Dec 22, 2012
DaveVa I had V4.0 software an went to friends house. Arrived with 145 miles rated range. When leaving 16 hours later range had dropped to 102 miles rated range. Car was uncovered in the driveway overnight with cold temperatures and high winds. I have sleep mode enabled - so this is not the normal "vampire load" issue with the displays. It's just likely what the car needed to do to keep the batteries warm - both regen and power were limited in the morning.
I'm all for Tesla maximizing care of the battery pack, however it is important to communicate expected behavior. I could have plugged in to a 120v outlet at my destination, but didn't since 145 miles range was plenty to get home (100 was just enough).
Have others seen similar behavior? Will v4.1 be different?�
Dec 22, 2012
jerry33 I believe you're the first to report this (at least in the Model S), but it's not at all surprising. It's unlikely 4.1 will be different.
One of the reasons the Bismarck was sunk was because they didn't fill up when they had a chance and that narrowed their route selection. When leaving Europe for the North Atlantic they had a chance to fill up but the Captain decided that 80% of a tank was enough for their planned course. Tesla's plug it in every night has that kind of meaning.�
Dec 22, 2012
Al Sherman Interesting. That's also number 1 on the list of the three things in aviation that you can never get back: Fuel you left in the truck."�
Dec 22, 2012
kendallpb I think this is good anyway, because you never know what may happen. Oh, I need to run an errand. Oh, I wasn't paying attention and floored it. Oh, I'm giving my friend a joy ride before we leave. Oh, this road's closed and I have to go 30 miles out of my way. Etc. If you can plug in, IMHO, do.
But I'm quite surprised at that much of a drop, in so short a time, especially with "sleep mode" enabled!�
Dec 22, 2012
RDoc So what happens if you leave it at an airport not plugged in for a week and a half in the winter with temps in the teens overnight and 30's in the day? Certainly plugging in whenever possible is a very good policy, but that's not going to be possible in many cases.
I agree, Tesla really does need to tell its customers what the car's behavior will be in different situations.�
Dec 22, 2012
yobigd20 take a different car. lol.�
Dec 22, 2012
kcveins This will be my ONLY car....�
Dec 22, 2012
montgom626 Always plug in. Good advice.�
Dec 22, 2012
jerry33 Given what the airports charge for parking these days:
1. Park at a third party site that has plug-in facilities--even if it's only 110V (Most places where it gets that cold will have plugs for block heaters.) You might have to call around and ask.
2. Take a taxi or airport limo.�
Dec 22, 2012
highfalutintodd +1
This thread is easily the one that's making me the most concerned about my pending Model S purchase. I don't travel all the time, but when I do I can be gone for days at a time and usually get back late at night. While Nashville isn't exactly the Arctic Circle, it can get damn cold in the winter. The last thing I want to find is a drained battery 20 miles from home in the middle of a cold night.
According to the Tesla Model S "facts" page (and something I've been taking at face value):
- - - Updated - - -
How cold are we talking here?�
Dec 22, 2012
stopcrazypp Sounds to me like cold soak. A cold battery means that it has to get up to operating temperatures before regen is enabled again. There may also be voltage sag which makes capacity seem lower (will recover at optimal temperature). Did you see the range return after driving a while?
I remember the Roadster does turn on the A/C to in hot temperatures even when unplugged, but it does not do the same with the heater in cold temperatures. So it's possible for the battery to be cold soaked and then regen will be disabled (because charging the battery in the cold can damage it). Once you plug it in, the battery heater will heat up the battery before it starts charging. If driving unplugged, it will use up some range to heat the battery (see second link, it's reported as 10km/6 miles of range for the Roadster).
http://www.teslamotorsclub.com/archive/index.php/t-6977.html
http://www.teslamotorsclub.com/archive/index.php/t-7467.html
I don't know if this has changed in the Model S. Without a battery temperature gauge like in the Roadster, it's hard to tell.�
Dec 22, 2012
MikeK I reported the same thing in the Vampire Load thread the other day. I parked the car with 106 miles of range, and in the morning it was 72 miles, with limited acceleration and regen.
I'm hoping that the car will be well-behaved during the week I am leaving it parked at a friend's apartment complex while I'm traveling. There was no outlet available to leave it plugged in. It's supposed to be in the 60's during the day and the 40's at night, and it will be under cover. I am assuming that the car has some kind of threshold below which it will not continue to use pack energy to keep the pack warm.
I agree that such a large drop in range when parked overnight is quite a surprise. I had to arrange for an unexpected charging opportunity.�
Dec 23, 2012
johndoe74 This is one of my biggest worries about this car. When a Roadster's battery bricked without plugged in this summer, Tesla came out and reassured the Model S can be safely unplugged for an extended period of time. If it takes 20+ miles of energy to warm the battery for 12 hours, then I don't see how one can really leave this car unplugged for more than 3 days. And suppose the battery is depleted and can't no longer warm the battery, won't this cause the same bricking problem faced by the Roadster?�
Dec 23, 2012
Johan The important question here is if the car has actually consumed all those "miles" (kWh) during the cold night OR if range just seems depleted at first due to the battery being cold and the battery system due to this reads a lower voltage, maybe also changes in impedance etc. which makes it think that the SOC is lower than it is/will be read once the battery comes up to proper operating temperature.�
Dec 23, 2012
Todd Burch That would imply that the car was using about 800 continuous watts to keep the batteries in acceptable range over the 16 hour period. That would be A LOT given that it hasn't been THAT cold in VA the last few days. My guess this is just due to low battery temp and it would've gone up as the battery warmed, as others have said.
