Decreasing rated range.

[SFOTurtle]

A lot of what we think comes from Tesla ends up coming from someone who talked to someone at Tesla. I am not making representations here, I'm simply asking a question based on what I read over at Tesla Motors forums. There is no need to jump all over me for asking a question, we come here for answers don't we?

Here is the thread: How long can I leave it charging? | Forums | Tesla Motors

Reference post by nickjhowe, who bases his advice on this thread: Tech Talk Revelations | Forums | Tesla Motors

I'm just trying to learn like the rest of you.

Hey, didn't mean to jump all over you (and didn't think I did, although the use of multiple question marks could have been perceived as such), but just wanted to know if there was any official announcement by Tesla -- in writing -- that charging with a 110v was bad for the battery since this really seems beyond the pale for Tesla not to have very clearly warned people there would be any problem charging at low amperage. If that were the case, one would have to imagine there would be warnings left and right about doing that -- at least similar to what is said about range charging or leaving the car sit with a completely full SOC.

I read through the other threads and it's hard to tell who is saying what and what level of experience they have with the battery pack, but to me some of the posts look a lot like the game of telephone with people reporting what someone else said, and perhaps missing a step or perhaps the person who said it really didn't know what was being said. It just doesn't make any sense why Telsa would recommend 40A charging above all other amperages, nor were any reasons provided as to how it related to the health of the battery or if they were, I missed those.

 

[qwk]

I will PM one person who told me that, and give him the link to this thread. Not sure if (s)he will reply or not. I'm down around 254 now, by the way, as measured with 4.5.

Are you getting the 254 range charge number right after charging stops?

 

[Owner]

good points about the high numbers likely being full range charges. Hadn't thought about that one. I initially though the 203 number was an outlier and likely a typo from 230. I decided to include the data as is without interpretation in the interest of science.

For the "Rated Range vs. Distance 85kWh Battery" chart...
I have high confidence your > 250 data points are Range/Trip (100%) and your < 250 data points are Standard/Daily (92/90%).

The "~8k, ~205" data point in that chart is somewhat troubling.

 

[cinergi]

Are you getting the 254 range charge number right after charging stops?

My car (.61, 14k miles) is now topping out at 251 range mode charge (as observed immediately after it's done charging). 219-220 standard mode. Something happened recently (not sure it was tied to an update) where I dropped from 232 to 219 in one day. I have a message into service about it, though I have yet to hear back.

 

[Owner]

I do think I have a few erroneous data points and I included all data to be scientifically accurate. But I think most people who would take the time to fill out a survey do it accurately. Almost everyone was on 4.5. I doubt too many folks filling this out didn't understand the slider or the question, although perhaps a handful did not.

My own car I filled it all the way up outside of range and I get 235 and it can vampire down to 232. I have 5K miles and I don't think my battery is that degraded.

So to me there are still a ton of mysteries out there. Why the rated range varies so much with 85K batteries with similar mileage with a full non-range mode charge? Is it the battery measurement methods are not accurate? The theory that many Tesla employees did say that it depends upon your driving habits has been disproven for at least long range driving habits.

Owner,

I took a look at your results, and it looks like you have a lot of bad data coming into your survey. Because:

1. Beginning with 4.5 there are various charge level settings (50-90% SOC "standard range" and 90-100% SOC trip range) and with 4.4 and prior there was only a standard charge 93% SOC and Max Range 100% SOC

2. Vampire power draw reduces the displayed range slowly after the end of a charge so if my charge completes at 9pm, and I look on the display the next morning my number will have fallen from 255 at 9 PM to about ~248 at 9am.


I hope you understand the as far as anyone knows, NO ONES full range has decreased from 270s down to 225, you are just comparing various states of charge along with battery degradation on top of that.

Peter


Followup: As a note, it's not surprising that owners are confused by all this, as we are now finding, the "rated range" energy unit can vary from car to car, mileage is decremented at a even different number, and there has been what appears to be noticeable degradation of the battery in many cars decreasing the range by 10-25 miles.

 

[Gear]

People who are reporting recent drops after the latest updates, I'm curious to know if you have a baseline to work with in terms of how it relates to miles of range used. For instance, if you drive the same route to work every day and you usually use 50 miles of range from the rated range number, are you still seeing the same number used after the update or is it less? My point is that maybe there is simply a more accurate algorithm being used for the rated range number, perhaps more closely based on past usage.

 

[Owner]

This "short term driving habit theory" I don't think has really been put to the test. Would be interesting if someone did this. I don't have any regular routine :biggrin::smile::tongue: so it would be a pure experiment on my part.

Any volunteers?

People who are reporting recent drops after the latest updates, I'm curious to know if you have a baseline to work with in terms of how it relates to miles of range used. For instance, if you drive the same route to work every day and you usually use 50 miles of range from the rated range number, are you still seeing the same number used after the update or is it less? My point is that maybe there is simply a more accurate algorithm being used for the rated range number, perhaps more closely based on past usage.

