Dramatic Loss of Range

Could be a pack balancing problem - have you followed recommended procedure? It involves fully charging then fully discharging the vehicle a few times, some owners have gained 10 or 20 miles doing this.

This is especially important if you rarely discharge the vehicle fully, as it allows the car battery management system to fully gauge cell capacity. Without this information, it is making a safe estimate, so the cells do not get fully discharged.

It could also be a calibration problem. My rated 90% charge had decreased a few kilometres from when the car was new (8500 miles now), but one day I really pushed the limits of the battery and drove a couple of kilometres below zero range. The next day my 90% charge was higher than I had ever seen before. If one never draws the battery down low, the remaining energy calculations will probably be more and more imprecise with time.

This discussion emphasizes what I have wondered for a while: Does the indicated range actually reflect reality? The only way someone might know is if they ran a certain route that used most of their range, under the same conditions. How is anyone going to do this?

We have been told that the battery drops a small (10?) percentage at first, and then s-l-o-w-l-y continues to drop over the rest of its life. But I have noticed that about every time we get a new OTA update, the displayed range drops. I can't believe that this display is accurate. It is a calculation. The displayed range differs if I charge at 100 feet elevation, or if I have driven up the mountain to my home and charge there. It takes into account my driving "habits" of the last 30 miles, the habit being sucking large amounts of power to drive uphill 1000'. Those habits may also reflect winter driving, battery heating, cabin heating, which also suck power.

Since I don't expect Tesla to divulge any complicated formula, all I can say is I don't believe it. I plan to do a drive next month, where I need to go 230 miles with a 2000 foot elevation change. I remember what I did last year. Let's see if I make it again this year.

Rumor has it that somewhere down the road, we will be able to choose to display percent of charge. I can see that driving to zero charge, and then maybe more, and then doing a full range charge (slowly, at maybe 30 amps) would give the computer a better chance to know where empty and full might be. But as far as giving you more range, I'm not so sure. It probably, more likely, just changes the numbers in the calculation.

roblab said:

This discussion emphasizes what I have wondered for a while: Does the indicated range actually reflect reality?

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Both rated range and ideal range are educated guesses. Tesla adjusts this from time to time. From what I've read you should expect 5% reduction the first year and about 1% each year after that. The last range charge I did a couple of weeks ago was 260 miles at about 19,000 miles. One year was a week later. It wasn't a full range charge though, there was still some to go. So depending upon what you think the initial value is (265, 267, 274 are all numbers I've heard) I've lost 2%, 3% or 5%.

Pack balancing only happens during a range charge, but also, capacity measurement changes only happens on a deep cycle, at least according to a Tesla service advisor when we spoke of this issue a couple of weeks ago. Therefore, your pack's real capacity can only be determined after doing a range charge, drive all the way down as far as you can, then range charge again. Not so clear is how long to leave it at range charge, and if one cycle of this is enough. Also, it is not clear that this is anything more than a cosmetic issue if you don't need the total range. It is also apparent that this is something Tesla is still working on to improve the situation.

246 is awesome. Not really but my pack replacement on my car that only has 4700 miles on it only gets 240 at max range.

techmaven said:

Pack balancing only happens during a range charge, but also, capacity measurement changes only happens on a deep cycle, at least according to a Tesla service advisor when we spoke of this issue a couple of weeks ago. Therefore, your pack's real capacity can only be determined after doing a range charge, drive all the way down as far as you can, then range charge again. Not so clear is how long to leave it at range charge, and if one cycle of this is enough. Also, it is not clear that this is anything more than a cosmetic issue if you don't need the total range. It is also apparent that this is something Tesla is still working on to improve the situation.

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And driving till you can't drive--isn't that what we're not supposed to do, bad for battery, etc.? Contradictory suggestions around here and from Tesla. ;-)

kendallpb said:

And driving till you can't drive--isn't that what we're not supposed to do, bad for battery, etc.? Contradictory suggestions around here and from Tesla. ;-)

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It's not problematic if you only do it occasionally, and (more importantly) charge it up again right away.

