Power drain while idle (Vampire Load)

[Jeff Miller]

I've never noticed any noises from my car when it's parked, in contrast to the Volt which was occasionally quite noisy.

 

[JRP3]

Could the noise be a coolant pump for the pack?

 

[mknox]

I have heard the pump noise, both when charging and when sitting idle, but it is certainly not on all of the time.

 

[Larry Chanin]

I have heard the pump noise, both when charging and when sitting idle, but it is certainly not on all of the time.

Same here.

I was wondering in cold climates in future firmware upgrades dealing with "Vampire" load there might be an advantage to having the option of limiting the amount of battery heating until such time as the car is expected to be driven. For example, on a cold Canadian evening while you are asleep does the battery pack have to be continuously heated? Say you set your timer to have the car charged by 7:00AM the software could also preheat the battery pack only before you need to drive.

My understanding is that, within reason, cooling a battery preserves the life so in addition to reducing Vampire load such a firmware upgrade might also slightly improve battery life.

Larry

 

[qwk]

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.

I have found that temperature is the biggest factor, and powering off the car via the screen just powers it down a few minutes faster than just parking it. Very little difference there. Temps below 45-50 F is what really suck the juice down.

 

[mnx]

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.

I recently left my S sitting at home for 8 days in the garage unplugged. The dash said 217km rated. I took it for a spirited ~15 minute drive, consumed 2.8kWh and the display read 219km rated when I got back. This is the first time I've seen range "come back", but it's also the first time I've let the car sit for any amount of time...

 

[ShortArc]

I have heard the pump noise, both when charging and when sitting idle, but it is certainly not on all of the time.

Same here. Mostly the car is quiet.
Also the last 8 days my static load is down to about 2.9KWh from 3.6kWh. Garage temp must be going up...

 

[RichardC]

Could the noise be a coolant pump for the pack?

I am increasingly certain that is the case. The seems to be emanating from the front of the car. I would very much like to get a shop manual so that it would be possible to better understand what is going on under the covers.

 

[Jeff Miller]

Same here.

I was wondering in cold climates in future firmware upgrades dealing with "Vampire" load there might be an advantage to having the option of limiting the amount of battery heating until such time as the car is expected to be driven. For example, on a cold Canadian evening while you are asleep does the battery pack have to be continuously heated? Say you set your timer to have the car charged by 7:00AM the software could also preheat the battery pack only before you need to drive.

My understanding is that, within reason, cooling a battery preserves the life so in addition to reducing Vampire load such a firmware upgrade might also slightly improve battery life.

Larry

Is the battery continuously heated (or cooled)?

From what I understand, the battery temperature must be warmed to above
freezing in order to charge.

But if the battery is already charged, or if temperatures are above freezing, will the battery heater turn on?

It would be very strange if it did, given that, as you note, cold temperatures are actually good for the battery.

I think most of the vampire loss is from the electronics and not from heating the battery, but I don't have good data to back this up.

 

[CaptDaveHowe]

Energy used while in park?

I just took delivery of my Model S and charged for the first time last night. Started out with 180 rated miles. An update took place around 11 am for 2 hours and at 2 pm the rated miles was down to 171. What is the normal energy use for the car when not in use? Is there a way to turn systems off?

 

[jerry33]

Well, the update would have taken a lot of energy. During updating the car starts and stops a few times. There is a video of an update here. See the Vampire thread for discussion on energy used while parked.

 

[CaptDaveHowe]

Thanks Jerry. Vampire thread?

 

[rabar10]

Thanks Jerry. Vampire thread?

Here: (posts merged into thread, link removed)

 

[pbrulott]

I am increasingly certain that is the case. The seems to be emanating from the front of the car. I would very much like to get a shop manual so that it would be possible to better understand what is going on under the covers.

@RichardC, your observations are similar to mine i.e.:

- loss of 20km+ per day (my garage these days is at 11C (52F))=> which looks like it corresponds to Vampire load
reported in this thread
- car gets noisy towards the front when I approach the car with the keyfob. I noticed 2 use cases 1) when my climate control is on (it's off most of the times these days) I hear funny noises in towards the front and 2) when climate control is off, a compressor noise coming from the front that I assume to be the battery heater

 

[tezco]

I'm still on v1.25.35, and still collecting data. I also started plotting the power loss vs my garage temp 1 hour prior to beginning charging (thought perhaps that this would better correlate with the actual temperature of the battery vs using the average between charge temperature [that could stretch over several days at times], but the plots don't seem to look any different.)

 

[brianman]

Nonscientific data point...

While the weather has been rising (and is potentially the real cause), it's worth noting that my morning charge was 232-233 miles (consistently) on 4.3 and has been 237+ miles (consistently) with 4.4 firmware.

 

[RichardC]

Further long term energy loss test

As a follow up to the test performed in February which found an average vampire loss of 5.3 KWHr per day (measured over a four week period), I have tested the power loss over a 12 day period in April. The differences from the earlier test are as follows:

February Test: Software v.4.2, car left plugged in and recharging daily, car not manually powered off, temperature 40 to 50 F - Result - Average energy loss 5.3 KWHrs/day over 28 days

April Test: Software v.4.3, car left unplugged and recharged at end of period, car was manually powered off, temperature 50 to 60 F - Result - Average energy loss 3.9 KWHrs/day over 12 days - This rate of energy loss corresponds to an average loss of approximately 16 KM (10 miles) in rated range per day and about 163 Watts of continuous energy consumption.

 

[Jeff Miller]

I had a dedicated meter installed on April 4th. Yesterday, I looked at the totals. Over the 21 days, I drove 278 miles. The car says I used 92kwh, for an average of 331 wh per mile. My wall meter says I used 160kwh total. So 68 went to charge the battery (I'm guessing around 8 or so of the total), power the electronics, and manage whatever battery heating and cooling occurs (over this range of temperatures, I don't know if there should be any battery thermal management). This works out to about 3.2kwh per day, a bit lower than RichardC's but in the same ball park. So overall, more than 40% of my power consumption is unrelated to driving. Temperatures ranged from low thirties to maybe 70, with the median probably in the 40's and software is 4.3. Car was not powered off. Car was plugged in every night.

Bottom line: Tesla needs to make restoring sleep mode a high priority.

 

[Seegem]

I agree. My math works out to be about 4.7 kWh per day. thats... crazy! I've taken to charging and then unplugging the car..just in protest

I had a dedicated meter installed on April 4th. Yesterday, I looked at the totals. Over the 21 days, I drove 278 miles. The car says I used 92kwh, for an average of 331 wh per mile. My wall meter says I used 160kwh total. So 68 went to charge the battery (I'm guessing around 8 or so of the total), power the electronics, and manage whatever battery heating and cooling occurs (over this range of temperatures, I don't know if there should be any battery thermal management). This works out to about 3.2kwh per day, a bit lower than RichardC's but in the same ball park. So overall, more than 40% of my power consumption is unrelated to driving. Temperatures ranged from low thirties to maybe 70, with the median probably in the 40's and software is 4.3. Car was not powered off. Car was plugged in every night.

Bottom line: Tesla needs to make restoring sleep mode a high priority.

 

[mknox]

I agree. My math works out to be about 4.7 kWh per day. thats... crazy! I've taken to charging and then unplugging the car..just in protest

That really won't help. This issue is akin to having a leaky gas tank. If you simply stop topping the tank up, at some point you're eventually going to have to replenish the loss.