Battery to 0 overnight

[R.S]

And how would a regular heater work if the battery is too cold to draw power? I don't think you understand how Tesla is using the powertrain to generate heat without moving the car.

arnold

To be honest, nobody really knows if and how Tesla does it. All I've seen is pure speculation.

Quick update! So I did end up leaving my car out last night, temperatures dropped as low as 28 degrees F. Car dropped from 132 to 117 Miles. Much better than 100 drop . Before I went to bed I did notice that my interior temperature was holding a solid 65-70 degrees as i monitored it for an hour (even though outside temp was 33). Before going to sleep I decided to switch off my Bluetooth maybe thinking proximity had anything to do with maintaining temperature or what others have said maybe my car is turning on and off. Anyways, happy it didn’t happen again for now.

Maybe you could try it again with your bluetooth on? AFAIK the car has 4 bluetooth sensors and it probably uses those to estimate your location. So maybe if you are sleeping above the car (you said your room was right above the car) it might think you are in it and keeps the heat on?

 

[Mulligan Jake]

@Mulligan Jake : What's up with the disagree to my post at Battery to 0 overnight ? What is "correct" in your mind?

That was a fat finger mistake on my part, appologies

 

[pcpro]

Phantom screen touches causing the car to turn on and heat the car?

 

[SigNC]

Phantom screen touches causing the car to turn on and heat the car?

Phantom screen touch has been an issue. EAsy way to diagnose is to launch the sketch pad and see if it gets anything on it without you touching.

 

[hacer]

...

For a bulk heating situation with wide temperature margins and high thermal mass, a properly sized heater element like the S or X have is perfectly functional. Turn on at the lows set point and off at the high set point, no need for an exact match to heat loss.
...

It's functional, but not "perfectly" because it has a minimum power draw that is larger than the minimum EVSE connection. So if you only have a 120V outlet to plug into, and the battery is already at a low protection level, the model S and X will not use the 1.4kW available to heat the battery. The reason is that you can't PWM the heating element without it's own inductor because during the off phase you will cause charging of the battery resulting in dendritic growth. Thus below a certain charge threshold and temperature no battery heating will occur even if doing so could have raised the battery temperature to a point where charging could eventually be possible. The model 3's strategy theoretically allows fine control to work across a broad range including the full range of available AC sources.

 

[hacer]

... Balancing is only active near the end of a charging session.

I wasn't trying to say that the balancing resistor was loading any of the cells (actual balancing), but that the control IC that can turn on that resistor is still powered by those cells; it has a direct connection to the cells and can't be turned off. But it only has a typical 12uA (max 20uA) in its sleep mode so about 60 Wh per year from a deeply discharged battery, less than the bare cell self-discharge. So yeah, probably not catastrophic.

 

[hacer]

Picked up my model 3 just a few days ago. Has anyone had issues with their model 3 and a drop in battery overnight? My battery was about 100 Miles, and in the morning it was 0. This seems incredibly odd and way too significant of a drop. Software issues potentially?

I just got back from a week-long trip where both my model 3 and model S were left unplugged inside the garage, side-by-side for 7 days.

The model S (which I set to energy savings, Not always connected) lost only 6 miles. The model 3 which didn't seem to have any control settings for sleep lost 48 miles! It still had 153 left but it clearly doesn't have great power savings in the software. When I first got in the garage I could hear it making a humming noise like a pump was running or something.

 

[C141medic]

The model 3 which didn't seem to have any control settings for sleep lost 48 miles! It still had 153 left but it clearly doesn't have great power savings in the software

That seems like a lot to me in a week for a garaged car. If my math is correct that’s a 24% loss in range.

 

[SFInvestor21]

And how would a regular heater work if the battery is too cold to draw power? I don't think you understand how Tesla is using the powertrain to generate heat without moving the car.

arnold

I understand completely how it works. This one of many reports that the Model 3 battery has trouble at cold temps.

 

[hacer]

That seems like a lot to me in a week for a garaged car. If my math is correct that’s a 24% loss in range.

Yes, I would say that's much higher than it should have been. I'm sure Tesla will fix it in a software update soon. I'm on 2017.50.12 b707518 which I think is already behind.

