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Settle an argument for me.....

Settle an argument for me.....

You have your TM3 plugged in - 240v Nema - you are NOT charging - you turn on the climate control to warm the cabin - is the energy you're using coming from the outlet or the car's battery?

Thanks.

Magic 8 Ball | January 19, 2019

Battery

gballant4570 | January 19, 2019

As M8B says, battery. If you want to use shore power, initiate a warming charge an hour before leaving. Then warm the cabin 10 minutes prior to leaving. My 20-21 mph level 2 charging rate drops to single digits (sometimes 0) while the cabin is warming, indicating the use of shore power.

Mike UpNorth | January 19, 2019

That's what I said - battery.

My uncle swears he read in the manual it would come from the wall.....I couldn't 100% say he was wrong.....

gballant4570 | January 19, 2019

The manual might speak to how far below your charge limit the battery power drops before the car initiates charging - but a 10 minute cabin warming won't use that much. In any case my experience reveals its the battery, unless charging is initiated first.

Mike UpNorth | January 19, 2019

He swears that he warms the cabin for 30 minutes in the morning, not charging, and the SOC doesn't go down.....I'm gonna call BS

gballant4570 | January 19, 2019

I have not been able to replicate that feat.....

Mike UpNorth | January 19, 2019

Agreed.

johnmann | January 19, 2019

The power for climate control comes from the wall when plugged in, not the battery. I have proof of this every time I preheat the car. I have a device that monitors energy use in our home. This morning the car had about 230 miles of range and I had the charging level set down at 50%. I preheated the car and immediately had an 8kw load appear in my energy app even though the car did not need charging.

Tesla2018 | January 19, 2019

I had my car plugged in and not charging and had the ac on and the lights on my charger that came with my car started scrolling after a while.

Maybe the plug in charger acts as a trickle charger if the 12V battery voltage drops too low?

Mike UpNorth | January 19, 2019

Whoa @johnman......

tigerkc | January 19, 2019

Power comes from the wall. I have done this numerous time:
- car was plugged in at work (chargepoint 220V @ 30A)
- car finished charging, car stopped drawing power
- turned on car heater before leaving work
- chargepoint showed car was drawing power from charger

Mike UpNorth | January 19, 2019

That's interesting @tiger.....Maybe you and @johnman proved me wrong....here's the only mention I could find in the manual page 98

Note: The climate control system is powered by the high voltage battery. Therefore, prolonged use
decreases driving range.

That seems like the battery not the wall to me but your experiences seem correct.....

Mike UpNorth | January 19, 2019

Then I found this on page 123-124:

Note: Whenever Model 3 is plugged in but not
actively charging, it draws energy from the
wall outlet instead of using energy stored in
the Battery. For example, if you are sitting in
Model 3 and using the touchscreen while
parked and plugged in, Model 3 draws energy
from the wall outlet instead of the Battery.

Damn - I think my Uncle was right and I was wrong....

jordanrichard | January 19, 2019

One doesn’t need to read the owners manual to get the answer. As soon as you turn on the climate control, you will see the “green eye” on the UMC moving and the “T” on the charge port flashing green. That tells you that it is coming from the wall, to power the climate control.

Mike UpNorth | January 19, 2019

@jordan

I wanted to try that out but wifey borrowed my TM3.

I guess it's settled.

kaffine | January 19, 2019

I comes from the wall. Look at the charging screen and it will show how much current is being pulled to run the climate control and number of miles being added as 0.

Now if you are plugged into a circuit that can't power all of the climate control it will pull from the battery as well.

beaver | January 19, 2019

My observation is that the climate pulls from the wall when plugged in but not charging. I see this on my dedicated meter and observe no drop in SOC.

But one issue with this mode is that I can pull power from Edison outside my charge schedule incurring higher per kWh cost. So just be aware, don’t run climate for hours outside your time of use cheap window.

jdcollins5 | January 20, 2019

I agree with @tigerkc. I installed a kWH meter on the breaker that feeds my 14-50. When I did an app preheat the power was coming through the kWH meter. Looking at the Charge Screen it showed 15/32A but 0 mph going to the battery.

kram | January 20, 2019

Wall , watch the amp number on the screen change when you activate Preheating/cooling.

SteveWin1 | January 20, 2019

Just because your car starts pulling power from the wall when HVAC is on, doesn't mean it isn't draining the battery with the HVAC while simultaneously charging the battery to keep the SOC stable. I know my cell phone works this way. I'm using it while plugged in right now, but the power isn't jumping straight from my charge cord to my screen. It's just keeping the battery at 100% as I drain it.

