Everyone has different theories. And everyone cites different studies. Just because the US Army says it's so doesn't mean it's so. There are plenty of other battery researchers at reputable institutions that suggest 3.92 V per cell is ideal (NASA among them, ask jpet). My rule of thumb is below 4 V per cell so I only charge to 80%.
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Everyone has different theories. And everyone cites different studies. Just because the US Army says it's so doesn't mean it's so. There are plenty of other battery researchers at reputable institutions that suggest 3.92 V per cell is ideal (NASA among them, ask jpet). My rule of thumb is below 4 V per cell so I only charge to 80%.
chriSharek
Member
I notice that this thread began in October. Could forecasting of range take into account the weather, which would reduce range as well as the normal battery degradation in the first year?
If you browse through the thread you'll see In most cases with the 90D it was not a weather/temp issue. The thread started in October because at the time a couple dozen of us that bought new cars a month earlier were noticing it was dropping rated range at the rate of one mile per week. For about half of those people the temperatures stayed between 80-90 degrees through the entire time. Most of us ended up with between 8 to 12 less displayed rated miles than what we started with. Tesla says there is no actual range loss and that it's a software issue that will be fixed.
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Much simpler and safer to leave the garage door open with the heat cranked on full to drain the battery. Might take longer and be less fun than driving, but you're guaranteed to be parked in range of a reliable charge point when drained.
I've been only charging to 80% lately, so I have not been monitoring the 90% rated range recently.
However, I did charge to 90% this week and the good news is it has not declined since early January. It's now hovering at 243-244. Not great for a 90D with 6k miles on it, but at least it has stopped dropping 1 mile of range every week as it was last year. I really hope the firmware fix sort this out.
However, I did charge to 90% this week and the good news is it has not declined since early January. It's now hovering at 243-244. Not great for a 90D with 6k miles on it, but at least it has stopped dropping 1 mile of range every week as it was last year. I really hope the firmware fix sort this out.
This sounds a lot like the P85D discussions about horsepower and the P90D discussions about 1/4 mile. And if you really want to roll back the clock: the Sig premium on Model S.
Tesla is, unfortunately, building a reputation among owners of providing questionable value for additional premium feature offerings. It saddens me.
I take it you doubt them but it's been just one update not "several" since they told me that.
Since I think around the 7.1 update, I've found the car at various levels of charge after it completes charging to 90%. I've caught it as much as 5% loss in a day (morning to night) while still plugged in.
It seems like it's the HVAC since every time I've noticed the range discrepancy. The car is comfortable or even noticeable warmer than the garage. Though Tesla Log is not showing the fan being enabled at all, so I'm at a loss how the Tesla cabin can be 70F in a ~50F garage even after 12h.
I don't have smart preconditioning enabled. Even so, I thought the HVAC is supposed to run off shore power.
According to Tesla Log, it seems I've lost 0mi at 90% since Dec., recorded 251.3mi this morning. So that's a plus I suppose. Just annoying that the depending on how long from reaching 90% and departure, the CID will show 242-248mi of range. It seems to always lose the first 1% roughly an hour after charge completion and the rest at various rates, if at all.
It seems like it's the HVAC since every time I've noticed the range discrepancy. The car is comfortable or even noticeable warmer than the garage. Though Tesla Log is not showing the fan being enabled at all, so I'm at a loss how the Tesla cabin can be 70F in a ~50F garage even after 12h.
I don't have smart preconditioning enabled. Even so, I thought the HVAC is supposed to run off shore power.
According to Tesla Log, it seems I've lost 0mi at 90% since Dec., recorded 251.3mi this morning. So that's a plus I suppose. Just annoying that the depending on how long from reaching 90% and departure, the CID will show 242-248mi of range. It seems to always lose the first 1% roughly an hour after charge completion and the rest at various rates, if at all.
And how are you going to measure that since the kw meter won't register anything while stopped?
You could use the heater to take the battery all the way down to zero the first time. Then charge to 100%, let it complete, then drive it around until it reaches the dead point, at which point you take your Wh/mi * your miles and compare that to rated Wh/mi * rated miles to see how close you are to the full capacity
I brought my car in for service today and I mentioned the range loss: (90% charge/range mode off, delivered 9/30/15) from approx. 265 to currently 242 (with some flux). The SM stated it was a function of the algorithm estimating range based on driving conditions including how I drive. They assured me that the battery was in perfect health and stated future firmware updates will continue to improve the algorithm. I do believe, that the range estimate probably over estimates my range based on the cold winter driving and has nothing to do with battery life/health. “Range decline” seems like it is just the algorithm adapting to the driving, not the battery capacity.
Well, had you bought an 85D instead of the 90D your displayed rated range would be about the same as you have now but you would have saved $3,000. Many of us got a somewhat different story from the Service Center than what you got. Mainly that it is an algorithm issue with the 90D but had nothing to do with driving conditions.
BertL
Active Member
7.1 2.12.126 - No early result improvement
Installed firmware 7.1 2.12.126 yesterday on my S90D, which some other owners have reported contains changes to BMS (as many recent releases have). Findings are too early to draw any final conclusions except that I see no immediate benefit from the latest firmware with displayed Rated Range. Rated Range showed 248 miles before and after the update. This morning, my overnight 90% charge is showing 251 rated range, which is within the 249-251 I've been seeing the last few weeks with both higher and lower temps. I'll be doing a mini road trip next week, and if any new revelations become apparent, I'll post here. For those that care about detail, my current log: View attachment Rated Range.pdf
I still do not believe my S90D rated range drop since delivery correlates significantly to temperature as others have seen with seasonal S85s they own, nor do I have any plans to take my battery down to as close-to-zero charge for back-to-back cycles as some suggest is necessary to understand more.
