Oct 20, 2014
fred z Hi guys and gals.
Question: does anyone know for sure that there is actually extra miles built in to the battery after the 265 max limit? I had heard that there is a 17 mile bonus that is there in case one takes it to the limit before charging.
True, not true?
thanks
fred z�
Oct 20, 2014
ElSupreme Don't count on any miles after you hit zero. There are some instances of driving past zero, but plenty of people have died right after zero.
Definitely don't count on 17 miles.�
Oct 20, 2014
AmpedRealtor Also, the EPA rating of 265 miles is after driving the car until it physically stops moving. That represents the full range of battery charge that is available to drivers. Don't count on any miles past zero, and it's probably a good idea to plan your destinations to leave a 30-50 mile remaining range.�
Oct 20, 2014
apacheguy Haven't heard of anyone dying at zero. The SOC gauge actually used to show ~4% at 0 rated miles, but that was changed with one of the updates so that 0% SOC aligns with 0 rated miles. I think it's completely reasonable to count on at least 5 miles below 0 from everything that I've read. Obviously don't plan your trip that way, but if push comes to shove, you can definitely eke out a few extra miles.�
Oct 20, 2014
yobigd20 there are no extra miles after 0. several have thought such and their car's shut down right after reaching 0.
0 == 0.
0 != 17.
anybody getting extra mileage after 0 is just playing with fire.�
Oct 20, 2014
qwk FW 5.8 had a reserve of about 15 miles, but I really doubt anybody is still on 5.8. Now, zero means zero.�
Oct 20, 2014
bluetinc Fredz
We really have to talk energy here not miles, because as everyone knows, your mileage will vary, especially when the weather is bad. It gets a little complicated but the P/S85 cars are rated (when new) to drive 265 miles under the EPA test at which point the car stops moving. This equates to about 300 Wh/mi. Please note that we have seen these number vary a bit between various cars. According to a Tech response to another owner, when you are driving the cars reduce the miles remaining displayed to the driver at about a ~6% faster rate then the energy from the battery is actually used. On a long non-stop drive, you will be able to see that you need to drive about about ~284Wh/mi to have your actual miles driven equal the number decreased from the dashboard display, rather than the EPA "rated" energy usage. They then save this ~6% as reserve for the driver "below 0". This matches up with my experiences.
I have been watching where "0" is on the battery through the software versions and have yet to see it move, though they have remapped the SOC/User Display to no longer show "below 0" energy on the SOC. I don't know of anyone doing any real testing of the amount of energy available below 0 to verify this as not many like to go there!
Peter
Yobigd20 and qwk, can you point to the stories that show 0 == 0? I've never seen that story, only some where there are other mechanical issues causing the car to stop, not the battery, or ones where the person drives some distance of miles after 0, but the amount of energy being used is unclear and under conditions that would push it much higher than normal. Further, if that were true that 0 is now 0, and the car must use less energy to drive to 0 then shown necessary for the EPA testing, then it would not be legitimate for Tesla to still claim a range of 265 under the EPA test if the car can no longer make it.�
Oct 20, 2014
tom66 If there is any reserve, it's calculated in the 265 miles starting range.
Example, the car shows 265 miles but might have 255 miles real range until it goes to 0, then 10 miles below that.�
Oct 20, 2014
yobigd20 here's one thread: - Caution about Vegas to LA trip!!�
Oct 20, 2014
qwk There has never been a change in range from 265 rated miles, just how it's displayed. On FW 5.8 the yellow bar would appear at ~31 rated miles and at 50% charge it would show ~115 rated. Now the yellow appears at about 51 rated, and 50% is 131 rated miles(for my car anyway). Tesla keeps changing the algo for the rated range display.�
Oct 20, 2014
Msolomi Guys, I learned this the hard way this weekend. 0 under the new software, means essentially 0. I may have gone 2 miles, but at 0 the car gave me a message that said "pull over for safety, your car is about to shut off" and it did in fact shut off. I was counting on having an extra 5 miles to get to my house and I did not. Embarrassingly, I had to get towed to my house 3 miles away. In the past, I had driven with about 7 miles after 0. I think now 0 means 0. I'm running the last build of 6.0 (i believe its .42).�
Oct 20, 2014
AmpedRealtor You also understand that running the battery to zero on a regular basis is stressing the battery and your usage scenario will promote a higher battery degradation, right?�
Oct 20, 2014
Msolomi Of course, I understand. In almost 2 years, it has only happened 2x and this is the first time the car shut down. The prior time, I missed an exit and had to do a 110 charge. So, of course.�
Oct 20, 2014
apacheguy Thread seems to indicate they got 4 more miles. They point out that they were coasting downhill at this point, but this clearly was not the case as you would be regening and actually increasing the available energy. I doubt some of these reports as they will vary depending on how people are counting miles and driving style. Obviously, as bluetinc points out we ought to talk about kWh remaining and not miles remaining. I am still convinced there is some (but not much) of a reserve below zero. If I end up reaching 0 rated at some point and my car shuts down immediately after displaying 0, then I'll come back here and eat my words.