I'm not choosing sides... Just saying that you can't just look at how much juice your car is pulling and then jump straight to the conclusion that the power is skipping the battery.

wiboater4 | January 20, 2019

I 'd say you are both right according to what you read in the manual. It takes it from the wall BUT it also said if it's not already charging. . I'd like to see an option to use the battery for climate control so I could use the cheaper time of use price to heat my car when I'm only driving shorter trips etc.

howard | January 20, 2019

wiboater4, unplug after charging or prior to turning climate on.

wiboater4 | January 20, 2019

howard I have a detached garage and I charge overnight. I'd have to put on warm clothes and go out in the cold to do that. I know it would work but not worth the bother for me. I'm not a software developer but if it isn't hard the option would be nice to have. Key word is Option, not something everyone would be forced to use. The difference from off peak to on peak is 9 cents off and 20 cents on peak so not a large expense either way. my hours off peak are 8 am to 8 pm so if I was still working ( retired now) I'd still be heating the car on the cheap rate in the morning.

wiboater4 | January 20, 2019

One other think I'm in a cold climate so it's better to keep the car plugged in all the time.

SO | January 20, 2019

On my 2017 S, it starts with the battery but then within a minute or two, it pulls from the wall. It only pulls enough for the climate.

jdcollins5 | January 20, 2019

If I pre-heat while plugged in I do not lose any range miles. If I pre-heat without being plugged in a do lose range miles.

howard | January 20, 2019

wiboater4, there are a lot of options these days for WIFI or Bluetooth controlled power outlets/switches. Current rating would be key but switching the power remote should be doable.

howard | January 20, 2019

You might check with your power company. Here in CO they will install a smart savings controller for AC systems maybe that might work too.

abalsone | January 20, 2019

Not sure why this thread is so long looking for an answer. It’s simple to see. When you activate warming or cooling the wall charger contactors click and the “scrolling” green leds indicate power being sent to the car. The charging screen in the car says charging complete but still gives an amperage in use readout of how much power is being taken from the wall to run said climate control.

Ron.Olsberg | January 20, 2019

There are many things I still do not understand about when shore power is used and installing a power meter to monitor power usage would be helpful. When I open the drivers door, I hear the contactors close (connecting the HV traction battery to the buss) and for the purposes of the remainder of this post I am assuming they did NOT reopen or at least I did not hear them open . If the contactors DID reopen, everything would make perfect sense.

With the HV contactors closed, the traction battery, HV DC output side of the charger, and all other DC HV components are connected to the HV buss. If plugged into shore power, with the cabin heater on and the charger outputting a higher voltage than the traction battery (if it is?) why does there appear to be no current going to the traction battery? If you bring up the charging screen on the display while plugged into shore power, it shows amperage being used (apparently from shore power) when the heater is on but does not indicate that it is charging the traction battery? Maybe the onboard charger is smart enough to vary the HV DC voltage output to be lower than the current traction battery voltage so that no or very little current would flow into the traction battery? Since the cabin heater can pull significant current while active, using ALL of the available power and not charging the traction battery would make since. Is there another way, other than the HV contactors, to disconnect the traction battery from the HV buss and still have some/all the other HV components still on the buss?

Another mystery is why does topping off the 12V battery appear to NOT use shore power. When I hear the pump(s) running, sometimes for several hours, I assume the 12V battery is being topped off via the DC-to-DC converter. I am pretty sure the contactors are closed because when I open the drivers door or access the M3 via the phone app, I do no hear the contactors close. Seems like using shore power while the 12V battery is being topped off would be less wear and tear on the traction battery? It would hide Phantom drain because the 12V battery top off would not use the traction battery power but the KW use would still be there from shore power.usage.

wiboater4 | January 22, 2019

So was it a draw or did one of you concede defeat?

Mike UpNorth | January 22, 2019

Oh I conceded......Def he was right and I was wrong.....Pretty lame as he's never been on the Forum and I'm a rat.

But then again even M8B was wrong so that makes me feel a little better :)

12Brent | January 22, 2019

Put me in the, "it takes it from the wall" group. I preheat every morning here in Colorado and when I go out to my car the UMC is pulsing green, the charging screen shows current being drawn, and the range is the same as it was when I started the preheat. If you are outside of the scheduled charging window (if you use scheduled charging) it might behave differently and use the battery, but I don't know for sure.

