Decreasing rated range.

[MassX1317]

We have been getting somewhere around 205-207 at 80%.

The last range charge was 257-258 but my wife said she drove for about 7 miles before the miles started dropping off.

When we are done driving for the day we try to charge to 50%. At 3-4am we will start the charge to get us to the approximate miles we need for the day to get us down to 50%.

We have over 12k miles on the Model S.

 

[ckessel]

Turning range mode off dropped the estimated range by a couple miles shortly after turning it off (without driving), so it's important to include that setting whenever you post your range.

Huh? Range mode shouldn't have any impact at all on the range reported. Range mode is just a voluntary crippling of certain accessories (like the fan) to avoid undo energy consumption. It shouldn't have anything to do with the range reported by the car as that's only related to the kwh in the battery.

 

[mknox]

Here's two weird things I've noticed... in case it has any relevance here:

1. Sometimes the Rated Range number on the dash will be 1 or 2 miles different than what is shown on the 17" when you bring the battery screen up.

2. Often when I pull off the highway and park for a half hour or so, my car will have as much as 5 Rated miles more than when I stopped. This happens when it is just parked and not plugged in.

 

[tomas]

Huh? Range mode shouldn't have any impact at all on the range reported. Range mode is just a voluntary crippling of certain accessories (like the fan) to avoid undo energy consumption. It shouldn't have anything to do with the range reported by the car as that's only related to the kwh in the battery.

Not so. kWh is numerator. Expected avg usage is denominator. With functions crippled, expected usage goes down and rated range goes up.

 

[nanimac]

Here's two weird things I've noticed... in case it has any relevance here:

1. Sometimes the Rated Range number on the dash will be 1 or 2 miles different than what is shown on the 17" when you bring the battery screen up.

I noticed the same thing!

 

[ckessel]

Not so. kWh is numerator. Expected avg usage is denominator. With functions crippled, expected usage goes down and rated range goes up.

Again, huh?

The rated range is purely based on EPA rating per kWh. It has nothing to do with anything you select in the car. Your actual usage may change with selections, but rated range won't (or shouldn't).

 

[Tacket]

I've been charging to 90 (on my MS60) for about 2 weeks and went from 167 to 175 rated (just hit 175 this morning). I'll continue for another 2-6 weeks before going back to my usual routine.

 

[brianman]

Here's two weird things I've noticed... in case it has any relevance here:

1. Sometimes the Rated Range number on the dash will be 1 or 2 miles different than what is shown on the 17" when you bring the battery screen up.

2. Often when I pull off the highway and park for a half hour or so, my car will have as much as 5 Rated miles more than when I stopped. This happens when it is just parked and not plugged in.

I've never seen either of these in my car.

 

[qwk]

Again, huh?

The rated range is purely based on EPA rating per kWh. It has nothing to do with anything you select in the car. Your actual usage may change with selections, but rated range won't (or shouldn't).

It shouldn't, but does happen. I'm sure it's some kind of software bug. With FW 5.8, both screens read the same range, now with 5.12 the dash reads the higher number, and the 17" screen reads the normal range number for me. If you toggle between the two modes, and wait a few minutes, you guys should have the same behavior.

 

[rlang59]

Huh? Range mode shouldn't have any impact at all on the range reported. Range mode is just a voluntary crippling of certain accessories (like the fan) to avoid undo energy consumption. It shouldn't have anything to do with the range reported by the car as that's only related to the kwh in the battery.

In my car if I turn range mode on the rated range goes up by 3-4 miles.

- - - Updated - - -

Here's two weird things I've noticed... in case it has any relevance here:

1. Sometimes the Rated Range number on the dash will be 1 or 2 miles different than what is shown on the 17" when you bring the battery screen up.

2. Often when I pull off the highway and park for a half hour or so, my car will have as much as 5 Rated miles more than when I stopped. This happens when it is just parked and not plugged in.

I have seen both of these as well.

 

[tomas]

Again, huh?

The rated range is purely based on EPA rating per kWh. It has nothing to do with anything you select in the car. Your actual usage may change with selections, but rated range won't (or shouldn't).

Thx @QWK for explaining both.

I actually think this brings up a much deeper question. Is the denominator of the "rated range" calculation fixed since the EPA loop tests, or not? And, is there one and only one value of the denominator: presumably based on the average Wh/mi from the EPA loop test? Or are there 2 (one for each toggle of range mode switch)? Or are there other factors (historical usage of the driver, temperature, etc.) baked into the calculation?

One thing I know for certain: my rated range has changed perceptibly numerous times after firmware updates. That could all stem from messing with the numerator: different ways of estimating the number of kW in the battery, changing the reserve on either end (below 0, above 100). Or, it could include some messing with the denominator. I know that the number posted on the window sticker and in advertising is sacrosanct, and has to tie back to the EPA tests. But, not sure the number on the dash is locked down like that.

I'm not hung up on this, not going to lose sleep over it! But I think it is interesting debate -- which is all it is, absent the real facts from Tesla.

 

[ckessel]

It shouldn't, but does happen.