Huh, so perhaps this changed with 6.0? IMHO, Tesla really does need to document changes like these in the release notes.�
Oct 20, 2014
bluetinc Do you by chance have a 60? I've only tracked my 85 and a couple of other 85s, but I do know the 60 has totally different numbers. I thought I had roughed out the numbers and it didn't look like there was much of a buffer on the 60s.
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If you double check the link you will see they drove 4 miles past 0 in a 60. Perhaps you were thinking of another story?
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Oct 20, 2014
David99 I went 'over' three times. Once 1.5 miles, once 4.5 miles and once about 9 miles.
The max I got out of the battery when reaching zero was 76.5 kWh which is exactly 90% (of 85). It seems, based on stories from many other people, the car will go down to 5% battery capacity and then shut down. But it might depend on temperature as well. I never planned or counted on going passed zero, it just happened and I'm happy the car let me.
Going towards zero is bad for the battery. Once you have less then 50 miles left, I would recommend going easy on the accelerator and in general, always plan some buffer.
The problem is that most people don't pay any attention until it gets close. Then it's too late for a plan B. In reality you don't run out of juice 'all of a sudden'. If you keep an eye on battery and your remaining trip you can see it coming. If it looks like it's going to be very tight, I would highly recommend to look for an alternative, a charger way ahead of time, not just at the very end. If there is a charger 1/3 into your trip, use it if you know it might be tight at the end. It's much healthier for the battery and it will safe you from risking to be stranded.�
Oct 21, 2014
jerry33 I did that yesterday. Had three adult passengers for a 248 mile round trip with rolling hills (rolling hills accounted for about 1/3 of the trip). I had a plan B at the 3/4 mark but ended up not having to use it and arrived with 51 miles rated range showing. The App showed 255 after the range charge.�
Oct 24, 2014
giants2001 I wish this were the case. I just hit 30K miles on my 60. Woohoo. Unfortunately I had my first experience with running out of juice on a busy freeway. Not a fun lesson. I've driven between Harris Ranch and Tejon Ranch several times, and I knew there was a slight elevation gain just before reaching the superchargers at Tejon. What I had not taken into consideration this time was the new version of firmware installed on the car. So literally about 1000ft before the exit and with 4 rated miles shows on the dashboard, my car shutdown. And it was fast (about 30 seconds). I was lucky that I pulled over to the shoulder of the freeway when I did, because otherwise I might have been in a quite a bit of trouble.
After a long chat and a review of the logs with Tesla, it was determined that the car shut down early because it predicted that it could not sustain the current speed (70mph) with the amount of charge left on the battery (whatever equates to 4 rated miles). What bugs me is that they let an algorithm preemptively shut me down. I'm all for saving the battery, but not knowing what the "real" 0 is anymore really sucks.
So be careful. 0 isn't necessarily 0. It's more like 0 +/-5 (maybe 10). Which means if you dip below 10 miles of rated range, and without knowing exact state of charge, you're rolling the dice. Just thought I'd share!
�
Oct 25, 2014
yobigd20 Ouch. So 4 means 0. lol. I know someone whose shut down at I think it was 8. But yea we really shouldn't take it down below 10 or 20 really just in case.�
Oct 25, 2014
Cottonwood I don't care where the danger zone is; just tell us where to be concerned. It could be below 10 rated miles, below 0, or even below -10, but Tesla should just tell us at what point to be worried, and not change the "danger region".�
Oct 25, 2014
David99 While it is frustrating, there is no way the car can predict your upcoming driving style and energy usage, thus a prediction of how many miles are left is always guesswork. It also shows one disadvantage of batteries vs gasoline. An ICE engine can run fine and at full power all the way to the moment you run out of gas. A battery is more like a human. It gets weaker and weaker. Especially towards the end it is a good idea to go easy. Reduce speed and limit acceleration. If you go easy on the battery it will give you more at the end. Your experience confirms that. I went easy towards the end and was able to get beyond 0 a few times.
They do. At 50 miles left the battery bar changes from green to yellow, then to red at 30 miles. Red = danger zone. red = be concerned. Having less than 10 miles left and gunning it uphill at 70 mph = pushing it.�
Oct 25, 2014
apacheguy Double take, what?! The car shut down while it was still showing range? This is simply unacceptable, IMO. Below 0 anything is fair game, but above 0 I don't care what some stupid algorithm is saying. This does not instill a great deal confidence. I have arrived twice before at a SpC where it was close (<10 miles showing), but I knew I would make it both times because I trusted the range numbers and calculated that I would make it before hitting zero.