Tesla should be able to compensate for the reading by adjusting the range figure when the battery is cold.�
Dec 23, 2012
Johan Might be easier said than done. What if the SOC is actually low AND the battery is cold. Maybe it gives a similar reading. I.e. perhaps the car can't know for sure until the battery is worm?�
Dec 23, 2012
Todd Burch I'm not a battery expert, but you may be able to calculate an approximate voltage sag based on temperature and translate that into a range compensation. I'm not looking for a pefect compensation, but something's better than nothing.�
Dec 23, 2012
donauker In 3 winters and 48,000 miles on our Roadster they never had this problem with its battery pack.�
Dec 23, 2012
RDoc I've never seen a parking facility anywhere in the New Hampshire or Massachusetts area with a block heater plug and we get temperatures like that almost every winter.
Certainly taking a ICE vehicle is a solution, but the OP was WRT Tesla telling owners what to expect. If the car can't be left in cold temperatures for several days without being plugged in, fine, but Tesla should make that very clear.�
Dec 23, 2012
MikeK Now that is a really interesting question. I babied the car a bit that day because I had to make it to my friend's house where I would be able to charge. I remember noticing when I plugged the car in that it had 55 miles of range showing been though if the morning estimate were correct it would have had 36. So, perhaps the 34 mile indicated drop was a combination of a little bit of normal overnight charge loss and also a change in the estimate due to a cold pack.
I will certainly post an update when I return from my trip, and I hope that the update will not include the words "brick", "flatbed", or "AAA"!�
Dec 23, 2012
jerry33 My experience is in Canada and the Western U.S. Bad assumption on my part that the East would be similar for similar conditions.
Agreed. First we need to make sure it's just not a temperature inducted artifact on the display.�
Dec 23, 2012
Johan MikeK: I wish you luck with this and Merry Christmas!�
Dec 23, 2012
kendallpb If nothing else, some kind of warning like "Battery cold--range estimate may be lower than actual range; range estimate will correct itself as the car warms up" or something, so folks know not to panic.
If this is the issue, I mean.�
Dec 23, 2012
DaveVa After 20 or so miles my rated range gained about 15 miles (80 to 95). I don't know if it would have gained more than that, because I was able to plug in at that point.�
Dec 23, 2012
dennis Correct me if I am wrong, but doesn't the Model S only initiate charging when you plug it in and terminate charging once the battery has reached the requested capacity? If you leave the car plugged in and go away for an extended period, what will cause the car to re-initiate charging to replenish the charge lost to conditioning the battery?�
Dec 23, 2012
MikeK I've been told that the car will use "shore power" to keep itself topped up and to keep the battery within operating temporary ranges.�
Dec 23, 2012
Larry Chanin Hi Dave,
I had a similar experience.
Two nights ago I parked my Model S overnight at a hotel without plugging in. It was cold for Florida, it dipped into the high 40's. I had 160 miles of rated range when I parked it and the next morning it displayed 130 miles. At the time I had the impression that regeneration was greatly reduced. That morning we drove just a few miles and then I went to a friend's home nearby to charge at a NEMA 14-50 outlet for an hour or so.
I didn't closely study the charging process, but I do recall noticing the range was now 140 miles, then just a short time later it was about 165 miles. I didn't check my watch during this process, but my impression was there wasn't sufficient time to add that much range at typical charging rates. I of course don't know, but I believe perhaps the heating of the battery during charging caused the car to recalculate range higher rather than charging actually adding that much more energy.
I had version 4.0 of the software at the time and I had the "KEEP DISPLAYS POWERD" feature in the OFF position.
I reported this behavior to our local service manager and he said he was opening up an engineering case.
Larry�
Dec 23, 2012
PRJIM My Model S is parked in the dead of winter at the Buffalo-Niagara Airport for the next 7 days. Fingers crossed.�
Dec 23, 2012
jerry33 My understanding is that it will occasionally restart the charge to keep the battery topped up (assuming standard charge). I think it's only once a day or some similar interval.�
Dec 23, 2012
Jaff Dave, unfortunately you have learned the hard way...first rule of cold weather "EVing" is "if you can plug in, even if it's only to keep your pack warm, do it".
I drive my Roadster all year round...my trip house to office is about 3 kms...I installed a 110 volt plug behind my office for the express purpose of keeping my pack warm...only takes a minute to plug in, so, if you can plug in, there's no reason not to do it...�
Dec 23, 2012
Larry Chanin Unless there is something specifically amiss with my car, topping off occurs much more frequently than daily. I'm guessing its probably at least hourly.