 

[SFOTurtle]

good points about the high numbers likely being full range charges. Hadn't thought about that one. I initially though the 203 number was an outlier and likely a typo from 230. I decided to include the data as is without interpretation in the interest of science.

Or could it be that the 203 was a range charge from a 60?

 

[Owner]

Just checked, the 203 responder did indicate they had a 85. Hey if I got 10% erroneous data, I think that's fine. The results are still perplexing even with the outliers.

Or could it be that the 203 was a range charge from a 60?

 

[AmpedRealtor]

Hey, didn't mean to jump all over you (and didn't think I did, although the use of multiple question marks could have been perceived as such), but just wanted to know if there was any official announcement by Tesla -- in writing -- that charging with a 110v was bad for the battery since this really seems beyond the pale for Tesla not to have very clearly warned people there would be any problem charging at low amperage. If that were the case, one would have to imagine there would be warnings left and right about doing that -- at least similar to what is said about range charging or leaving the car sit with a completely full SOC.

I read through the other threads and it's hard to tell who is saying what and what level of experience they have with the battery pack, but to me some of the posts look a lot like the game of telephone with people reporting what someone else said, and perhaps missing a step or perhaps the person who said it really didn't know what was being said. It just doesn't make any sense why Telsa would recommend 40A charging above all other amperages, nor were any reasons provided as to how it related to the health of the battery or if they were, I missed those.

No worries, I just am confused because I would also like to do what's "best" for long term battery life but am torn between following recommendations here or following Tesla's general recommendation not to worry about it and just keep it plugged in. You guys are all very knowledgeable and I'm following this thread with great interest.

 

[Owner]

I think don't worry about it outside of avoiding range charges or keeping daily charges reasonably low.

I babied my Roadster and put it in "vacation mode" a lot even when I was driving it for short trips. After four years, I can't say my battery was above average. Probably right where it should be for the mileage.

I also think with the 85, its useful life will be quite long because it will still be useful when it degrades to a 60....

No worries, I just am confused because I would also like to do what's "best" for long term battery life but am torn between following recommendations here or following Tesla's general recommendation not to worry about it and just keep it plugged in. You guys are all very knowledgeable and I'm following this thread with great interest.

 

[qwk]

Here is mine right after a 90% standard charge. I'm on .59, and have only range charged one time. It read 272 rated after about an hour of the charge being finished(firmware 4.4).

My car (.61, 14k miles) is now topping out at 251 range mode charge (as observed immediately after it's done charging). 219-220 standard mode. Something happened recently (not sure it was tied to an update) where I dropped from 232 to 219 in one day. I have a message into service about it, though I have yet to hear back.

 

[aviators99]

Are you getting the 254 range charge number right after charging stops?

Yes. I have logs for every 60 seconds from when it started charging.

 

[bluetinc]

Hi QWK, how many miles are there on your car?

Here is mine right after a 90% standard charge. I'm on .59, and have only range charged one time. It read 272 rated after about an hour of the charge being finished(firmware 4.4).

Mine tops out at 255 now (18k miles) it did charge up to 275 when new (under 4.0 software)

I discarded most of the hand waving about software changes the other day when I had a new loaner car with 300 miles on it, 4.5 .61 and charged all the way up to 275.

Yes. I have logs for every 60 seconds from when it started charging.

 

[Todd Burch]

Has anyone sent an email to ownership about any of this to get an official response in writing regarding apparent loss of range and technique for battery balancing? If not I'll send one off perhaps tomorrow.

 

[cinergi]

Has anyone sent an email to ownership about any of this to get an official response in writing regarding apparent loss of range and technique for battery balancing? If not I'll send one off perhaps tomorrow.

not to that extent, but service just got back to me and said that seemed low ... so we'll see where this goes. You can write ownership but I can almost guarantee what they'll say (I'd do it anyway, because if this is an issue, we need to start with ownership and go up from there and not just bypass ownership)

 

[Owner]

I'd love to hear a succinct clear response from them about rated range. If you want to take the lead in contacting Tesla officially, I'm sure many would appreciate it.

Has anyone sent an email to ownership about any of this to get an official response in writing regarding apparent loss of range and technique for battery balancing? If not I'll send one off perhaps tomorrow.

 

[aviators99]

I'd love to hear a succinct clear response from them about rated range. If you want to take the lead in contacting Tesla officially, I'm sure many would appreciate it.

I've been talking to ownership about this for months. I've consistently heard that rated range is not based on driving. I've consistently heard that my loss (around 20 miles now) is as expected and that they've checked my battery and nothing is wrong with it.

 

[brianman]

I've been talking to ownership about this for months. I've consistently heard that rated range is not based on driving. I've consistently heard that my loss (around 20 miles now) is as expected and that they've checked my battery and nothing is wrong with it.

Do they have any updates on the battery replacement plan?

 

[Lloyd]

We should expect from the battery curves we have been presented with: 3% loss of range the first year, and 1% for every year after. I would consider normal +/- 2% at the minimum.