Disagree. It knows the pack voltage and it knows the trigger for flipping the battery contactors. This is a precise measurement. No reason to still be displaying range when it knows it has exceeded the threshold.�
Oct 25, 2014
David99 Towards the end, the battery is pretty weak. You can either still go for a while driving gently or you can push up a hill at 70 mph and force the voltage drop to a critical value when the car needs to shut down to prevent damage to the battery. There is no way the car can predict your driving style. If you never want this to happen the car will have to assume worst case scenario (uphill fast driving) and subtract the last 20 miles by default. This takes away perfectly usable range for those who drive carefully at the end. Nissan implemented it in their Leaf by switching to 'turtle mode' where the car will only go with very limited power to keep the battery safe yet allow you to use the last little bit of juice.�
Oct 25, 2014
bollar The Model S also does this, though. Shortly after the battery bar turns red, the maximum power available begins to drop -- to protect the battery, of course. But I also think it should ensure that you don't get an emergency power down with 4 rated miles remaining.
�
Oct 25, 2014
apacheguy Right, exactly. It's not a question of predicting how far one can go. There's no guess work in play at all. If the car is still displaying rated range > 0, it should not shutdown. Period.�
Oct 25, 2014
Seattle They need to adjust their algorithm to go back to the old system where there was a buffer past 0. These reports are troubling, but I wonder if we have the full story. When you get down close to 0, the available power also reduces. But the old system was better. Why didn't the car reduce the max speed instead of just cutting the driver over?
Not to be mean (no doubt after saying this, I'll run out tomorrow), but I can't imagine trying to drive 70 mph when you are almost at 0. The one time I got almost to 0 I was driving slower, trying to stretch it out.�
Oct 26, 2014
apacheguy @giants01 says he was 1000 ft from the cutoff to the SpC. If I was still showing 4 miles and knew that I only had a couple thousand feet to go, I wouldn't be worrying too much about conserving energy. At that point I'd be thinking "I totally got this."
Agree with your other point that the algorithm should change to allow a small buffer below 0. If we have cars shutting down before they even reach 0, then it's clear that someone was far too aggressive in changing the reserve.�
Oct 26, 2014
Larry Chanin I'm guessing that version 6.0 of the firmware is now adding roughly 5% of rated range in it's current range calculation over previous calculations.
When my Model S was new a full range charge was 265 rated miles. Over time a full range charge dropped to 258 rated miles. Now following version 6.0 my last range charge was 271 rated miles.
If Tesla is now more aggressive in calculating range, it would not surprise me if now there is little or no reserve left when the car displays zero range.
Larry�
Oct 26, 2014
SarahsDad One data point that goes against adding range to the 6.0 firmware is my recent drive from full to empty - used an observed 74.1 kWh on two separate occasions pre-6.0, but this time full to zero yielded only 71.7 kWh. This suggests that there is actually more hidden beneath "0" post-6.0. Or my battery is suddenly losing capacity... Max range charge for all three trips.
Aug 21 2014 (Pre-6.0)
Sept 6 2014 (Pre-6.0)
Oct 24 2014 (Post-6.0)
�
Oct 26, 2014
bonnie If anyone tries to convince you that there is a 'bonus' reserve that you can count on, make sure you have their home phone number and an agreement that they'll come pick you up if you dip below 0.
Then you'll see how sure they are that the reserve is something you can count on. (I wouldn't.)�
Oct 26, 2014
Cottonwood I don't care how much hidden reserve is there as long as the car will drive reliably down to 0 rated miles. I have gotten very good, in hypermile situations far off the Supercharger Highway, at adjusting my speed and driving style to ensure that I arrive at the next charge location with positive miles in the battery. Mine is a simple request, if the battery indicates 1 or more rated miles present, the car should keep driving, and there should be no sudden jumps in rated miles other than those caused by me using energy to drive, climb hills, heat, etc the car.
What scares me is the report of a Model S stopping when it had a few miles left. If there is uncertainty in the calculation, Tesla should just put all of that uncertainty below 0. If the "hidden" energy is between 17 and 0 rated miles below 0, that's fine, I just want Tesla to put all the required margin below 0, so that I know that the car will continue operation (with reduced power) down to 0 miles.�
Oct 26, 2014
Larry Chanin You have driven your Model S to zero on three occassions followed by maximum range charges? Maybe a sudden loss of capacity after the third isn't so far fetched.