Larry�
Dec 23, 2012
dennis I don't believe that is happening with my Model S. Since 4.X has not yet downloaded, I am still losing 10 miles/day. My charging usually completes around midnight, and when I unplug the next day, the indicated range varies, but is always less than that of a standard charge. And the later I unplug, the less range I have. That is what prompted my query.�
Dec 23, 2012
PRJIM If the vehicle is plugged in for 5 days the amount of usable range is reduced by 30-40 miles. If you were to check on the range after an overnight charge, the range should be- I am guessing- between 220-240 miles. The longevity of the battery is tied to the SOC. The optimal usable SOC is 40-60%. This is probably the reason your car is bleeding miles.�
Dec 23, 2012
montgom626 I am unclear why a plugged in MS would lose charge?�
Dec 23, 2012
mdh this topic is rather concerning... I hope someone gets a response from TM.�
Dec 23, 2012
dennis I believe my car is bleeding 10 miles per day because it is keeping the displays powered since I don't have 4.X. That said, assuming a standard charge (240 miles), at what point of bleed-off should I expect the system to re-initiate charging of the battery, assuming the car has been plugged in continuously because I am away on vacation?�
Dec 23, 2012
montgom626 Have we gone off topic??
Have we gone off topic??
The title of the thread is
Large Drop in Charge When Parked Unplugged in the Cold
Now we have moved to
Large Drop in Charge When Parked plugged in the Cold??????????
�
Dec 23, 2012
dennis I don't think we are off topic. The question I posed was whether keeping the car plugged in would in fact keep the battery charged, since I haven't seen that happen with my Model S.�
Dec 23, 2012
PRJIM I believe the car will try to keep the SOC in the 60% range. This would be the equivalent of "storage mode" that is present in the Roadster. I have 4.0 and my vehicle still loses at least 7 miles a day when plugged in. Are you on 1.15.4?�
Dec 23, 2012
dennis I am on 1.15.14. My car was delivered on 10/30, and neither the Menlo Park service manager nor Ownership have been able to determine why I haven't received the 4.0 upgrade.
Do you have any guess on what 60% SOC represents in terms of "ideal" range?�
Dec 23, 2012
dsm363 Around 180 miles I think (300 ideal miles with 265 rated miles). Hope you get the update soon.�
Dec 23, 2012
montgom626
Okay, but the tone of the posts now seem to imply that when plugged in the MS loses charge. I think that has got me a bit confused. I can understand why when unplugged it would lose charge, but I have no idea why it would lose charge when plugged in. So why are folks posting that the MS loses charge when plugged in?�
Dec 23, 2012
dennis Thanks, I did not realize it was linear. :wink:
- - - Updated - - -
It loses charge because of conditioning the battery when cold and keeping various electronics running. Apparently, once a charge is complete it will not "top off" until the State of Charge has dropped enough so that repeated charging will not reduce the life of the battery.�
Dec 23, 2012
Larry Chanin According to Tesla charging in Standard mode does not reduce the life of the battery. Charging in Range mode does. I believe that in Standard mode the car will repeatedly top off to achieve 240 miles. So far each morning the range of my car has remained between 238 and 241 miles when charging in Standard mode. If the frequency of topping off were say daily I would expect a much larger variation in the range in the morning.
Larry�
Dec 23, 2012
PRJIM I am not sure if this is true. If I do not use the car for a few days, the range will drop to the low 200's- while plugged in. Tesla also said that charging in standard mode does not reduce the life of the battery on the Roadster yet they implemented "storage" mode. When a Roadster is put in storage mode, the vehicle bleeds miles until it reaches a particular SOC.�
Dec 24, 2012
montgom626 That makes perfect sense.�
Dec 24, 2012
mknox Anyone have their charging circuit independently metered with something like a TED 5000? Reviewing those logs would definitively show when the car is drawing shore power and when it's not.�
Dec 24, 2012
dennis I am about 10 days away from having circuit monitoring completed for my house. If no one has verified this before then, I will definitely monitor and publish the results.�
Dec 24, 2012
montgom626 Please publish...................�
Dec 24, 2012
Larry Chanin From the Model S Owners Manual (also displayed when selecting the charging mode) :
Dennis posted:
Tesla is saying that repeated charging in Standard mode maximizes battery life so it does not necessarily follow that topping off would have an unduly negative effect on battery life since it is only charging to 90% of its full capacity.
Larry�
Dec 24, 2012
dennis It seems that we need to establish two things:
1) When the car remains plugged in after completing a Standard charge, at what point (State of Charge?, timer?) does the Model S re-initiate charging to bring the battery back to "full"?
2) Is that the correct/intended behavior?
Several answers to 1) have been postulated, including hourly, daily, and at a particular SOC. AFAIK, no one has yet verified the actual behavior nor found a statement of the intended behavior in any Tesla documentation.�
Dec 24, 2012
RDoc While interesting, shouldn't all that be in a different thread? This thread is about what happens if a Tesla is left in the cold for an extended period of time when not plugged in (note the thread title).�
Dec 24, 2012
dennis While the mods should feel free to move it to a new thread, the reason I posted it here is that I believe that the car may continue to lose charge even when plugged in.�
Dec 24, 2012
cinergi I've been monitoring mine since I'm away for a week... the lowest I saw rated range get to, so far, is 231. The next time I checked it (many hours later) it was 237. I'll continue to watch over the course of the week...