 

[MikeBur]

Yes, I would say that's much higher than it should have been. I'm sure Tesla will fix it in a software update soon. I'm on 2017.50.12 b707518 which I think is already behind.

The “always connected” is coming, though see if the below is applicable to you. This is something I’ve been troubleshooting with TM

Couple of things I’ve determined from troubleshooting vampire loss drops on wife’s 3 is the sleep state on Model 3 is different than S/X.

• If you’re keeping the tesla app open, or using logging tools, then the car will not got to sleep - on an S/X it will as long as the “always connected” option is checked (this doesn’t exist on 50.12, maybe does on yours?).
• If the car is asleep and then needs to wake, eg to answer a API query, or respond to Bluetooth “key” proximity, it appears to wake up fully. It appears to take upwards of 5 minutes to go to sleep again.

I’m guessing someone will eventually post this “revelation” and it be picked up and the FW as per the manual will be released?

 

[mongo]

It's functional, but not "perfectly" because it has a minimum power draw that is larger than the minimum EVSE connection. So if you only have a 120V outlet to plug into, and the battery is already at a low protection level, the model S and X will not use the 1.4kW available to heat the battery. The reason is that you can't PWM the heating element without it's own inductor because during the off phase you will cause charging of the battery resulting in dendritic growth. Thus below a certain charge threshold and temperature no battery heating will occur even if doing so could have raised the battery temperature to a point where charging could eventually be possible. The model 3's strategy theoretically allows fine control to work across a broad range including the full range of available AC sources.

Well, that is indeed an edge case where having a sub 6kW heating source would open other possibilities.

Is that a realistic case though? After driving a 3 to the point where the pack did not have the energy (nor self heating) to keep in the charging temperature range, will it ever charge off of a 1.44 kW supply that has to power the base load, pump, thermal loss, and still charge the pack? Under what range of temperatures would that amount of power even get the pack warm enough to charge (assuming it would stay warm enough to divert power from heating to charging)?

With 0 base load, the heater running one hour purely from wall power would provide less net heating than the pack providing 4.6kW for 15 minutes ( 6kW-1.4kW from wall 1.15kWh total with less loss to the environment). That is a pack at sub 2% SOC.

There is another factor which may apply in the X/S case. The chargers have the ability to control their output voltage/ current, and a PTC heater still has a power vs voltage curve, so it may be possible that the vehicle could leave the pack disconnected and run the heater at 1.44kW ish.

 

[hacer]

Well, that is indeed an edge case where having a sub 6kW heating source would open other possibilities.

Is that a realistic case though? After driving a 3 to the point where the pack did not have the energy (nor self heating) to keep in the charging temperature range, will it ever charge off of a 1.44 kW supply that has to power the base load, pump, thermal loss, and still charge the pack? Under what range of temperatures would that amount of power even get the pack warm enough to charge (assuming it would stay warm enough to divert power from heating to charging)?

With 0 base load, the heater running one hour purely from wall power would provide less net heating than the pack providing 4.6kW for 15 minutes ( 6kW-1.4kW from wall 1.15kWh total with less loss to the environment). That is a pack at sub 2% SOC.

Well Tesla sells NEMA 6-20, NEMA 6-15, and NEMA 5-20 adapters so there are other cases, none of which can support a > 5kW heater load. Is there a range of temperature where that could matter? Yes. No charging at all is possible slightly above freezing (as a precaution for sensor variation and gradients within the pack). It turns out that temperatures right near freezing are quite common in the natural environment due to the heat of fusion of water, so getting just a little above that can make the difference between slow charging and no charging at all. A cabin with a 6-15 outlet where you're going to stay a few days the difference between no charging at all and 4 mph for 2 days could easily be a big deal. There are posts on TMC about not being able to charge at all in near freezing temperatures with modest (not minimal) EVSE.

There is another factor which may apply in the X/S case. The chargers have the ability to control their output voltage/ current, and a PTC heater still has a power vs voltage curve, so it may be possible that the vehicle could leave the pack disconnected and run the heater at 1.44kW ish.