Larry�
Oct 26, 2014
SarahsDad I only range charge about once a month. I've driven down to zero almost a dozen times over the last year after a range charge. Total kWh used has always been 73.5 - 74.5 with 0 miles remaining, until this most recent post-6.0 trip. (Curious/obsessed with end-of-charge behavior, but never driven more than 1-2 miles past zero. After reading about the shutdown at 4 miles remaining I might not be so aggressive in the future...)
Still pretty good range charge numbers at 15K miles though...
�
Oct 26, 2014
SmartElectric Completely acceptable. Don't drive on empty. Simple.
The Smart ED (and MB B class ED) have a "power meter" which has 3 stages, one each for full power available, then reduced power and finally minimum power available. Depending on the situation it is a good indicator of the estimated stress that can be placed on the battery. In -24C cold soaked for 9 hours last winter, my Smart ED started in minimal power, and warned me that the battery needed to be brought up to temperature before full power could be used. On another occasion when I took it down to zero estimated range remaining, the power indicator dropped to reduced.
People have already reported their P85+ has lower 1/4 mile times as the battery is depleted, so Tesla has the software smarts which could be used to provide a power indicator...�
Oct 26, 2014
bollar The Model S also indicates reduced power due to low batteries and cold batteries. For the OP, the car shutdown while indicating 4 miles range remaining, which some of us believe is not desirable.�
Oct 26, 2014
ecarfan When new my S85 full charge was 265. Now it is 258 after 10 months and 18K miles. It was 258 a month ago before V6 and it is still 258 after installing V6.�
Oct 26, 2014
apacheguy Uh, no. NOT acceptable because he was NOT on empty! 4 miles != empty!
+1. Exactly.�
Oct 26, 2014
David99 I agree that is a good idea to make sure people don't get upset, but it would mean they have to very generous in what is left in the battery when it reaches 0 miles. Some driver might want to go pretty fast, so the buffer would have to be big enough to allow for that. The downside is that for everyone who drives normal or even careful at the end, that range would be lost. I would prefer the car to reduce power if necessary ahead of time if there is danger that is won't make it to 0. This way it will make it to 0 as 'promised' without compromising range. That's what I do using my foot and it helped me getting beyond 0 a few times.
I hope soon Tesla will have enough data from cars on the road that it can predict energy needed to reach a destination based on that much more accurate.�
Oct 27, 2014
scaesare I would much rather the car severely limit energy usage (and thus top speed/acceleration) and allow you to use the remaining energy than decide that it can't supply the power being requested at the moment and simply aborting.
Move that yellow energy limiter down to 30kWh if it needs to, and let me limp along for that last 1,000 feet to the charger...�
Oct 28, 2014
giants2001 Been a while since I was able to check this thread, and there is a lot of good conversation. I could't agree more with scaesare
Also, as Apacheguy pointed out, I was not at 0 miles. Therefore with 4 miles of rated range and about 1,000ft until my exit (which is all downhill afterwards) I was not concerned. In my mind, I wasn't even close to zero. That is until the car shut down. Obviously if I knew the car was going to shut down when it did, then I would have adjusted my driving well before to make sure that I was going to make it (with several miles of margin).
I get that Tesla is trying to get the "rated" miles calculation to be as accurate as possible, but as a user I'd rather have the "real" data displayed to me so that I can make the most appropriate decision to account for speed, slope, environmental factors, etc. Like Cottonwood said "If there is uncertainty in the calculation, Tesla should just put all of that uncertainty below 0"
One last piece of information. Tesla did pay for the towing, which is not their normal policy if a car runs out of range.�
Oct 29, 2014
WarpedOne So, you are saying you can not do that now?
Car strikes forward with full power without you demanding it?
News for you: the right pedal is not On/Off switch. It is a 'gradual device' that tells the car how much power you want from it. Press it only a bit and only a bit of power comes out. Press it full and full power comes out. I say magic!�
Oct 29, 2014
basvk Check out this thread in the Dutch part of the forum (with pictures): Accu tot op de bodem leegrijden , that is actually exactly how Tesla implemented it (you see the dashed yellow line come all the way down to 20kW). I'm a bit surprised about what happened to giants2001's car though.�
Oct 29, 2014
scaesare WarpedOne-
I was responding to what happened as decribed by giants2001:
Obviously I understand I can modulate my speed and I know the "pedal on the right is not an on/off switch".
But what that's not what continued to happen despite additional range displayed, as described by the poster.
Please look at context of a conversation (which was even quoted in my response), before the rather snarky reply. Thanks.