(Software version 4.1)�
Dec 24, 2012
dennis Since you are away and monitoring, does that mean you are beta testing the Remote App? If so, does that make any difference to the charging regime? Or do you have a human that is checking range for you? :biggrin:�
Dec 24, 2012
MikeK Plugged in, or unplugged?�
Dec 24, 2012
tezco Stevezzzz does:
(Feel free to move to Vampire Load if appropriate.)�
Dec 24, 2012
PRJIM I had a friend of mine pick mine up from the airport as I did not want to risk a stalled vehicle when I came back into town from vacation. He reported 143 ideal miles at the airport. When I left the vehicle 40 or so hours ago, it had a range of 217 miles.�
Dec 24, 2012
tezco How cold was it?�
Dec 25, 2012
jkirkebo This is the one thing that concerns me about the Model S. I will frequently use it to get to our cabin in the mountains, where there is no grid power. Only solar, which is too small to charge the S, and a Honda EU6500iS generator which I want to run as little as possible.
I will probably mostly arrive with 50-60% SOC remaining and might stay for up to 5 days in temperatures as low as -20degF in winter. I have taken the Leaf several times and it uses very little power in that scenario. If the battery gets down to -4degF or so it will use the 300W battery heater to heat it to around 7degF. At this temperature it is nearly impossible to charge the Leaf (charging power was down to ~500W at ~83% SOC) but driving was no problem at all. No regen for a while of course.
If the Model S attempts to keep the battery at an optimal driving temperature all the time I will have to run the generator a lot every day. That I seriously want to avoid. What I need the car to do is get to a "deep sleep" state where most electronics are powered off (I don't car if the screens take 2 minutes to boot up) and the battery temperature management only keeps the battery as warm as it needs to be to avoid damage. In the event that I suddenly have to drive the car I don't care if I have no regen and the power is limited to 50kW.
When I want to leave, after say 5 days, I'd ideally power up the generator for an hour or so, then waking up the car and letting it heat up the cabin and battery to optimum driving temperature (preferably with full regen as it is an hour of downhill driving first). The generator can deliver [email�protected] (5.5kW) continously which should be more than enough.
So here's hoping for a future "deep sleep/storage mode" software feature before I have to configure my car. I guess quite a few others also would like this fetaure.�
Dec 25, 2012
dsm363 It sounds like this isn't possible from what you wrote but are you able to trickle charge over that time period since you are there for so long to get a full standard charge with your solar system? (Similar to 110V outlet in US)
- - - Updated - - -
I changed the title to make it relevant to both plugged and unplugged in the cold situations since both seem to be a factor.�
Dec 25, 2012
jkirkebo Nope. While the inverter surely would have no problems delivering for example [email�protected] to the Model S, the cabin batteries are not up to the task for any usable length of time. The array is only 900W and we do get very little sun in the winter. The battery bank has ~8kWh usable when full and is not always full when we get there. The 8kWh is not always enough even to run the cabin systems for the duration of our stay, hence the generator. If the battery bank get too low I can put [email�protected] into the battery bank from the generator (going through an Outback inverter).
In the summer we can stay mostly indefinately as daily solar production usually matches consumption, but there still aren't much left over to charge the car.
Now, if I had four of those 7000Ah LiFePO4 cells and a 5kW solar array on a dual-axis tracker I could do some useful charging
�
Dec 25, 2012
montgom626 Thanks, the questions I now have are
1) At what SOC, while plugged in, does the MS have to drop to be charged?
2) When the charging resumes due to lowered SOC (see #1) how high does it take the SOC?�
Dec 25, 2012
MikeK 70 miles in two days! :scared: I may be walking home...
I second @tezco's question: how cold was it?�
Dec 25, 2012
mdh I guess 4.0 SW sleep mode is not cutting it?�
Dec 25, 2012
wycolo > 70 miles in two days! [MikeK]
My guess is that maybe the cabin heater was left on, albeit at a low setting. Small button on center screen bottom turns this completely OFF. This should be clearer, maybe show an estimate of available hours at this setting (without draining batt too much??).
--�
Dec 25, 2012
MikeK Cabin heat shuts off when the car shuts off.�
Dec 25, 2012
pbrulott This thread is very interesting while concerning
It brings a fundamental question on EV: Outisde of the pure driving ecomonies (comparing wh/mi and mpge and ICE mpg), are we now saying that there is a signifiquant energy requirement 365 days a year to keep the pack warm and some functions alive? What is that cost?