But I also think it's cosmetic. You'll maybe get higher (and more accurate) numbers on the display, but not more range. Just a display calibration. If you don't do this, and your range charge number has decreased, the net result is probably just a bigger buffer below zero.

As others suggested, this is most likely due to a slightly imbalanced battery. This all the more so as you stated: "My car is usually charged to 170-180 miles for daily use." For Roadsters their "Standard" charge is the minimum for balancing to start, provided the car is left plugged in long enough after charging has finished - for a couple of hours at least some believe. Roadster owners also noted that lower rates of charging tend to lead to higher mileages indicated after charging stopped. In my case charging at 32A may stop at 275 Km (Standard Charge) and 10A will go to 285-290 Km.

OP - How did the road trip on the range charge go? Did the loss of range alter your trip any?

I have similar usage in a not quite as old car with probably 12-14 range charges. My max charge is around 245 now. I'm a little disappointed to see the number change like that but I'll reserve the outrage for later if a 10% annual loss of range continues - and I doubt it will. One of the factors in my purchase decision was the testimony of charge loss from Roadster owners (Thanks Roadster owners!). When I first got the car a 245 mile max range would have been a big deal because there were zero superchargers within 250 miles of me. Now there are 5, 4 of those within 200 miles. I've only range charged once or twice in the past 2-3 months for cold weather day trips in which I wanted tons of range cushion. The decreased max range hasn't altered my driving any so I'm willing to take a wait a see approach and find other things to worry about.

Super Gizmo said:

I have a P85 VIN:1586 bought in 11/2012. I have close to 16K miles on the car. I live in the Bay Area where the temp today is approximately 70. Last night I did a range charge for only the 4th time since owning the car and I was shocked to see that the Rated Miles on a full charge are only 246. I never let the battery get down below 100- 140 miles. I only used the Superchargers on the way back from LA last year on I-5 because the ones on 101 were not active at the time. When I Supercharged on that trip, I only charged to 90% or less. My car is usually charged to 170-180 miles for daily use. My 90% Rated charge is down to 212. I have been doing all the right things espoused by Tesla - like leaving the car plugged in most of the time so I am very disappointed to see the loss in range. My life time Wh per mile is 316.
I feel this is unacceptable. I have taken care of the car and bought 8 year extended warranty and maintenance plans, had the car serviced on time. I don't hod rod or race the car because I have a bad back and have had neck surgery. I think it is time to get in touch with the higher ups in Tesla and find out what the hell is going on here. This is very upsetting to say the least.

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There are a couple of threads about range loss. It seems like the "A" battery packs degrade much worse than the "B" packs.

roblab said:

I can't believe that this display is accurate. It is a calculation.

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I agree and am convinced that all of the reported range loss is related to the software algorithm, not actual and real loss of range.

The one and only time I max charged to 100% (after 6 months and 6,000 miles) my car showed 301 ideal miles of range. I was then able to drive 15 miles on a flat freeway, at 75 MPH, at about 80 degrees, before the range display dropped by a single mile. This experience tells me that the algorithm is flawed. How could I drive 15 miles and have the range estimate drop only by a single mile? Where did those 15 miles come from?

Clearly there is range in the battery that is not being accurately reflected in the display.

AmpedRealtor said:

I agree and am convinced that all of the reported range loss is related to the software algorithm, not actual and real loss of range.

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I'm going to have to disagree with you here, or at least what you seem to be saying. Read just the underlined. Read alone that seems to be suggesting that every Model S battery owned by a TMC member has experienced zero degradation. I find this difficult to believe. And from that I'd like to ask...

@Experts on TMC: We should probably start an "expectations" setting post or wiki for degradation for Model S.