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Understood... I've driven my car down to zero once, and indeed that's correct. I did not drive all the way to shutdown, however. Indeed it's giants2001's experience I was commenting on where it shut down "early", apparently based on demand. That's not cool.�
Oct 29, 2014
WarpedOne I'll continue to doubt the description is faithful description of what really happened and what Tesla said happened and what was the real reason and when exactly the car really shut down.
To many times to many details get lost in translation driving one to reach wrong conclusions and making silly demands.
Car shutting down completely because "it cannot do 70mph that is demanded from it" is just plain silly explanation.
How does car know what speed is demanded from it? Cruise control? There is that button to shut CC off ...�
Oct 29, 2014
scaesare Feel free to doubt. If so, please address the original information provided.
In the mean time, please don't condescend the the others of us also discussing it, all the while you are ignoring the premise.�
Oct 29, 2014
bluetinc Has their policy changed? I've heard of multiple people being towed on Tesla's dime for this and have not heard of a policy change. I've even heard this quoted to customers in the stores by sales staff.
Also, can you give a little more info on the details of the shutdown and Tesla's engineering response?
The shutdown doesn't sound like any other I've heard of (Power limit, etc.), or what I've seen driving near 0. Could it be what happened is that under load and low energy a cell in the battery failed, caused the computer to recalculate the amount of energy left in the battery (now instantaneously below 0 and in the shutdown range), and then the system decided that it was time to shut down? That explanation seems like it would fit your description better.
Peter�
Oct 30, 2014
franknesss I think a large part of the confusion is the way range is presented. On the dash, even when the "Rated Range" is 0 that doesn't mean that the battery has 0%. That's because rated range is distance based off of 300 kWh usage. If, for example, you average less than 300kWh since the last charge (extreme example you avg 200kWh) you technically will run the "Rated Range" down to 0, but still have Projected range and battery capacity. This is where I think Tesla can improve, the current "Rated Range" should be replaced with the Projected range function (either 15mi or 30mi avg) and the battery should show a percentage indicator related to the battery's capacity.
So for example sake, (numbers are not accurate) 1% battery capacity can = 1mi or 10mi depending on driving style.�
Oct 30, 2014
jerry33 And if you're driving 70 mph uphill, you won't have even that. When you're cutting it close, keep the Energy screen on and check.�
Oct 30, 2014
dave Is this a typo, or a real story? How fast were you going?
I just tried to do a 248 mile trip on my 252 full charge. Going 65 with no climate, VERY weak acceleration, and driving behind a semi (not too close, but enough that there may have been a difference). Only made it 220 miles. Makes me think something is wrong with my car.�
Oct 30, 2014
David99 What was your energy usage?
I did it several times. 253 miles from home to destination arriving at 0 miles. Kept the average just below 290 Wh/mile. I ended up using 76.5 kWh. The interesting part is that it amounts to exactly 90% of the 85. So I would say 0 miles means 10% battery capacity left. I only did it once, though. The other times I stopped on the way and charged a little. Much healthier for the battery to not go as low and also gave me some safety buffer. You never know. There could be an accident, a closed road, missed a turn, ... lots of things can make the trip longer.�
Oct 30, 2014
jerry33 It's a real story. Speed varied depending upon whether I was going uphill or downhill from about 55 to 65. I didn't use cruise control, nor did I follow a semi.
Note that when I drove the 2004 Prius, the last full year of driving was 69 mpg over 16,000 miles.
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I didn't take a picture from that trip, but here's the one from October first.
�
Oct 30, 2014
andrewket 201 Wh/mile and a good part of it wasn't downhill? I'm impressed. I've hit 250 on a few occasions. 201 is impressive.�
Oct 30, 2014
jerry33 The 201 wasn't really what I was trying to show as that's a one-way--it goes up to about 220-230 by the time I do the other 25 miles. The 252 is the more important number.�
Oct 30, 2014
HankLloydRight I don't think that's the case at all... the algorithm constantly adjusts the remaining "rated range" based on actual battery capacity times some Wh/m constant (believed to be 300 Wh/m or some say 280 Wh/m). So if you're doing 200 Wh/m for say half the battery capacity, the rated range will be far less than "projected", but they both meet at 0 miles, albeit rated range declines faster than projected range. So zero still means zero.. if you're doing 200 Wh/m, you're not going to end up at zero with a huge buffer because you economized the Wh/m for the entire trip.
Having the dash indicate "projected range" is far more dangerous than how it does it now, because if you're tooling along at 200 Wh/m and projected range goes way up, and you hit some rain or worse, stop and go traffic, your projected range is going to plummet and leave you stranded.... whereas the way they do it now, it's much more constant based on the average Wh/m (300 or 280).�
Oct 30, 2014
dave Wow, I've never been able to achieve even a one to one rated mile usage on a highway trip. Granted I've never set the cruise below 65, but even at 65 I was hoping to get the rated miles.