And could I ask somebody that has a deep understanding of the matter (either plugged or unpugged with use case - really cold below -10F, cold 32F to -10F and avove 32F ) to summarize the issues and behavior encountered.
agree with jkirkebo, TMS needs a deep sleep mode and better cold management functions
PB�
Dec 25, 2012
JRP3 Part of the problem is the batteries don't care if they get really cold, as long as they are not being used, but sub freezing temps can affect them during charge and discharge. So theoretically Tesla could disable any temperature conditioning while parked for long periods IF the pack could be warmed back up before use. Ideally you'd be able to put the car to sleep and have it wake up and warm the pack a few hours before you need to drive it. There is a risk that if you returned sooner than expected and the pack had not warmed enough the car would not drive to protect the pack.�
Dec 25, 2012
jomo25 I'm still wondering how Cinergi is remotely monitoring.
And living in PHX, I'm more worried about the other end of the temp spectrum. What happens to the battery and SoC while sitting in ambient temps of 115 plus. Surface temps often can reach 150+ in the summer.�
Dec 25, 2012
Raven Add me to the long list....What temps?
My garage, although insulated, is not heated and is currently 33*F. External temps are currently a balmy -9*F with a high of +1*F. I'm concerned these batteries are far too cold blooded for me to use the car. I mean, will I need a 240v just to keep up with battery maintenance drain? I don't drive much so 120v is all I need. I planned from the beginning that I'd have to leave it plugged in to keep the pack warm, but if it's losing that much range a 120 will not keep up. Possibly the stated range is simply for a cold pack, not necessarily "lost range"? Warm the car through other means and watch range increase?�
Dec 25, 2012
wycolo 'Shuts off' = what? Do you mean locked? How do you know there is NO cabin heat or fan? My car is plugged in & charging. Maybe that is the difference. 117v 15A but how much is going to cabin heater?
So in the morning you could turn car ON with cabin set to 68 and after an hour it would be warmed up for your commute(?). Need an elf to hide in car after I lock it to supply hourly reports. :smile:
--�
Dec 25, 2012
dsm363 I think you'll want a 240V anyway if that is possible. In such extreme climates, having the ability to draw more power would be helpful. Plus if you ever go on a big trip, the recharge time on a 120V with your pack is 60 hours. 120V is really only a limp-by kind of charging. It works but is very limited.�
Dec 25, 2012
Raven My "commute" is 4 miles and that's only on days I decide to go in. 120 is more than adequate, unless 33* causes a dramatic draw that a 120 cannot keep pace with. Knowing temps and times would be helpful. Having guidance from Tesla would be even more helpful.�
Dec 25, 2012
dsm363 Nice commute. You'll probably be ok then but more information from Tesla would be helpful.�
Dec 25, 2012
highfalutintodd Sounds like Tesla either needs to open a couple of offices in MUCH colder climates than their Northern California HQ....... OR Elon and his family need to start taking some driving vacations to Alaska. ;-)�
Dec 25, 2012
montgom626 I am waiting for my MS, so I can only tell you what I have learned driving a Volt 2012. On 120 v, if I preheat the cabin, the car preheats for 10 minutes, then stops the preheat (AKA remote start in Volt speak). Heating takes a lot of power. It takes another 20 minutes on 120 v to return to original SOC (full battery).
I assume the MS is no different. 120V is not enough to heat the cabin and keep up with the power drain from the battery required to do the heating at 120V 12 amp draw. NEMA 14-50 would probably be fine with the MS (just a wild guess) and heat the cabin without draining the battery. The 120V supplements/augments the power used by the battery to preheat the cabin.�
Dec 25, 2012
Larry Chanin As I have stated earlier, I don't agree with Dennis' assessment that frequent topping off is avoided to preserve battery life.
Until someone camps out in their garage and actually monitors the topping off process, we won't have good information on item 1 (Ben's remote application probably will do the trick), but we do know the answer to item 2.
In Standard mode the car charges to 90% state of charge. In Range mode it charges to 100% state of charge.
Larry�
Dec 25, 2012
JRP3 Depending on what heat level you set it at the heater could draw maybe 3-4kW while a 120V outlet can provide 1.5kW.�
Dec 25, 2012
djp I second the suggestion to go with a NEMA 14-50. Even discounting the heating load, charging at 120V is inefficient compared to 240V. Tom Saxton did a great comparison of charging the Roadster at different voltages and currents and found 120V/12A uses 55% more power than 240V/40A. Results are probably similar for the Model S.
Tesla Roadster Charging Rates and Efficiency - Tom Saxton's Blog
Odd that I don't notice the Ideal Range changing on my Roadster as the battery temperature changes. I'm guessing it's a firmware issue with the Model S and not a loss of true range.�
Dec 25, 2012
Raven So can one assume that a 120v is sufficient to maintain the battery temp within operating range but insufficient at maintaining range charge while preheating cabin? Two separate issues. The latter I don't care as much about. My concern is the battery drawing charge in excess of what a 120v can provide, thus causing the battery to deplete while trying to maintain itself. It would be pretty sad if it can't at least keep up. Electric car charging is virtually non-existent around here so 120v is all I'll have when visiting family(unless I install 240v for them)�
Dec 25, 2012
Doug_G I charged then parked unplugged last night at about 10 pm. It was showing 380 km rated range (IIRC my last full Standard mode charge came in at 389 km). Today at 1 pm it shows 364 km, a drop of 16 km (10 miles). Sleep mode was enabled, and garage was at about 5 degrees C.
