90D Range slowly declining

[JonathanD]

Not sure if this has already been covered, but I asked about max battery range and Tesla service explained that the rated range displayed is dependent upon the data from the car. It can understimate if you only occasionally do a max charge.

My S60 went from 209 max to 189 max in 1 year on a full charge. Naturally I brought it up at my appointment. Service performed a full battery diagnostic and said the battery is fine, but if I do some more frequent 100% charges (about once a week) it will give the computer more data to base the rated range on, and it will probably increase.

Hasn't been enough time to report if that advice has worked, but giving it a shot.

 

[BertL]

I'm only 43 days into this game with my S90D, and have really not seen substantive changes with a 90% rated range high at 255 and low of 253; with only one time charging to 100% achieving 282 a couple days ago. Temps have started to drop, but remain moderate compared to many, so I can't see any correlation to my rated range at this point. We only get a few days a year with a real freeze for a few hours in the early mornings where I live here in SoCal. IMHO, I have no alarming or supportive conclusions to draw from my limited data thus far.

Key thing I have proven at least to myself, is the whole rated range display is truly an ongoing estimate (that likely only Tesla knows how and what the parameters are in it's calculation). As I noted back a number of posts, at least once I've caught rated range changing +/-2 miles over less than 60 seconds via my Tesla App while the MS was sitting, off, in my garage mid-day, plugged into its HPWC but not charging ...that still has me baffled why the number would go down, then back up more than just 1 mile if what was occurring was only a rounding difference, and why Tesla would be recalculating it almost in real time -- just another engineering mystery for some of us to ponder.

Anyway, I'm continuing to maintain my log in case a future trend becomes more apparent, or a big seemingly permanent drop-off occurs as others are concerned with. Here's what my data looks like for those interested in the detail: View attachment Rated Range.pdf

 

[apacheguy]

I log range over time and I have never observed the range algo shuffling around in real time. Mine is fairly precise meaning that it charges to roughly the same rated range on any given day and it does not fluctuate throughout the day even if parked and not driven. Of course, it does decline when the car wakes to maintain the 12 V.

On a couple occasions with previous fw and another battery, I did observe rated range increase 1 mile while it was parked and not charging. Outside of those few isolated incidences I've never observed behavior remotely similar to that reported by Bert.

On the extreme end of things, yes, but that's independent from what I'm seeing. The snowflake is when the car "reserves" some range - and I've only seen it twice, for 1-2 miles. This appears to be range calculation sensitivity based on the pack temps.


I went through some of my data from charging last year, as well. Here are some sample 90% charge numbers on days from late 2014 to today, in the middle of each month. I pulled the maximum 90% charge over a span of 2-3 days. I don't have time to correlate the temperature over those days (or look at software updates, or looked at in proximity to the last range charge for rebalancing), but you can see how the number varies seasonally. Note that the peak occurs in the spring, around Mar-Apr. This is the range data reported by the car via the API.


EDIT: I pulled some more data back to January, 2014 and here's what it looks like... keep in mind these are based on single samples from each month, so the data is very "noisy". If I were better skilled in MongoDB, I could pull every sample that was at 90% and graph it. But I'm horrible with it, and especially the nested document work that has to be done from TeslaMS.


I suspect I had a major software upgrade occur in Feb, 2014, for example, when the range jumped from 225.9 to 240.1 from Feb-Mar. In addition, the high June, 2014 number was immediately after a week of range charging every day while on vacation, probably at the best balance the pack's had in a while.

Great analysis. So there is some seasonality.

 

[FlasherZ]

EDIT: I pulled some more data back to January, 2014 and here's what it looks like... keep in mind these are based on single samples from each month, so the data is very "noisy". If I were better skilled in MongoDB, I could pull every sample that was at 90% and graph it. But I'm horrible with it, and especially the nested document work that has to be done from TeslaMS.

I suspect I had a major software upgrade occur in Feb, 2014, for example, when the range jumped from 225.9 to 240.1 from Feb-Mar. In addition, the high June, 2014 number was immediately after a week of range charging every day while on vacation, probably at the best balance the pack's had in a while.

View attachment 101225

Found it... on Feb 22 (2014), I had an upgrade that made my 90% jump from 225.8 to 236 in the following days.

 

[RJ Dibble]

Once again this is the OP of this thread.
Yesterday morning, as typical after a week or so I reached a new 90% low of 248 (down from 258 when delivered end of September)
Not a happy camper!!

Ron

Welp, same here... down one more mile to 244 (from 258). Took it in for service on a different issue (turn signals not
working-Tesla replaced the 'body module') and service guy gave the same response that we got
the first time we asked about the drop in range: that it is due to temperature. It has been colder here but I really do not think
that that is the cause.
Guess we will just have to keep on keeping track

RJ

 

[MorrisonHiker]

Oops. Looks like RJ double-Dibbled. :wink:

 

[RJ Dibble]

Ha Ha..like I haven't heard that before :wink:

 

[FlasherZ]

My seasonal loss (apparently due to temperature) appears to be about 3% or so. 248 is just a bit more than 3%, while 244 is more. I would watch it over the next few months and check back in around Mar-Apr (where my peak is).