Installed firmware 7.1 2.12.126 yesterday on my S90D, which some other owners have reported contains changes to BMS (as many recent releases have). Findings are too early to draw any final conclusions except that I see no immediate benefit from the latest firmware with displayed Rated Range. Rated Range showed 248 miles before and after the update. This morning, my overnight 90% charge is showing 251 rated range, which is within the 249-251 I've been seeing the last few weeks with both higher and lower temps. I'll be doing a mini road trip next week, and if any new revelations become apparent, I'll post here. For those that care about detail, my current log: View attachment Rated Range.pdf
I still do not believe my S90D rated range drop since delivery correlates significantly to temperature as others have seen with seasonal S85s they own, nor do I have any plans to take my battery down to as close-to-zero charge for back-to-back cycles as some suggest is necessary to understand more.
I'm thinking the problem might be related to a quality problem with some batteries. Most people don't post when all is good.
We will have a lot more data in the coming months since the 85 option has been eliminated.
We will have a lot more data in the coming months since the 85 option has been eliminated.
MarcG
Active Member
Bert, from looking at your data it seems that you only lost 4 to 6 miles of rated range from your 90% charge levels in about 5 months, is that correct?
If so, I believe this is absolutely expected and there doesn't seem much to be worried about at this point.
If so, I believe this is absolutely expected and there doesn't seem much to be worried about at this point.
BertL
Active Member
Thx, and yes, you're correct in your observation -- although this started back before the decline sorta seems to have leveled-off for the time being. I and a couple others reporting here seem to be some of the first to have received the 90kWh batteries with September 2015 builds. I get the technical explanations folks have suggested or hypothesized, comparisons to the much older 85kWh batteries that may or may not apply to this tech, and also appreciate Rated Range is a sort of estimate -- not an absolute indicating actual range I may or may not achieve with my MS.
As stated earlier, I'm also trying to give Tesla some time to fix their firmware as they confirmed this is not a physical issue with my MS back in December, but a firmware bug that needs resolving. Until that is done though, I have a problem and will continue questioning in the back of my head if I have some sort of earlier degradation that the 90kWh technology or early builds involve. It's also why I try to pay attention with every firmware release - hoping a fix may have been included that isn't listed in the very-high level release notes.
My concerns remain:
- There is nothing in Tesla documentation that says I should expect a rated range decline like I have encountered -- or how much and how quickly. Tesla does not set an expectation with their owners, especially ones that we'll hopefully have more of in the future that are not so techie or forgiving early enthusiasts, who just want to know they are receiving what they paid for.
- I paid $3K for effectively 16 miles of rated range as a "range upgrade" compared to a 85kWh model where more than 40% of both evaporated into thin air within a couple months after delivery using Tesla's own measurement used to describe the benefit of the option: Rated Range. From that POV using Tesla's marketing material for the option I purchased, and the Rated Range I recorded from my IC the day of delivery, Tesla has not provided what was promised and what I paid for ...but as I said, I'm trying to be somewhat reasonable.
- I've had multiple situations where the displayed rated range values are questionable at best going up and down by more than 1 mile within seconds of one-another while I'm parked (ruling out a simple rounding error), and the value I see after charging to 90% is inconsistent from day-to-day by a couple of miles (without being able to establish a temperature correlation), putting more question into what the displayed Rated Range value can really be used for, or how valid it is to begin with
- It appears Range Mode (I have purposely kept mine ON) may also be keeping my displayed Rated Range numbers higher than other S90D who keep that option OFF. IDK that for a fact though because Tesla does not discuss it. (msnow is an example here on TMC where he took delivery just before I did with his S90D and keeps Range Mode OFF, seeing greater rated range degradation than I do, and no significant temperature correlation.)
Tesla needs to do a better job officially explaining what's going on and what to expect in this regard. Assuming Rated Range is just an estimate, they also need to change their firmware to do a better job presenting perhaps an averaged number over some amount of time so the values don't appear to change for no reason. As I said, I'm trying to be a reasonable Owner, but now that Tesla is using the 90kWh battery as the standard in MX and for most MS, they MUST fix their firmware (assuming that is all that needs to be changed) to eliminate questions from future owners, and reduce the number of calls going to Tech Support and time it is taking at SCs dealing with these customer questions, to instill confidence and improve Owner satisfaction so even enthusiasts like myself remove the nagging question if we have been sold a bill of goods or may have some underlying problem no one will yet confirm.
I'm already looking forward to the next firmware release.
Mine is a month older (9/15/2015) and I went from 258 to 247. Or, put another way 11 of the 16 miles that were supposed to be added by buying the 90D vs. the 85D. Hopefully Tesla will fix the algorithm issue soon.
MarcG
Active Member
Guys, don't forget that all models have decreasing rated range - albeit at different rates from the sounds of it.
So even though you may have lost X miles of the 16 you're meant to get over the 85kWh version of your models, the 85kWh packs are losing Y miles over time as well.
The question remains whether the drop for 90kWh is more accentuated, and whether it's true degradatiin or firmware-related -- the latter of which can easily be fixed.
So even though you may have lost X miles of the 16 you're meant to get over the 85kWh version of your models, the 85kWh packs are losing Y miles over time as well.
The question remains whether the drop for 90kWh is more accentuated, and whether it's true degradatiin or firmware-related -- the latter of which can easily be fixed.
Agree. Tesla says it's a lot more than it should be but that it's not "real" degradation but rather a software algorithm issue. Not sure how easy it is to fix but that's their story. I've lost a lot but there are people on this thread that have lost more than the 16 miles or 6-8% total in about 3-4 months.
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