I decided to try plugging into 110V. While fiddling with it the door was open, and so the HVAC was running, and it dropped to 362. We'll see what 110V does. Since it needs a little charge maybe it'll warm the pack up a bit. I'll be driving it in a couple of hours.�
Dec 25, 2012
dsm363 Would installing a NEMA 14-50 be really expensive in your garage? You wouldn't need it for your daily driving but much better to have 40A at home to charge when you need it that have to wait 1-3 days for a full charge depending on how big a trip you took. If the overhead in cold weather is significant, the 120 outlet will drop your charge rate even more. Since you are getting the 85 kWh pack it is worth exploring since the charge cable comes with the car. Only expense is installing the outlet.�
Dec 25, 2012
Raven That's great news. I'm wondering if the others had different "sleep" settings. I'm guessing it would be pretty simple to program a range preserving/load shedding feature for abnormally hot or cold temps. If it already has it then maybe it needs tweaking.�
Dec 25, 2012
kendallpb Folks report the initial estimate in cold weather goes up--it's inaccurate due to the cold--so I'm more curious what he saw after the car had warmed up (and/or after it got home)...allowing for the drain from actually driving, I mean.
(I presume "143 ideal miles" and "range of 217 miles" were both ideal.)�
Dec 25, 2012
Raven No, the CB panel is on the opposite side of the garage wall so it would be very simple to do myself. I'll probably do it, it just never seemed necessary for how little we drive.�
Dec 25, 2012
Larry Chanin Currently there is only one sleep setting on version 4.0 or 4.1. Displays are set to either power off or not.
Larry�
Dec 25, 2012
surfingslovak Interesting thread. The range loss mentioned earlier does not seem consistent with the energy needed to condition the battery pack. If I read it right, and the OP saw about 40 miles range loss, this would imply that at least 12% SOC or 10 kWh have gone missing.
Based on some prior work on MNL and 0.8 J/g/Kspecific heat for lithium-ion batteries, I calculated that much less energy would be needed to raise pack temperature by 30 degrees from ambient. It would then take about 3 hours to dissipate this heat energy through radiation from the metal battery case. Since only about 1.5 kWh are needed to raise the temperature by 30 degrees, even if this cycle was repeated four times in a 16-hour interval, the total loss of usable energy stored in the pack would be approx. 6 kWh or 7%.
All of this assumes that the battery was conditioned fairly aggressively from the energy stored therein, which probably is not the case. It's much more likely that the battery is simply kept from freezing while in storage, and there is an option to condition it closer to room temperature before driving away. Admittedly, I have little experience with the Model S, but I would have to assume that an instrument error or a software bug were the most likely culprit here.
That said, I believe that it would be very desirable for Tesla to make battery pack temperature and the estimated usable kWh figure available to the driver. It would take a lot of the guesswork out of similar discussions.�
Dec 25, 2012
cinergi Plugged in. Presently down to 231 ...�
Dec 25, 2012
MikeK Sorry, "shuts off" = car is parked and locked. I don't know for a fact that there's no cabin heat when the car is parked this way, but I do know that it was plenty chilly in my car when I got in after it was unplugged overnight last week, and it has been plenty warm when I've gotten in after it has been unplugged during the sunny daytime at my office. So, from this I infer that it is not conditioning the cabin while it is parked, at least when unplugged.
It may be the case that the cabin is conditioned when the car is plugged in. I hope not, actually. That a fair amount of wasted energy to keep the car comfortable for many hours that it's not being driven.�
Dec 25, 2012
cinergi I can confirm first-hand that HVAC is off when car is off. The car is so well insulated that cabin temperature is surprisingly high when cold outside.�
Dec 25, 2012
mknox Could be a greenhouse effect. I have a black (ICE) car, and have come out to it parked for many hours in sub-freezing but sunny weather and have actually had the auto a/c try to come on upon starting the car, because the interior is already above the setpoint.�
Dec 25, 2012
surfingslovak I just remembered reading the following blog post by tomsax earlier this year. He describes how his Roadster did while he and his wife were away on a three-week vacation trip. Perhaps it provides some additional perspective.