Example 1: Assume Tesla chose the worst 2011 technology chemistry for batteries. What do the degradation curves look like for (a) an always-plugged-in garage queen vehicle with < 200 miles on it after 1 year, (b) a "typical" daily driver after 1 year, and (c) a 40,000 mi/year vehicle after 1 year.

Example 2: Assume Tesla chose the best 2011 technology chemistry, miraculous combinations of 2011 additives, and prophetic BMS technology. Same (a), (b), and (c) questions from example 1.

Use whatever reasonable simplifying assumptions you'd like. Use Roadster charts as a basis if you'd like. Thanks!

I think it would go a long way for people to look at the chart of the two examples, see that their vehicles are much closer to 2 than 1, and relax a notch.

jkirkebo said:

It's not problematic if you only do it occasionally, and (more importantly) charge it up again right away.

But I also think it's cosmetic. You'll maybe get higher (and more accurate) numbers on the display, but not more range. Just a display calibration. If you don't do this, and your range charge number has decreased, the net result is probably just a bigger buffer below zero.

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Bigger buffer below zero? Perhaps, but who is going to rely on that assumption? I'd rather not put my family through this.

So, Super Gizmo, have you brought your car in for service yet?

You posted in another thread -

"If my problem is not addressed by the Service Center when my car is taken in for this issue and I am not given a clear explanation in writing, I will leave no stone unturned to get this out in public through media, news releases or whatever means necessary and this is no idle threat."

Wow. I'm down that much as well and didn't realize contacting the press was an option. Sounds like an out of balance pack as well. I did a range charge and let it sit overnight and that helped. Definitely let us know what Tesla says.

dsm363 said:

Wow. I'm down that much as well and didn't realize contacting the press was an option. Sounds like an out of balance pack as well. I did a range charge and let it sit overnight and that helped. Definitely let us know what Tesla says.

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Well this looks like a great time to finally prove or disprove the rebalancing theory. Good luck on getting real clear instructions e.g. exact steps, number of times to fully charge and discharge etc. You and SuperGizmo should ask for a clear instruction list (step by step) and see if it helps. I'll start by sharing what my service center told me to do when I questioned my daily range charge level.

1. Do a 100% "trip charge" Let it sit for at least 2 hours.
2. Drive the car until you get it down to 20% of the original total and let it sit for 2 hrs before charging again.

That's it. Not sure if a single run through is suppose to fix everything or what. I don't know if this is the rebalancing procedure touted by many on the forums but it is what my service center instructed me to do. I didn't see any change but my daily 90% charge is about 220-228 miles. Max range charge is 257 I have 12k miles. I questioned my charge levels when I noticed others on the forums reporting higher ranges and after seeing a friends new car get 250 on a daily charge. I wonder what your center will tell you to do. Have they actually looked at your car to see if anything is wrong? They did look at mine and said there is nothing wrong. You've gotta give them a chance to fix it if it is truly bad. They do keep batteries on hand just for such occasions.

My wife and I have just returned from a 800 mile Florida road trip in our Model S #16924. We were able to charge up to 266 miles before departure. It was only the third time we've done a range charge, the others charged up to about the same.

We charged up to 260 miles at the St Augustine Supercharger with a little bit to go, and to 269 on 120v before leaving for home.



The longest leg on our trip was 230 miles, and we arrived with 31 miles of range displayed. We were driving 50-55mph on country roads in the rain, temps 55 to 65 degrees.

I blogged about the trip here.

I keep the car plugged in at home with the UMC and a 14/50 plug, I always charge to the default 90% level. If I"m taking a trip and using a range charge, I schedule the charge to finish just before departure. I'm very happy with the car and have noticed no range degradation in 7000 miles.

FWIW, I did two Supercharger range charges yesterday, the last one to completion. (Start was around 130 rated miles remaining in both cases)

20,200 miles, 12 months.

IDEAL: (300-293)/300 = 2.33%
RATED: (265-259)/265 = 2.26%

B battery

The trip was Plano, Rockdale, Plano stopping at the Waco Supercharger.