Power drain while idle (Vampire Load)

[ElSupreme]

On a related note I finally got my home desktop to sleep properly. I am now saving about $15 a month in power (probably only about $10 since I turned off my AC)! So yes these things do consume real amounts of power.

[arg]

Most microprocessors have low-power idle modes, sometimes various alternative modes, where the processor goes to sleep until an interrupt occurs. If they can put processors to sleep this way then they can have very low-power idle and instant wake-up. They might have to do some firmware magic to get it to work, but that's a "simple matter of software" (quotes are for irony purposes). That's what "sleep" mode is on your notebook computer.

Yes, but this doesn't really match up with the loads people are reporting - even if left fully running, these CPUs would only be a couple of watts, yet people are reporting figures like 500W. We know that the two 'big' processors running the instrument display and touchscreen are Nvidia Tegra (as used in tablets) which have idle power management in normal operation. Those are probably the only processors in the car running a heavyweight OS that would need significant reboot time.

So, it could be something mechanical causing these loads (someone upthread mentioned brake servos, also there's battery cooling), or it's death by a thousand cuts in all of the minor subsystems contributing the odd watt here and there and just adding up to a big total. It may be a long slog to fix it rather than a single big win.

[Ceilidh]

Seems to me that Tesla could make this user-selectable. Clearly the instant on capability is there is your are less energy / cost conscious. Would be nice to have an eco-mode for this that turns the car off unless the battery temp needs to be adjusted, but otherwise turns on when the door is opened or when the driver sits down or something. Shouldn't be too hard to program given that the sensors are already in place and such.

[brianman]

Seems to me that Tesla could make this user-selectable. Clearly the instant on capability is there is your are less energy / cost conscious. Would be nice to have an eco-mode for this that turns the car off unless the battery temp needs to be adjusted, but otherwise turns on when the door is opened or when the driver sits down or something. Shouldn't be too hard to program given that the sensors are already in place and such.

Maybe they should hae some kind of, well, "Storage Mode"...

[DrComputer]

I also think people have taken the "lost 10 miles in 24 hrs" number at face value. The S, just like the Roadster does not always show accurate mileage estimates after charging. It takes some time for the battery pack to settle and balance itself after charging. I think the actual loss is probably closer to 1 mile per day than 10.

[FlasherZ]

I also think people have taken the "lost 10 miles in 24 hrs" number at face value. The S, just like the Roadster does not always show accurate mileage estimates after charging. It takes some time for the battery pack to settle and balance itself after charging. I think the actual loss is probably closer to 1 mile per day than 10.

Let's hope so. I live 60 miles from the airport and I take business trips that average 10-14 days long. I'd hate to come back from my trip and find that I don't have enough miles to get back home.

Of course, I've found a couple of airport parking facilities that will let me have a NEMA 5-15 while I'm parked there, so I think I've mitigated that concern -- but if they're occupied or busy, I might have to bank on my miles still staying up there.

[rolosrevenge]

+1 Tommy, Doug_G: I was surprised at the $14/month cost. Did the math myself and I agree with your numbers. My power in the Pacific Northwest is cheaper at 0.09/kWh but still its $8 per month. Whoa, yes I also hope this is remedied.

Its like running 500W electric 'space heater' in your garage 6 hours every day! (3000/500=6). Atsa lotsa watsa!

Unless, of course, you would have been running that space heater anyways (it's cold up here), then it is costing you nothing.

[vfx]

...Mind you, the Model S has flash memory, not disks, and there may not be enough storage to do that.....

Maybe this type of software upgrade is why they have not opened the memory to owners yet.

[Cottonwood]

I also think people have taken the "lost 10 miles in 24 hrs" number at face value. The S, just like the Roadster does not always show accurate mileage estimates after charging. It takes some time for the battery pack to settle and balance itself after charging. I think the actual loss is probably closer to 1 mile per day than 10.

That is exactly what I have seen. There is a big drop the first day after charging, then a much slower drop on succeeding days. Am I the only Model S owner that has gone multiple days without driving it?

[dsm363]

Let's hope so. I live 60 miles from the airport and I take business trips that average 10-14 days long. I'd hate to come back from my trip and find that I don't have enough miles to get back home.

Of course, I've found a couple of airport parking facilities that will let me have a NEMA 5-15 while I'm parked there, so I think I've mitigated that concern -- but if they're occupied or busy, I might have to bank on my miles still staying up there.

I think you'll be fine even without charging but of course if you have it, take advantage of it at the airport.