Click to open
�
Dec 25, 2012
Raven Well it seems to me that it's a programming issue then. The roadster pack was 80kwh right? Warming a pack that size should be close enough in similarity although the cells are positioned differently.�
Dec 25, 2012
dsm363 The Roadster has a roughly a 53 kWh pack. The Model S doesn't have the storage mode the Roadster has though but I would think this could be fixed in software as well.�
Dec 25, 2012
surfingslovak Yes, I think that it would be reasonable to expect similar behavior. If not now, then perhaps in the future. Although the pack in the Roadster was rated at only 53 kWh, its weight, and by extension its thermal mass, is roughly similar: 992 pounds. The only significant difference is that the bottom-mounted battery in the Model S exposes a much larger surface area to ambient air. Still, an implied energy use of more than a couple kWh per day to condition the pack in very cold conditions seems to be excessive. I'm participating in a BMW field trial, and although the ActiveE has an active thermal management system, we have not heard any similar reports to date.�
Dec 25, 2012
setritt now this we need - i'm sure there are many people with a model s who are either going to go away on vacation and leave the car at home plugged in or at the airport. should be a top priority IMO�
Dec 25, 2012
dsm363 Storage mode in the Roadster didn't reduce the vampire drain as far as I know. With v4.0 on the Model S, if you have displays set to turn off then that's basically a sleep mode. Maybe they'll come up with something that uses even less power but they're saying it is now 2 miles of range a day compared to 8 before. If you have the car plugged in there there is less to worry about.�
Dec 25, 2012
jerry33 I think the real problem here isn't the vampire load, it's that the end time of charge can't be set. If you could do that then the charge would be complete at the time you set and the vampire load wouldn't enter into it (unless you weren't plugged in) because you'd be driving shortly afterwards.�
Dec 25, 2012
mattjn It seems to me that the lack of a charge timer is a huge oversight on an EV vehicle. Even on one rushed to production to meet certain quotas and deadlines.�
Dec 25, 2012
dsm363 I still find it odd it was left out. It has to simply be a software issue that they are working on for a future update but don't know what the delay is. They had it in the Roadster. Maybe they are skipping a simply charge at X time feature and going for something more complex and it is taking a long time. Can't really think of any other reason.�
Dec 25, 2012
tezco I've been plugging in my car about every other day but haven't been out on the road due to a cold. Time to charge has been estimated by the S to be 1.5 hours each time on 240 at 30 amps. Seems like a lot of charging needed for no driving. Garage temp is around 30.�
Dec 25, 2012
cinergi If it's based on SOC, then it's at 230/229 rated miles (I've been watching closely today).
Plugged in with MC at 240/40, software 4.1, sleep mode is OFF.�
Dec 25, 2012
Larry Chanin Hi Ben,
Thanks for the reporting. How many hours has the car been plugged in so far?
Thanks.
Larry�
Dec 25, 2012
cinergi Since ... either Friday or Saturday -- I can't remember which. I'm sure it's had more than the two maintenance charge cycles that I've observed since then -- just wasn't watching until recently.�
Dec 25, 2012
dennis I assume Sleep Mode OFF=Keep Displays Powered is set to OFF (I still don't have 4.X, just looking at the release notes). That being the case, what is the range loss in 24 hours?�
Dec 25, 2012
dsm363 Wouldn't keep displays powered set to off be equal to sleep mode on?�
Dec 25, 2012
Larry Chanin Yes.
Larry�
Dec 25, 2012
M_Mike It seems to me that the car is simply trying to maximize battery life. Until there is a way to let the car know what time you intend to drive again (via the upcoming app and timed charging option) it doesn't know whether you will need it in 8 hours or 8 weeks - therefore it is going to allow the SOC to decrease naturally until the optimal storage SOC is reached. I haven't read (or maybe I missed) what happens when the battery gets to its optimal SOC level? Does a plugged in vehicle then begin intermittent charging as necessary to keep the battery pack at the optimal storage SOC? What is the optimal storage SOC of a plugged in battery pack? I am guessing it is somewhere around 50% or less?�
Dec 25, 2012
MikeK 30 miles in one day is not "decreasing naturally", though. If that figure really does reflect the SOC of the pack, a lot of energy is going someplace besides natural discharge of the battery and minor parasitic loads.�
Dec 25, 2012
dennis Reading the release notes the section title is Vehicle Sleep but the control is Keep Displays Powered (Off/On). Easy to get confused.�
Dec 25, 2012
Larry Chanin Cinergi has reported that even after a number of days, when left plugged in the range hasn't dropped below 231 miles of rated range when charging in Standard mode. That's about 87% of full capacity. It is definitely not letting the SoC to dip to optimal storage levels. (I have not seen my range dip below the mid 230's when plugged in in Standard mode for around a day or less.)
Larry
- - - Updated - - -
From my experience I would guess that my "loss" of 30 miles overnight (less than 12 hours) was not completely a loss of energy, but rather something to do with the manner in which the car calculates range when cold. When I warmed up the car with a charge the range was restored faster than the charging rate of the connection.
Larry�
Dec 26, 2012
Brian H IIRC, the fabled Web App will/does include both control over cabin temps, & time to have max/standard SOC available for the driver's return.
I.e., it should be possible to set, say, 7 a.m. tomorrow as a departure time, and specify full standard charge and cabin temp of 72�F, and have the app arrange all of that seamlessly.�
Dec 26, 2012
tezco Judging from the number of 12V battery failures mentioned elsewhere in the forum, I suspect that the parasitic loads may still not be "minor". But, we don't know how many folks with 12V failures have sleep mode available and turned on, and how much damage was done to their 12V prior to getting the update (still a lot of us out there without the update to 4.x).
The SOC bar graph in my LEAF doesn't seem to change much with changes in battery temperature, so it must be a calculated SOC that compensates for battery temp. Unfortunately, the true range does decrease in the cold such that each "bar" gives you fewer miles, particulary when the temps get near 0[SUP]o[/SUP] F, and especially if you run the heat at a typical ICE-type setting.�
Dec 26, 2012
EcoHeliGuy In many of Tesla's videos about the model S of the years they talk about the car learning when to pre heat the cabin.