 

[gway]

I am likely placing an order this week. My thinking has been to get the biggest battery I can get (to reduce 'range anxiety', help with resale etc). But the Tesla sales guy and this possible degradation issue has me further rethinking things. I don't really "need" the 90 so I was on the fence from a cost/benefit perspective already and now wondering if sticking to the 'tried and true 85' is the smart play at present given the relative 'newness' of the 90? Any thoughts appreciated.

 

[Galve2000]

I think the algorithm that calculates rated range as been optimized by the gods at Telsa for the 85 pack and needs to be "modified" for the 90 pack. I think they just ported same from one battery to the other and it is giving a poor estimate of range for the newer 90 battery.

i have an 85D and no longer get 241 regularly on a 90% charge. but once in a blue I get 242 or 243 (WOW!!!) on a 90% and boy do I feel like a kid at Christmas on those days. Not sure what I would do with an extra whole 2 miles of range -- and then I remember -- it's all an estimate, and I go about my day...

 

[apacheguy]

I am likely placing an order this week. My thinking has been to get the biggest battery I can get (to reduce 'range anxiety', help with resale etc). But the Tesla sales guy and this possible degradation issue has me further rethinking things. I don't really "need" the 90 so I was on the fence from a cost/benefit perspective already and now wondering if sticking to the 'tried and true 85' is the smart play at present given the relative 'newness' of the 90? Any thoughts appreciated.

To be honest, if I were placing an order right now I would get an 85D. I'm very interested to see how the whole 90 thing plays out.

 

[msnow]

My seasonal loss (apparently due to temperature) appears to be about 3% or so. 248 is just a bit more than 3%, while 244 is more. I would watch it over the next few months and check back in around Mar-Apr (where my peak is).

When many of us started noticing the loss it was pretty hot temperatures. For example I'm in Southern California and I started at 258 @ 90% and 287 @ 100% on 9/16 (one day old car) but lost 1 mile per week after that and the temperature was in the mid 90's. About one month later (still hot temperatures but 7.0 downloaded) I dropped to 253@90 and 282@100. Now my car is 2 months old and the temp has been between 65-75 and I'm at 251@90 and 280@100. If it's temperature related this doesn't make sense. The good news is I'm not dropping a mile a week anymore more like 1/3. The bad news is I've lost half of the 6% range increase I got for upgrading to the 90D.

 

[sorka]

My 90% on my P85D with 19" wheels is 226 in the 40s vs 226 a few months ago in the 80's. I don't think temperature is effecting my rated range but my estimated range on VT is dropping as the temperature drops.

My 90% when brand new was 227 back in March. I have 12K miles now.

 

[Canuck]

The bad news is I've lost half of the 6% range increase I got for upgrading to the 90D.

Maybe, but maybe not. It might still be there but just not showing it to you.

 

[jdw]

The bad news is I've lost half of the 6% range increase I got for upgrading to the 90D.

The 85D would have had losses also ... 258 to 253 is about a 2% loss. While that does seem a little high for 1 month, it is not that far out of line with 85 batteries. In any event, I wouldn't worry unless it continues.

 

[msnow]

Maybe, but maybe not. It might still be there but just not showing it to you.

Sure hope you're right and it's just a software/algorithm thing.

The 85D would have had losses also ... 258 to 253 is about a 2% loss. While that does seem a little high for 1 month, it is not that far out of line with 85 batteries. In any event, I wouldn't worry unless it continues.

That was 3 weeks ago and I'm down to 251 now. Someone else upthread is at 250 from 257/258. Loss rate seems to be slowing for me now though. (Fingers crossed)

 

[FlasherZ]

Found it... on Feb 22 (2014), I had an upgrade that made my 90% jump from 225.8 to 236 in the following days.

Correction: this was my battery pack replacement due to contactor failure, when the graph corrects upwards.

I posted new graphs with all data points here:
Displayed Range and Seasonality

One conclusion to draw is that some range loss might be due to seasonality.

 

[rawn77]

It's me the OP again.
So it's been about a week since mo 90% charge was 248 (I was pissed then)
Tonight is another new low; 247.
Now, I'm really getting ...... well you know!
Meh!!!!!

 

[Poison Dart Brew]

Really?? Did everyone do this with there ICE car? NO... There is no technology in the tanks to measure exactly what is left in your tank of petro (although there could be) to see exactly how many miles are left within a few miles. Really when it gets to 40 miles left in a ICE car, I worry that I might run out soon. When I fill a petro car it can vary greatly as much as 50 miles (depending on previous driving). As far as measuring the energy left in a battery, this is even more complicated than measuring a liquid in a tank. People complaining about a few miles of difference in a 90% charge, that can't truly be measured, and when they had an ICE car really didn't pay any attention to the 50 mile difference they may encounter drives me nuts. Ok I am off my soap box now. time for another beer. Cheers!!

 

[msnow]

Poison Dart - you'd have to read the previous threads before jumping to a conclusion.