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)
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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)
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.
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.
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.
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.
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.)
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.
Currently there is only one sleep setting on version 4.0 or 4.1. Displays are set to either power off or not.
Larry
surfingslovak
Member
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/K
specific 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.
Based on some prior work on MNL and 0.8 J/g/K
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.
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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.
mknox
Well-Known Member
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.
surfingslovak
Member
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 opentomsax said:
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
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.
surfingslovak
Member
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.
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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
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.
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.
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