Magic 8 Ball | January 22, 2019

Really power does not go from wall to battery to car accessories? Is there an actual converter that takes the AC wall power and sends power to the accessories while bypassing the battery? While the battery may not be technically charging could it not be just large capacitor when used in that mode I describe?

12Brent | January 22, 2019

I think the spirit of the post is where does the net energy come from. If the car battery state of charge stays the same then ultimately the energy for the climate control is coming from the wall. I'm not going to get caught up in semantics. If I want to do that I'll argue with my 12-year old who knows everything.

TM3Q | January 22, 2019

When plug into Tesla wall charger (240Vac 48amps max) even if not charging the car, it draws current from the wall if you enter the car or activate the climate control via app.

If you have battery discharging during climate ON while plugged this means you don't have enough power drawn from the wall like per example plug into a 110Vac outlet witch is set to draw maximum 12 amps (1,32kW), so clearly the battery will compensate for the required power.

Magic 8 Ball | January 22, 2019

Semantics, eh? The question specifically asked if the energy comes from the wall or battery for climate control. Obviously all the energy for the car comes from the wall so the question is all about semantics. I have seen no evidence that energy is supplied to the climate control from some bypass that converts the wall power to directly power the climate control apart from the battery. I doubt that if you took that battery out of the car that you would be able to power climate control by plugging into the wall. I could be wrong but I believe the power still comes from the battery in a sense the battery may be a passive element in the circuit at times but is essential in running climate control.

kevin_rf | January 22, 2019

No reason it can not be pulling directly from the wall. It knows how much current the sub systems are drawing and should match the output from the AC to DC converter. Both the battery and DC converter should feed the same HV bus that the sub systems are drawing from.

All I know is the angry green tesla alien mounted on the wall in my garage starts pulsing green when ever the car is awake and drawing power.

Mike UpNorth | January 22, 2019

@M8B

I meant it as a compliment......but you were wrong and you know it....just as I was. And @GB

Magic 8 Ball | January 22, 2019

Nope, I don't know if I am wrong. I admit I do not know for sure but I have not heard anyone say the climate control will work with battery removed from the car.

TM3Q | January 22, 2019

The battery is made of thousand small lithium battery wich is direct current (dc) power source.

The battery charger inboard output is direct current in order to recharge the battery. The charger needs dc to charge in dc so if you have an ac external power source then you convert ac power to dc power in order to recharge.

So the battery charger input can get it's power source from alternative current (ac) or direct currect (dc) that's why you have the choice to either plug at your house wall with 120Vac or 240Vac and for faster and direct charging at a supercharger wich delivers dc power.

The question is: Why using the car battery to power up the car when you have external source that can deliver the needed power? Better to keep the car battery resting without any charging and discharging when not necessary needed.

Mike UpNorth | January 22, 2019

Lol, okay

Mike UpNorth | January 22, 2019

I'm pretty sure my cell phone would power on and work without a battery inside but plugged in.....same thing or no?

Magic 8 Ball | January 22, 2019

Why use the car battery instead of external source? Could be one design is simpler than the other. The key is the bus architecture and I have not heard anyone describe how the onboard charger/controller powers an HV bus that powers the HVAC and charges the battery separately.

kevin_rf | January 22, 2019

Also worth noting, for safety, the battery needs the ability to disconnect, or be disconnected from the HV bus that powers everything.

There have been a couple of cases when the fuse between the battery and the car have blown leading to car becoming a brick flying down the highway. In those cases the electronics that run many of the critical sub-systems kept work (doubt heat was one of them). Most likely powered off of the weird little 12v battery the Model 3 has.

This leaves no reason for the car not to be able to isolate the battery and pull entirely off of the charger.

The Prius did something similar by powering the DC converter off of it's 12v. Dead 12v, dead car.

kcheng | January 22, 2019

@Mike, you've been 8balled. Welcome to the club. Don't worry about it, he likes to argue over minutiae and get the last word in.

Magic 8 Ball | January 23, 2019

Look like the creep is still stalking me.

CorkChop | January 23, 2019

SHORE POWER not the battery. From the manual, page 123-124:

Whenever Model 3 is plugged in but not
actively charging, it draws energy from the
wall outlet instead of using energy stored in
the Battery. For example, if you are sitting in
Charging Instructions
Charging 123
Model 3 and using the touchscreen while
parked and plugged in, Model 3 draws energy
from the wall outlet instead of the Battery.

Magic 8 Ball | January 23, 2019

Manual is wrong!

Can I change my answer? (insert embarrassed emoji here)

Mike UpNorth | January 23, 2019

lol Finally!

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