60 and the 75 (since they have identical hardware, weight, and battery packs) is by EPA rated range. (210 vs. 249 and 218 vs. 259) These two ratios are virtually identical, and imply that the 60 is allowed to use 84.25% of what the 75 can use. Therefore, the 60 is locked out of 15.75% of the actual usable capacity of the battery. If the locked out portion is distributed 1/3 on the bottom and 2/3 on the top, then the 0% level in the 60 is where the 5.25% level is in the 75, and 100% in the 60 is at 89.5% unlocked SoC. BTW, I don't actually claim the level of precision implied by computing to hundredths of a percent, that's just the way the math comes out. Also, all of these SoC figures are as reported by the UI, not the presumably more accurate ones only obtainable with TM-Spy, CAN readers, and the like. Someday, I may try to get one of those, but for now I'm trying to see how far we can get with *publicly available* information. Still more to come.
Bjorn has a video that shows charge rate for the 60:
If that data can be fitted to the curve for a 75 then it would answer the question. We don't have the curve for the 75 though. Tesla has a charge rate curve on the Supercharger page but it's generic and not sufficiently detailed.
DB 2
Member
Thanks. I'm working on plotting the data in this video on top of the data in a similar video of my car supercharging from 5 to 100%. Unfortunately, I can see already that they don't match up as well as I was hoping. Maybe Europe vs. USA or Norway in November vs. So. California in August? Still don't have 75 data to compare to.
Jlwine
Member
I've had a 60D since late July, had originally ordered a 70D but the 60D came out during my one week grace period and i changed. My experience continues to be as i first reported: I charge to 100% ever time I charge.
1. No reduction in Regen when charged to 100%
2. Get nag screen every few days.
3. No significant slow down in charging as it nears 100% at a SC.
1. No reduction in Regen when charged to 100%
2. Get nag screen every few days.
3. No significant slow down in charging as it nears 100% at a SC.
DB 2
Member
Here's the taper curve plot from Bjorn's video, along with one from my car done 5% to 100% with a temperature of 73°F. I'm surprised how much lower his charge rate was at the end than mine.
Some people describe the 60 as having little or no slowdown in charging even near 100%. That is clearly not true. The slowdown is much less pronounced than an unlocked battery, but the charging rate near 100% is still barely more than one-third of that at the peak even in the 60.
Some people describe the 60 as having little or no slowdown in charging even near 100%. That is clearly not true. The slowdown is much less pronounced than an unlocked battery, but the charging rate near 100% is still barely more than one-third of that at the peak even in the 60.
Hi DB2, how does your calculation change below now that it has come out that the 62 is actually 62.5kWh and 75 is 72.6kWh ..
Tesla Motors: PLEASE stop lying about specifications (60 to 75 upgrade)
Took delivery of my S60 last month and trying to figure what is safe level to charge to..
thanks..
Tesla Motors: PLEASE stop lying about specifications (60 to 75 upgrade)
Took delivery of my S60 last month and trying to figure what is safe level to charge to..
thanks..
My thoughts exactly! with all this bickering back and forth, why in the hell doesn't someone with a new 60 get TM-Spy (or have a fellow TMC owner help out) and drain it from 0 to 100% and watch the cell voltages..
Easy peasy and done fricken deal. Enough with this bickering!
Just look at the cell voltages already!
TonyWilliams
Active Member
What voltage does a 60D show at 100% ? That's your answer. Not rocket science.
The configuration is 84 cells in series for all 60-70-75 batteries. Max voltage is 354v at 4.2v per cell.
If the car is charging up to some voltage below 354v at 100%, then you have your answer.
DB 2
Member
It certainly shoots down my assumption that the split was 1/3 - 2/3. That was always just a guess. It's tough to find a pattern when you only have one data point. I'll explain below for anyone interested, but to answer your question, my current assumption/guess is that the 15.75% locked out is split 1.75% on the bottom and 14% on the top. The photo @wk057 posted is about as definitive as one could hope for, barring you finding someone with $9K burning a hole in their pocket and wanting to turn a great deal (relatively speaking) into just a very good car.
FWIW, I'm still convinced that 15.75% (approximately) is the correct total lockout (with a caveat that I'm still working on and will post when I'm a little more confident.) No other percentage is consistent with the EPA rated ranges, and those are calculated using a very specific formula/method.
There is evidence for the idea of having the forbidden fruit at both ends of the tree. It is the *one data point* from earlier, and you will find it here. Extrapolating to 100% SOC, he went from 355.6 km to 384.4 km typical. He gained 28.8 km, 10 of which were on the bottom. I saw that this was within a rounding error of 1/3 bottom, 2/3 top, realizing that there are plenty of other reasonable interpretations and no guarantee that the 60's even followed the pattern set by the 70's, not to mention USA vs. Europe.
Another obvious reasonable interpretation that actually fits the new data (with a stretch) is that the 10 km typical does not represent 1/3 of the lockout, but simply 10 km. This would allow someone paying the fee to see an immediate response while Tesla keeps maximum control (*hint*) over the vast majority of the lockout of those who don't pay.
For the 60D to 75D scenario, 1.75% of 259 rated miles is 4.5 miles. Compare with his result of 6 miles typical and you get (barely) within range of consistency. It's even closer if his typical is our ideal and is significantly inflated compared to rated.
Some updates on this. Here is a supercharging curve for my 75D from 8% to 92%. Also, based on Bjorn's video, the 100% of 60 is around 92% of 75D based on supercharging rates (the Tesla 60D stops at a supercharging rate of 28 Kwh, which is equivalent to when my car's SOC is around 92%). However, if we were to go by DB 2's data, then it suggests that the 60 100% is at around 86% of the 75 battery. I think we need some more 60D owner's to chime in on what charging rate they get at 100%.
SageBrush
REJECT Fascism
Thinking out loud here, with a good measure of ignorance added in:
I understand the idea of measuring the battery voltage at full charge to clarify this question of where the buffer sits, but
why not just compare the SOCs of locked and unlocked batteries where the charge rate rapidly tapers ? Seems like it should be good for a qualitative answer, which is I think all we need as a practical matter to be confident that routine 100% charging is safe for battery longevity.
Ambient temperatures probably change the taper point, but a decent data point size should sort that out.
I understand the idea of measuring the battery voltage at full charge to clarify this question of where the buffer sits, but
why not just compare the SOCs of locked and unlocked batteries where the charge rate rapidly tapers ? Seems like it should be good for a qualitative answer, which is I think all we need as a practical matter to be confident that routine 100% charging is safe for battery longevity.
Ambient temperatures probably change the taper point, but a decent data point size should sort that out.
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