Power drain while idle (Vampire Load)

[RichardC]

While I have not yet taken a sufficient number of measurements to confirm an improvement, I have seen around 4.5 kWHr vampire losses per day since upgrading to version 4.3 software. Indoor storage at 5 degrees C (41 degrees F) ambient, 10 degrees C (50 degrees F) interior temperature. I had previously seen around 5 kWHr per day under version 4.2, but the difference may be attributable to slightly lower temperatures during the prior measurement period. In either event the losses are still way too high and harm the otherwise excellent environmental pedigree of the car.

 

[ShortArc]

I definitely saw quite a bit of variance with temperature. I discarded those data points for this discussion (there were 6kWh days). I am also running 4.3 since it was released and in a week or so will post if I see any definitive improvements. We need sleep mode...!!!

 

[IlliniT]

I think he means Controls>E-Brake/Power Off>Turn Power Off

In my experience this doesn't change anything with the vampire load, it just shuts the screens off with the door open.

I honestly believe that turning the power off decreases battery drain for whatever reason especially in cold weather (Chicago). I've now tried it multiple times (starting with the charging issues I was having) and it really does appear to maintain charge significantly better. Just my 2c.

 

[qwk]

I honestly believe that turning the power off decreases battery drain for whatever reason especially in cold weather (Chicago). I've now tried it multiple times (starting with the charging issues I was having) and it really does appear to maintain charge significantly better. Just my 2c.

Page 3 of the owners guide also confirms my experience, although the firmware version the car is on most likely affects it.

- - - Updated - - -

I honestly believe that turning the power off decreases battery drain for whatever reason especially in cold weather (Chicago). I've now tried it multiple times (starting with the charging issues I was having) and it really does appear to maintain charge significantly better. Just my 2c.

Page 3 of the owners guide also confirms my experience, although the firmware version the car is on most likely affects it.

 

[4sevens.com]

I think he means Controls>E-Brake/Power Off>Turn Power Off

In my experience this doesn't change anything with the vampire load, it just shuts the screens off with the door open.

I have noticed that if I do "turn power off" that the fans and pumps will immediately turn off whereas if I just walk away from the car and lock it often fans and pumps will still run.

Even if it doesn't have significantly lower power consumption I think it's worth it to do it and create a habit of doing that so that when they figure out how to make it "hibernate" the habit is already there to shutdown the car when leaving it for extended periods of time.

 

[ShortArc]

I have noticed that if I do "turn power off" that the fans and pumps will immediately turn off whereas if I just walk away from the car and lock it often fans and pumps will still run.

Even if it doesn't have significantly lower power consumption I think it's worth it to do it and create a habit of doing that so that when they figure out how to make it "hibernate" the habit is already there to shutdown the car when leaving it for extended periods of time.

Even though I would have to agree that "Power Off" will have some energy savings (15 mins before auto-shut down) and those savings would certainly depend on the frequency you do a complete power up / auto-powerdown, for longer term it has no practical effect what so ever. Personally I do not want to get used to shutting down anything manually

 

[yobigd20]

2.76 mile/hr range loss *EVERY HOUR* while not plugged in.

Just to show everyone that I wasn't making my numbers up above, I monitored my idle loss today. Here are the pics to prove that I see close to 3 miles/hr loss while idle and unplugged. Parked my car at 6:00am and had 172 mile range left (didn't take a pic there), but I took a pic once an hour for the rest of the day until I picked up my car.

To recap, stared off 6:00am @172mile
7:28am @170mile
8:29am @170mile

9:30am @169mile
10:36am @164mile
11:34am @157mile
12:36pm @154mile
1:33pm @151mile
2:31pm @148mile
3:31pm @146mile
4:30 @ 143mile


172-143 = 29mile loss
6:00am-4:30pm = 10.5 hours

29 mile loss / 10.5 hours = 2.76 mile/hr range loss. This is what I see *EVERY DAY* I am at work. It has been about 40 degrees during the day for the last few weeks. These results are consistent daily. That's 1% loss PER HOUR.