Im not sure if this feature is in the car yet, but is it possible these cars are warming up to be driven at a certain time, day after day while being parked. And is it possible that if the cabin doesn't do this yet, that the battery pack is? Maybe the battery pack has two stand by temperutre settings, warm enough to not harm while driving (never goes below this one), and warmer to give more optimum range. Both of these temps below optimum regen.
So at the airport the car might be trying to maintain 32�, and then each day at 8am and 5 pm it brings the battery pack up to 50� expecting to go do a drive?
also its next to impossible in measure SOC. the computer is working crazy algorithms and past performance to guess the SOC. This is why so much range and usage information is available to the driver, this information is already needed for SOC calculations. The tempeture drops plus sitting around for Long periods would have major effects on estimates, hence while range is coming back once driven and faster then expected when charged.�
Dec 26, 2012
surfingslovak Yes, that's possible. If my calculations were correct, then it would take about 0.5 kWh to raise pack temperature by 10 degrees. Assuming that this energy will be then dissipated, and will need to be replaced, you can likely bank on something between 3 to 6 kWh each 24 hours in this particular scenario.
Obviously, that would depend on how cold it was outside, and how long the pack was conditioned at 50�. I tried to estimate the energy dissipated from the underbody. It's tricky, and I could be wrong, but I'm getting figures around 20 Watts for radiant heat transfer and about 300 to 400 Watt for heat convection. This means that to maintain pack temperature of 50�, when the ambient is near the freezing point, about 0.3 to 0.5 kWh would be required each hour, on average.
That's indeed a very fundamental shortcoming, and it will hopefully be corrected by a future software update, given Tesla's track record and credibility as innovator in this space. Personally, I would really like to see the kWh estimate used internally to compute range figures. Even if this number changed based on temperature or some other factors, I think exposing it would be both beneficial and educational.�
Dec 26, 2012
teddyg Hi guys,
I concur with SurfingSlovak here...they car should definately have a basic kWh remaining indicator as well as the range/miles indicator...in my EV that I have had for ten years (Solectria Force) ALL I have ever had is a kWh display and you knew that 0.0 was fully charged and that 30.0 was dead (not sure why it counted up rather than down but that's how it worked). I enjoyed that I could make the calculations myself based on my driving but I can see that for longer trips a mileage indicator can be useful as well.
At any rate I am just surprised to see that people were not specifically told by Tesla when making a reservation or certainly when taking delivery to be very careful with the car in cold temperatures. Previously I had been going off the following article when determining parasitic load or "bricking":
http://news.cnet.com/8301-11386_3-57384571-76/tesla-you-cant-brick-model-s-batteries/
In the article it says that Tesla claims it would take "a full year" to brick a Model S if you left it unplugged with a 50% state of charge. Perfect I thought and told all my friends/family in Canada to not worry about a Tesla in cold weather.
Obviously from customer statements here clearly Tesla meant that it MIGHT take a full year to run down the battery IF the car sat in perfect room temperature conditions the entire time.
With reservations in places like bitter cold Norway now leading the E.U. I think it is absolutely imperitive that Tesla be extremely honest with potential customers about the car's performance/range in cold weather.
It is better to risk a sale than risk lawsuits from those in cold temperature climates claiming that they were not accurately informed about the car's cold weather performance.
I am hoping advancements in battery chemistry and improved efficiency in EV thermal management systems will help with this problem soon...clearly battery capacity isn't the only area where improvements must be made...hopefully by Gen III a lot of progess will have been made.�
Dec 26, 2012
teddyg Just to add I think Tesla should put a chart in the Model S owner's manual clearly showing affect on range and parasitic load when parked in certain temperatures (both hot and cold)...they could also put a link to this chart on their website...potential buyers should be given this information and have the opportunity to judge for themselves if it is an issue for them or not.
I think most Tesla buyers realise that as a first adopter there are certain quirks that they are willing to deal with in exchange for a cutting edge product...however if they aren't told that their car is going to lose 25 miles of range every 5 hours it is parked in sub-zero weather and they happen to leave their car at an airport for two weeks in winter...they will be very upset to find a "bricked" Tesla that needs a new battery pack!
Honesty in cold/hot weather MUST be forthcoming from Tesla ASAP from what I can see here.�
Dec 27, 2012
stevezzzz I posted something relevant on another thread: Time from Standard to Range - Page 4
I was writing about the daily top-off charge when the S is plugged in, but I don't know if there is a lower, semi-continuous draw for battery conditioning when ambient temps are low. The overall impression I get from reading these threads is that the behavior is not consistent for everyone.
BTW, I've never seen a rated range under 230 miles or over 241 miles (standard charge mode) when plugged in continuously.�
Dec 27, 2012
JRP3 I suspect that at some low SOC the car and pack shuts down completely, preventing any further drain, so that it could indeed sit for a year without killing the pack, regardless of the climate. Yes if it's sitting in a hot climate it will age the pack faster without any cooling during that time period.�
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