Do you have an S? I've always wondered if the P's just use more energy, even with the same driving behavior.�
Oct 30, 2014
David99 According to Tesla the standard and the P version are exactly the same in terms of energy usage and efficiency. The max power is just different.�
Oct 30, 2014
dave I understand what Tesla says on the matter. Just trying to figure out why I can't get the range that others frequently report.�
Oct 31, 2014
jerry33 FWIW, it took me two years before I achieved my first 60 mpg tank on the 2004 Prius (at the end a 75 mpg tank was common). Some of that was new car break-in. Some was that no one really knew how to drive the Prius efficiently. There were many hypothesis proposed--a number of which were discarded as time went on, and it took a while before everyone accepted how the Prius actually worked. Basically it comes down to checking your tire pressures regularly and practice, practice, practice. Terrain and climate will also have a large effect.
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It also assumes that both are driven exactly the same and have the same tires. I doubt that the same driving style happens much in the real world.�
Oct 31, 2014
franknesss Came across a YouTube video that shows a person driving an extra 3 or so miles after it hits 0.
�
Nov 3, 2014
neandertal So I had my first experience yesterday with running out of range. headed north to Albany SC into a severe headwind with a 40 mile buffer. 200 mile range (60 kW Model S) and 161 miles to go. Usage was average around 341 w/mi due to headwinds average 25 to 30 miles with gusts up to 45 mph. Crappy day for a road trip in the Model S. Did find a few cars to draft for about 50 miles, which got me within 6 miles to go when I now had 0 range. The Charge Now came up on the range (wasn't taking photos as I was quite nervous now) and the yellow bars on the kW side of the speedometer were now around 60 k limiting power. Amazingly, I was able to drive 6 miles beyond zero to the Albany SC.
Not going to do that again. But I can confirm that I drove six miles beyond zero. I drove around 45 to 50 mph for the last ten miles (+4 to -6), very conservatively not pushing the car or letting the accelerator draw hit the yellow bar on the kW scale.
When I pulled in to the SC stall, said a quiet thank you and saw that I had used 54.8 kw of charge on the battery. Don't know what is left behind so you don't brick the 60kW battery, but I had started shutting off running lights and radio (of course, I never used the heat the whole way or defrost while driving). Had done everything to minimize the drain on the battery other than driving.
Still am amazed I made it. Definitely need to plan better and check the weather forecast.�
Nov 3, 2014
WarpedOne 40 miles of buffer may sound plenty but over 160 mile planned trip this is only 25% 'reserve'.
As you found out, that may not be enough.
I recommend at least 30% reserve and/or contingency plan - investigate charging opportunities.�
Nov 3, 2014
Cottonwood Glad that you made it!
Wind is a 4-letter word!!!
When you see the buffer/margin slipping away rapidly, even into a stiff head-wind, slowing down will help conserve your battery. The sooner that you notice that you will be in trouble and can slow down, the better, and the more energy that you will conserve.�
Nov 3, 2014
yobigd20 I have an 85 and barely made it to Albany from Edison. Only charged to 90% 230 miles and arrived with 3. So yea I used 227 miles to go 160 miles. Kinda crappy uphill. I was going like 75 to 80 though. Next time I'll max range charge it.�
Nov 3, 2014
Cottonwood Slowing from 75 to 70 over 160 miles will only cost you about 10 minutes, and gain you about 25 rated miles over that distance. Charging from 90% to 100% will probably take more than 20 minutes, and will gain you about 25 rated miles. Slowing down a little is usually better than 100% charging on a Supercharger.�
Nov 3, 2014
yobigd20 Ooh but driving that slow just really huuurrrts and is painful for me to crawl. (Seriously I have a speed issue).�
Nov 3, 2014
HankLloydRight What is the optimal speed to drive to absolute maximize range? Wasn't there a graph from Tesla that showed that 45mph to 55mph was the peak of the efficiency curve?
Glad you made it to the Albany SC... it's not exactly right off the highway, so it's lucky it didn't die maneuvering around in that parking lot or those access roads. If only there was a way to hit a button to tell the battery "but I only need to go 400 more yards to charge!! I promise!".�
Nov 3, 2014
David99 It's on their blog somewhere. I think it's around 25-30 mph.
Part of it is the motor optimized for a certain speed but also the battery. The slower it is discharged, the more energy can be used because the internal losses are smaller at a lower rate.�
Nov 4, 2014
jvonbokel Here's the blog post. The absolute ideal is probably around 21-22mph.