If it continued like that for 24 hours, the loss would be about 65 miles, approximately 24-27% total battery charge loss per day. that is an absurd loss for a few hours. not happy about this, I hope they fix this problem in 4.3

also interesting to note, was that the 12:36pm and 1:33pm incorrectly showed the charge port as open. Must have been a bug in the mobile software. Also just in case anyone asks, when I got back to the car it also showed 143mile range left so there isn't any inconsistency between rate on mobile app vs the car itself. And this is self-park garage. Not valet, lol. Nobody's taking joy rides in my car. It just sits in the parking lot losing 3 miles per hour range if I don't plug it in.

- - - Updated - - -

Also, am I the highest range loss per hour that any of you know about? I'm wondering if this is normal loss for everyone else..... doesn't sound like it though.

 

[ShortArc]

yobigd20, those numbers are absurd. Not sure if you posted earlier but have you contacted TM tech support or your local service center? It would appear there is more going on here than the "normal" parasitic load we are all seeing.

 

[kevincwelch]

I get losses during the day as well. They are heavily influenced by temperature, but not as badly as you seen to have. At below freezing temperatures, I lose about 1-2 miles per hour.

I call BS on the whole claim that those miles are regained when the car heats up. I never see them return...not at these temps.

Sent via Tapatalk.

 

[SuperCoug]

Yobig20, do you have anything plugged into your USB ports? My buddy's Caddy was having all sort of battery problems (frequently the battery would be dead in the morning on his brand new car) but it culprit turned out to be an iPod connection kit plugged into his USB. The dealer claimed that even a USB memory stick could consume an insane amount of juice.

Just a thought.

 

[yobigd20]

yobigd20, those numbers are absurd. Not sure if you posted earlier but have you contacted TM tech support or your local service center? It would appear there is more going on here than the "normal" parasitic load we are all seeing.

not yet, but based on everyone's reactions it looks like I'll be making that call now.

Yobig20, do you have anything plugged into your USB ports? My buddy's Caddy was having all sort of battery problems (frequently the battery would be dead in the morning on his brand new car) but it culprit turned out to be an iPod connection kit plugged into his USB. The dealer claimed that even a USB memory stick could consume an insane amount of juice.

nope, nothing plugged into USB. I have no idea what it could be.

 

[ChadS]

I call BS on the whole claim that those miles are regained when the car heats up. I never see them return...not at these temps.

I am sorry you don't see them return. I do see them return. Maybe our temps are different...what temps are you at? I usually lost miles overnight slightly below freezing, and they returned during the day somewhat above freezing. If you are below freezing even during the day while driving, things may be different.

Another possible difference...when I took my last road trip where I left the car out overnight, I had pretty old firmware. I'm now on 4.3 but have not tried it again. It's possible the behavior is different (in fact the release notes make it sound like 4.3 has a different means of calculating remaining capacity in the cold...but no more detail than that).

Just to be clear, the number on the range meter never goes up (at least not that I've noticed). But if you calculate how many miles you should have consumed, and compare it to how many the range meter says you used, you can see that they weren't really all lost.

Also to be clear, not ALL of the lost miles come back. There really are a few miles that get lost every day, and it's enough to be very annoying.

 

[qwk]

^^^ Yes, you do lose miles, sometimes as many as 40 overnight, but the real range lost is not that drastic. I think the pack calculates capacity at whatever temp it is at that particular time. For my car, the vampire drain is around 10 miles per day above 40 degrees F, but if the temp drops to below freezing, the instrument panel can show as much as 4 times that loss(rated range). I will agree that the vampire drain is very annoying.

 

[yobigd20]

For my car, the vampire drain is around 10 miles per day above 40 degrees F, but if the temp drops to below freezing, the instrument panel can show as much as 4 times that loss(rated range). I will agree that the vampire drain is very annoying.

Ok so this is normal behavior then. I don't want to stir up any problems with Tesla if this is expected. I am still on 4.2, haven't got the little upgrade button yet so I'll wait until then and monitor it again.

 

[ShortArc]

There is so much we do not know about the actual charging process and static loads...
We are told by TM that when the cars is at rest, the battery's thermal management is at rest as well. We can reason that when the temperature drops the system re-calculates the range based on that new temperature. This would seem logical as the battery has thermal mass which needs to be warmed for optimum performance. If the surrounding temperature goes up, so will the temperature of the battery pack, consequently the range values change. The only way to know if there are other "vampire loads" at work when the temperature drops is to data log power as a function of temperature while being plugged in for a few days. Maybe the car even stores this kind of information?
In any case I can not believe that yobigd20's readings are 'normal'. But maybe heating the pack really is the main contributor to the additional power drain...but that much? I would send my iphone pics to TM and asked them to comment!