As far as I know, neither the S nor X actually do this, although it might be theoretically possible. To be fair, I don't think the 3's software manages its "heater" very well yet either, but it is clearly feasible to do so; it is simply a matter of adding whatever desired amplitude (within power handling limits) drive in quadrature to the normal stator drive current. It can be done stopped, in forward or reverse at any speed.

 

[nvx1977]

Phantom screen touch has been an issue. EAsy way to diagnose is to launch the sketch pad and see if it gets anything on it without you touching.

I'd be too afraid to find 'REDRUM' on the screen the next morning.

 

[MP3Mike]

There is another factor which may apply in the X/S case. The chargers have the ability to control their output voltage/ current, and a PTC heater still has a power vs voltage curve, so it may be possible that the vehicle could leave the pack disconnected and run the heater at 1.44kW ish.

But the pack heater in the S&X isn't a PTC heater. (Only the cabin air heater is.)

 

[mongo]

But the pack heater in the S&X isn't a PTC heater. (Only the cabin air heater is.)

Ah, that works even better then (I was thinking working worst case with a low resistance PTC which would require a larger control voltage range than a straight resistance heater) so half voltage would be 1/4 power (interestingly, some 120V compatible hot tubs do the same thing, either 5kW or 1.25kW heater)

 

[mongo]

Well Tesla sells NEMA 6-20, NEMA 6-15, and NEMA 5-20 adapters so there are other cases, none of which can support a > 5kW heater load. Is there a range of temperature where that could matter? Yes. No charging at all is possible slightly above freezing (as a precaution for sensor variation and gradients within the pack). It turns out that temperatures right near freezing are quite common in the natural environment due to the heat of fusion of water, so getting just a little above that can make the difference between slow charging and no charging at all. A cabin with a 6-15 outlet where you're going to stay a few days the difference between no charging at all and 4 mph for 2 days could easily be a big deal. There are posts on TMC about not being able to charge at all in near freezing temperatures with modest (not minimal) EVSE.

As far as I know, neither the S nor X actually do this, although it might be theoretically possible. To be fair, I don't think the 3's software manages its "heater" very well yet either, but it is clearly feasible to do so; it is simply a matter of adding whatever desired amplitude (within power handling limits) drive in quadrature to the normal stator drive current. It can be done stopped, in forward or reverse at any speed.

In rereading the thread I realize I misattributed someone else's phrasing/ message to you, so was discussing somewhat orthagonally. I apologize for that.

I agree with you that an easily controllable heat source expands potential operating modes. More operation space is a good thing and will help some subset of people.

Also agree that the chargers/ SW may not be set up to perform that role (or become sub kW heat generators themselves). Seems like the S/X inverter would be able to do the same thing. If so, it would be a great feature to implement for the reasons you stated. Nice thing about SW updates.

Thanks for the discussion!

 

[wwu123]

Other things to check for: door(s) not completely closed (some have reported door seals are tight when new and doors need to be closed quite firmly); cabin pre-heat accidentally turned on. However, these are unlikely to be the issue. Probably best to consult service, as others have suggested. They will track it down.

I'm gonna vote for the door ajar theory. I've been out of town for three days, and my Model 3 in my garage is losing 3-5% of battery every night in relatively toasty 65 deg ambient. According to Teslafi, the car has been preconditioning for the last 72 hours, and the app says a door is open (probably just not closed tight). Can't lock or unlock the car, nor turn climate on or off (app says climate is off), due to "door is open". Quite annoying, will be close to 20% charge by the time we get back home.

I could see it losing a lot more charge outside on a cold night overnight in this situation.

 

[Electric700]

Perhaps contact [email protected]. They really should include a sound prompt / auto shut off after 12 hours. May be the Model 3 should also have Energy Saving / Always connected settings like the Model X and S do (with the default being Energy Saving On and Always connected off).

 

[llngoc]

Just FYI. As I posted in another thread, I am seeing 1 mile/hour drain parking at a commuter train station with outside temperature at about 50F. I am trying to switch off my logging apps and switched to my other Model X in the Tesla App to see if it will help.