Model S Efficiency and Range | Blog | Tesla Motors
I can confirm this from personal experience. When I completed the 400mi challenge, I used 77.9kWh and still had 3 rated miles remaining, which is a few kWh more than SarahsDad was able to eek out going all the way to zero rated miles. Of course, I had to average 194.4 Wh/mi (24.31mph) to do it.
Full gallery here.�
Nov 4, 2014
neandertal Given that the head wind was killing the drive, I figured that drafting at 65 mp would put less resistance on the car and get me faster to the SC. I was trying to get to western Mass that morning, so I wasn't really planning to drive @ 50 mph all the way. But, I would have been really late if I needed a tow to the SC :cursing:. Overall a very illuminating exercise and one I don't plan on repeating. Now I will wait to do this trip again until the Newburgh/New Paltz SC comes along.�
Nov 4, 2014
franknesss This sort of makes me wonder why Tesla just doesn't go with a battery percentage to display how much is capacity is left, and use the calculated projected range to show range. This way the battery percentage will match the projected range, based off your driving style.
jvon, were you able to get any picture of the Projected Range? (based off 30miles) I'm curious to the discrepancy between the projected range and rated range.
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Nov 4, 2014
jvonbokel You know, this sounds like something I'd do, but I just looked and apparently I didn't. I know I forgot to take shots of the trip meter for the first 100mi, so I guess I shouldn't be surprised I forgot to record some (any) projected range data.I wish they'd just include the projected range on the instrument cluster version of the energy graph. They could make it stationary in the space where there's more room (in the 0-300 Wh/mi area), and just draw an arrow that points to the avg line.
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Nov 4, 2014
David99 They kind of do. The energy usage graph does that. It allows you to use your average from the last 5, 15 & 30 miles to calculate your projected range. It actually is pretty accurate. I use it when I have bad conditions (head wind or rain) to see how far I will be able to go.�
Nov 5, 2014
jvonbokel In very early versions of the firmware, they allowed you to chose "Rated Range" or "Projected Range" for the number shown in the center of the speedometer. I'm not sure why they removed that option.�
Nov 5, 2014
franknesss I would like to have the projected range displayed on the dash instead of the screen though. Unfortunately, it seems like Tesla removed that option.
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Nov 18, 2014
wycolo Zero = Zero: Winter Cautions
Here is a pretty good test of going past zero on 6.0(1.67.28) with an S85 (mfr 07Dec2012). No headwind on slight but steady uphill grade at 22*F. 40 miles into the 135 mile trip I realised that I had set the charge limit 20 shy of what I intended (a 'winter' supplement) thanks in part to that Quija 'do you feel lucky today' charging scale. Thus I drove gently but had to deal with more packed snow than I had anticipated. Below 10 miles I really sensed failure so drove on the shoulder below 30mph. The last few miles were at 20-25 mph. Hitting 0 raised no messages so I pressed on gently hoping to reach the village. Within 1/2 mile message said Charge Now followed almost immediately by Car Shutting Down. I stopped and backed 60 feet into a wide side road which turned out to be the entrance to a concrete/gravel plant and put it into TOW MODE. Hooked up a rope to the trailer hitch and a company pickup pulled me up to one of the cables used for block heating. 115v 12A = happiness, or was it??
THE WINTER PART
Watching the charge screen promise "4 miles per hour" charge rate for over an hour without any tick up to even 1 mile brought on the realisation that battery heating is included in that figure so I may not be getting any additional battery charge at all!! No way to tell. After 2 hours called Service Center who opened with "we've been waiting for your call!" They know when one of their cars hits ZERO and can see it on the map (just 4 miles from Silverthorne SpC). They saw that my charge was up to 4.5%, oh it just ticked up to 4.7, and roughly might be equivalent to as many as 8 miles or so, but give it at least another hour. BTW you were down to 12.1v if you had hit 12.0 it would have been instant death!! Whew.
An hour later still no tick up above Zero. I did not think to dig out battery energy info- is it possible to read out % charge on the car's screens?
I charged for 4 3/4 hours at 115v 12A with the screen still showing 0. I had disconnected and turned the car around to maximize solar gain and then resumed charging but the 0 did not change. So I threw in the towel since it was down to 17*F and for all I knew I was achieving no net charging. Drove the 4 miles to the SpC with no miles, zero or otherwise, showing on the speedo. In its place was a red notice to CHARGE SOON or some such. Backed up into thick snow to a bad charger! The second try succeeded. Charge started at 0 but took a long time to jump to 1. Did not begin at a full 120kw but maybe half that rate. I failed to record data choosing to run for food before closing time.
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Nov 18, 2014
apacheguy You can have a web server read percent SOC and print it out to the touchscreen. That's what I do so I don't have to rely on the in car battery gauge.