 

[mknox]

Yobig20, do you have anything plugged into your USB ports? My buddy's Caddy was having all sort of battery problems (frequently the battery would be dead in the morning on his brand new car) but it culprit turned out to be an iPod connection kit plugged into his USB. The dealer claimed that even a USB memory stick could consume an insane amount of juice.

I dunno. I traded in an '09 Cadillac CTS and I had the iPod dongle thingy too. It was never unplugged for 4 years and I never once had any battery problems with the car.

- - - Updated - - -

I get losses during the day as well. They are heavily influenced by temperature, but not as badly as you seen to have. At below freezing temperatures, I lose about 1-2 miles per hour.

I call BS on the whole claim that those miles are regained when the car heats up. I never see them return...not at these temps.

That is consistent with what I'm seeing (a little less when the car is in an unheated, but warmer than ambient garage). I've also never seen the range numbers "come back" and yes, they continue to deplete at a typical rate when I drive.

 

[tezco]

I am sorry you don't see them return....Just to be clear, the number on the range meter never goes up (at least not that I've noticed).

My experience is similar. Often I will start out on a trip and the ideal range figure stays nearly constant, once holding very near the starting point for nearly 30 miles. (Elevation and temperature changes were minimal.)

(v4.3 (1.25.35) is supposed to lessen this, if I understand the release notes correctly.) I have noticed that after the upgrade, my ideal miles immediately after a standard charge went from 273 to 278.

- - - Updated - - -

Here are some figures comparing the various idle power losses, depending on firmware. It looks like the latest firmware has improved slightly over v1.19.42 Note the idle power losses of the Leaf (the square purple data points on the first graph -- these represent 0.05 kWh per day idle power losses). Clearly we have a ways to go before we can park our S's for months on end without significantly depleting the battery.

 

[ShortArc]

Very informative tezco!
It also shows that yobigd20 static losses are way too high.
I still do not understand why there would be in increase in "kWh-Drawn From Wall" with decreasing temperature. If we can believe TM that thermal management is not enabled, so what causes this? I am somewhat lost here....

 

[tezco]

Very informative tezco!
It also shows that yobigd20 static losses are way too high.
I still do not understand why there would be in increase in "kWh-Drawn From Wall" with decreasing temperature. If we can believe TM that thermal management is not enabled, so what causes this? I am somewhat lost here....

I'm guessing there is some battery heating taking place.

 

[RichardC]

Silencing the Vampire - A troubling element of the vampire losses on our Model S was the electric motor soundtrack which I heard at all times, whether the car was on charge or not, and which continued even when the car was unplugged. While it was a relatively quiet motor, it was running all the time and seemed to be somewhere in the front half of the car. Picking up on a suggestion earlier in this thread, I have taken to turning the car off (on the main screen) whenever parking it, and this past weekend measured the power consumed to keep the battery topped up. During the first 24 hour period I turned off the car without getting in and was pleased to hear that the motor noise stopped. The next daily top up used 4.3 KWHrs of electricity. While this is better than the 5.3 KWHrs/day that I measured over the course of the month of February (with the version 4.2 software) it was not much better than previous tests with the version 4.3 software. More troubling was the fact that the pesky electric motor was turned on again by the charging cycle and continued running after the charging was complete. I powered off the car again and silenced the motor and left it for another day. This time the top up used 4.03 KWHrs of electricity, which is still inexcusably wasteful, but is better than I have previously seen, and the electric motor remained off after the charging was complete.

Have others noticed the electric motor noise and/or seen any benefit from manually powering down the car whe leaving it? Does it make any difference whether you sit in the seat when powering it down (I had the impression that a number of additional systems are powered up whenever you are in the driver's seat)? The car is indoors with the temperature around 9 degrees C (or around 48 degrees F). By way of reference 5.3 KWHrs/day corresponds to around 220 Watts of continuous power consumption, 4.3 KWHrs/day corresponds to around 180 Watts of continuous power consumption, and 4.03 KWHrs/day corresponds to around 168 Watts of continuous power consumption.