Well, that's really unfortunate. That means Tesla isn't calculating range based on the EPA rating. It's calculating range based on some unknown algorithm that apparently varies in for unknown reasons. It's a small enough difference to be of little practical concern, but at a conceptual level I want to believe that when my display says "147 rated range" that it's always based on the same assumptions.

I'd hate to go "Oh, I've made this trip before and I know I can make it to my destination if I slow down to 60mph" and find out that, no, I won't make it this time because the range wasn't really the same "147 rated range" I saw last time do to some change in some config screen.

Anyway, mountain out of a molehill since, as I noted, it's small enough variation to be of little impact. I'd certainly call it a bug though. The "rated range" shouldn't be based on anything other than the EPA rating.

 

[qwk]

Well, that's really unfortunate. That means Tesla isn't calculating range based on the EPA rating. It's calculating range based on some unknown algorithm that apparently varies in for unknown reasons. It's a small enough difference to be of little practical concern, but at a conceptual level I want to believe that when my display says "147 rated range" that it's always based on the same assumptions.

I'd hate to go "Oh, I've made this trip before and I know I can make it to my destination if I slow down to 60mph" and find out that, no, I won't make it this time because the range wasn't really the same "147 rated range" I saw last time do to some change in some config screen.

Anyway, mountain out of a molehill since, as I noted, it's small enough variation to be of little impact. I'd certainly call it a bug though. The "rated range" shouldn't be based on anything other than the EPA rating.

I think that it all boils down to the range being just an estimate, and only an estimate.

 

[Gear]

Well, that's really unfortunate. That means Tesla isn't calculating range based on the EPA rating. It's calculating range based on some unknown algorithm that apparently varies in for unknown reasons. It's a small enough difference to be of little practical concern, but at a conceptual level I want to believe that when my display says "147 rated range" that it's always based on the same assumptions.

I'd hate to go "Oh, I've made this trip before and I know I can make it to my destination if I slow down to 60mph" and find out that, no, I won't make it this time because the range wasn't really the same "147 rated range" I saw last time do to some change in some config screen.

Anyway, mountain out of a molehill since, as I noted, it's small enough variation to be of little impact. I'd certainly call it a bug though. The "rated range" shouldn't be based on anything other than the EPA rating.

I don't think this rules out that they're using the EPA rating. As has been said many times on this forum, reading the kWh remaining from our packs isn't as easy reading remaining fuel in a tank. They could easily be using the EPA rated kWh/mi figure and just be improving the algorithm for reading the remaining energy in the pack.

 

[AmpedRealtor]

Again, huh?

The rated range is purely based on EPA rating per kWh. It has nothing to do with anything you select in the car. Your actual usage may change with selections, but rated range won't (or shouldn't).

The car is just telling you that you can travel a few miles further with your AC in range mode. I think that's fair to incorporate into the range display. I realized this little "trick" a few months ago, but it's really just for show.

 

[walla2]

More data and food for thought:

My 2012 Signature P85 with its refurb A pack just hit 9100 miles. I had a 90% charge of 227 on 5.9 and have a 90% charge of 226 on 6.0.

My original battery was a trooper. It would range charge to 257 just before it died suddenly from the clunk at 4500 miles. Degradation of range had only started on my original A pack when I started 50-70% instead of 90-93% charging the car. I also used to charge at less than or equal to 24 A @ 220V. When Tesla added the slider and said 40 A would save power, I stopped doing this and that is when the pack went from 260+ downward. I would not advise charging 50-70% ever and would charge at lower amperage if that is practical.

My refurbished A pack battery started with less range miles (250) and seems to be losing miles much more quickly. Pointing this out to Tesla indirectly and also directly has led nowhere really despite efforts to increase it back (firmware 5.8/9 was the only thing that truly helped). I suspect at the end of the day my refurb A pack had more miles on it than my original A pack (~4500).

Which begs the question, shouldn't the batteries have odometers too? Since they are the life force of the car but can be replaced, a Model S with 9000 miles but a 90000 mile on the battery isn't going to be the same as a 9000 mile Model S with a 9000 miles on the battery.

My thoughts now on preserving / maintaining pack range:
1. Charge at 90% always and every day.
2. Charge at lower amps if possible.
3. Don't attempt to balance at 100%. It didn't help (no significant or lasting effect) and may hurt things in the end.
4. Firmware changes will move the miles back and forth so don't freak if miles change between firmwares. It's apples to oranges.
5. Make replacement pack version (A, B C, D, etc.) and SOC / rated range a priority concern if you have a pack failure.

 

[MassX1317]

Charged to 90% last night, 230 on dash, 228 on center screen

 

[tomas]

Charged to 90% last night, 230 on dash, 228 on center screen

Do you have range mode on?

 

[apacheguy]

Which begs the question, shouldn't the batteries have odometers too? Since they are the life force of the car but can be replaced, a Model S with 9000 miles but a 90000 mile on the battery isn't going to be the same as a 9000 mile Model S with a 9000 miles on the battery.

Well, in theory, service is supposed to look at the CAC value of your failed pack and then replace it with an equal or better rated pack. That's the battery equivalent of the odometer. Did you ever ask Tesla for this data?

 

[MassX1317]

Do you have range mode on?

Yes, D pack, 12k+ miles