Thats weird that 4% SOC wasn't even registering a rated mile. The way you make it seem, when you get down to 0 rated miles, the car quickly shut down. But when you go the other way (charging back up), the 0% should have been lined up with the 0 miles. I wonder if the SvC was including bricking protection?�
Nov 18, 2014
yobigd20 I never thought about using the REST API and hosting a private little app in the cloud to view detailed stats via touchscreen. Nice...fairly simple to do too.�
Nov 19, 2014
AndreyATC I wonder if TM can simply integrate your destination to allow extra few miles below 0
The car knows it is about to approach supercharger or home (previously charged locations).
Why not just let few more miles to reach charging station, with some tolerance of 5-10 mile max
These batteries can probably survive extra percent of discharge�
Nov 19, 2014
David99 Because there is a good chance you can damage the battery permanently. In this very discussion we have seen that some people don't understand how bad it is to run the battery down to 0 especially when drawing a lot of power from it while doing so. People will just assume that the car will allow them to get to the next Supercharger, no matter what and floor it. The reason why Tesla is able to give us a very comprehensive warranty on the battery is because they protect it from being damaged.
As many people have reported, you can go passed 0 and you can go quite a bit when you take it easy on the accelerator. I have been able to go 9 miles passed 0 once. I saw it coming, I slowed down and drove carefully. The car allowed me to go further. Why? Because it doesn't shut down at 0, it shuts down when the battery level reaches a critical level. The easier you are on the battery, the further you can go.�
Nov 19, 2014
AndreyATC David,
part of the feature could be limit of 30-40kw power
kind of like limp mode�
Nov 20, 2014
wycolo I babied the throttle even before the last 36 mile leg. But that leg, Kremmling on the Colorado River (6600 ft elevation) to Silverthorne (8600 ft), is upstream all the way into town. With the rolling hills it is easy to overlook the significant net climb going south.
I wonder if those who have reported being able to go well past ZERO were not in fact going down a gentle descent that somehow seemed to be level.
The way this played out for me was that I was a captive of Service Center directive; only they could read my %battery thus determine when I could best make a slooow dash the final miles to the SpC. Appears to be the intent of the new software upgrade and actually a good thing since SC stressed that a decent extra margin be achieved before venturing out on the roads. Left to my own devices were I able to continuously monitor %battery, I might have cut it dangerously close. Nonetheless it would have been neat to be able to monitor %battery from in the car.
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Nov 20, 2014
David99 It would make a lot of sense, but I believe Tesla specifically stayed away from any feature that would be perceived as a weakness or shortcoming of the battery or car. Tesla sells performance and top comfort.
I would hope in the future Tesla has enough real world data (including elevation changes) from all roads and can predict how much energy you will need to reach your destination. It could give you a recommended speed right from the start and on every section of your trip to make sure you will arrive.
At the moment almost every modern navigation app (Waze, Google maps, TomTom) has real world data from every road at any given time of the day and can make a pretty good estimate on how long it will take. Some even use real time traffic. What's missing is the energy usage for EVs. Once there is enough data from is collected from all the Teslas on the road, this will be part of the navigation system. That's the only way to go. The current calculation based on 'rated range' is really poor and inaccurate.�
Nov 20, 2014
C.r. Moorehead I can tell you that I had a driver contact me from Plugshare - He showed up to my house with zero on the dash and said he had been driving 2 miles approx after zero - 2 things need to be discussed. First off - It is the WORST thing that you can do to the battery to drain it completely. Second - why would you want to chance it that close anyway? Is it people without Telsa's asking these questions? Are you the type of person to go 4500 miles before you changed your oil? My rule of thumb is "Pay now - or Pay LATER" I used to laugh at people driving high end mercedes and Range rovers - too cheap to change the oil and then the first to complain at a bill of 10k for a new replacement motor! LMAO! Ignorant idioits! Don't be dumb - charge your car - keep it 80% ish and enjoy life!�
Nov 22, 2014
wycolo For one thing 9000 mile oil/filter changes are routine today. Further, stuff will happen, so trying to understand the limits presented by software upgrades will benefit users.
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Nov 22, 2014
jerry33 The BMS will shut the car down before you drain it completely--even if you've driven a bit past zero. The trick when driving is to plan where you're going to stop and have a couple of alternates just in case--including some that are well before the destination in case "stuff happens". By planning, that doesn't mean finding a place that's 250 miles away to charge. Every 150 miles is what you should shoot for, and 220 miles is about the maximum planning distance in an 85 in good terrain and weather. Especially the first time going to a particular destination, being conservative is a virtue. Once you've gone to a destination once and know how the car will use energy, then you just have to check the weather, wind speed and direction.�
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