To precondition or not?

[sleepydoc]

It’ll be a few months before this is relevant, but does anyone know (or has anyone tested) whether you’re better off warming up and preconditioning your car vs just getting in and driving it in the wintertime when it’s not plugged in?

Preconditioning the car from the app warms up the cabin but also warms up the battery so while it uses energy, it also increases efficiency by allowing regenerative braking. My question is whether it’s worth the trade off (and how to decide when it is.)

 

[240vPlug]

If your doing it just for regen and your unplugged it isn’t worth it. If your preconditioning for comfort that is subjective.

If your plugged in it’s probably a good idea to precondition especially if your going on a longer trip/commute.

 

[ATPMSD]

My view, for what‘s it worth.

If you want to warm / cool the car just use the app and turn on HVAC about 5-minutes before you head out. BTW, this also starts warming the battery, if needed.

As to preconditioning the battery, if the battery is not warm enough two things happen until the battery warms-up:

• Your acceleration is limited, you can’t floor it, but it is still plenty quick
• Regenerative breaking is limtied. As long as you are aware of this, which is shown on the display, this is not an issue. I believe the power consumed to warm the battery is more than what is not added when regen is limited.

I never use preconditioning.

 

[jcanoe]

From a cost standpoint it depends on whether you are able to charge your Tesla Model Y at work or at a public charging station at no cost to you. If you can charge at work then it makes sense to minimize the amount of charging you do at home, this includes preconditioning while the Tesla Model Y is plugged in. When you plug in and charge at home the cost of preconditioning for 10 minutes is minimal, perhaps $0.15. The benefits include: safety (defrosting the windshield and other glass) and driver and passenger comfort. For short trips of less than ~20 minutes preconditioning will improve the driving efficiency, lower your Wh/mile. When preconditioning the battery will be warmed so that you will have some regenerative braking when you drive unless the battery has been charged to over 85% to 90% in winter. If the battery state of charge is high then regenerative braking may not be available.

 

[Mateo83]

I haven't seen the need in California. But I'm also parked in my garage when charging.

 

[Geir]

Preheating battery Model 3 RWD. When you select a supercharger and drive towards it, preheating of the battery starts. As I understand it, this is done to get faster charging. But I think it is not good for the battery with high power (when one is not in a hurry). Could it be better not to let the car preheat the battery? Energy is used for storage as well. The preheating can last for a very long time, I have noticed. This is lost energy. The charging effect will adapt to the battery temperature, right?

 

[jcanoe]

Preheating battery Model 3 RWD. When you select a supercharger and drive towards it, preheating of the battery starts. As I understand it, this is done to get faster charging. But I think it is not good for the battery with high power (when one is not in a hurry). Could it be better not to let the car preheat the battery? Energy is used for storage as well. The preheating can last for a very long time, I have noticed. This is lost energy. The charging effect will adapt to the battery temperature, right?

The power used to generate heat via the drive unit electric motor stator is not that much, i.e. 3.5kW per motor. The long term effect on the health of the of motor stator is unknown but Tesla has probably considered this when programming the stator warming.

If you don't precondition before Supercharging then you won't be able to charge at the maximum output level of the Supercharger, perhaps only half of the maximum. The charging session will be slightly less efficient at lower kW charging rate as the battery will not be at the optimal temperature for Supercharging and because it will take more time for the battery to reach the same state of charge, i.e. ~80% before ending the charging session.,Still, if time is not a factor you can take a little more time to charge with no downside other than your Tesla vehicle occupying the Supercharger stall (something Tesla tries to minimize.)

Charging at 1 X C (where C is the capacity of the battery) is less stressful than charging at 2 X C or 2.5 X C. Tesla has considered this and closely monitors the age, health and state of the battery during the Supercharging session. Still, frequent use of a Supercharger will have a cumulative affect on the long term health of the battery. Charging at no more than 1 X C will be less stressful if you have the time. (Urban Superchargers are limited to about 1 X C so even with preconditioning the Supercharger session at an Urban Supercharger (these are typically found in parking garages where space for the behind the green curtain Supercharging equipment is limited) will be limited to 72kW.)

 

[GtiMart]

If it's cold enough, power will be limited enough that you won't find it "plenty quick" @ATPMSD . On days at -20C or lower if I don't precondition I get only ~100hp, a Prius could pass me That is on a LR AWD+Boost... Since the car reduces power, I don't believe I'm hurting the battery in any way, it's just less fun to drive. Obviously at that temperature there is no regen at all.
A couple years ago battery warming was relatively "aggressive" and wouldn't stop until the battery reached around 20C. That was a lot of energy spent. For short trips it made absolutely no sense. Since last winter this was adjusted and I believe the target was around 5-7C before the motors would stop spending energy. You get a good chunk of regen at those temperatures now.

The relative consensus around here is that preconditioning will not give you back more energy in efficiency than the energy you spent. Unplugged, it would not be worth it just for energy consumption. For a short trip, it's clearly not worth it. For your own comfort, you can choose to precondition a couple minutes before you hop in. For longer trips it might be worth it just to raise your chances that the battery can warm in time for the next supercharging session... That is especially true for SR+/RWD who have a single motor to generate heat and drive the car. In winter these can have trouble preconditioning, even 1 hour or more in advance. I mean in real cold areas...
If you prefer to have regen, then precondition.

 

[GtiMart]

OH, I forgot to add one comment about supercharging... if you don't precondition, or precondition but not long enough, your car will heat the battery as you charge. Part of the energy you receive (3.5kW in your RWD case) will be used to heat the battery, You won't escape it, the car will do it. So you'll have slow charging AND you'll pay for the heat anyway. Might as well precondition while you're going there.

 

[TeamRedM3]

Noob to the Tesla world (just into my first month with my M3RWD) and want to understand the "predonditionning" question...so here goes.
I understand the "preconditioning" of the battery as I'm driving towards a SC, i.e. prepare/heat the battery for the "charge" it will receive.

At home I'm parked in a 2nd level undergroung spot and plugged in.

So the question is: if I need to go out around 10am, do I need to do anything?
My understanding is, and this is were I would appreciate clarification, I can start the HVAC prior to departing to get the car comfy for the passengers which also "heats up" the battery. But seeing were I'm parked my car is always "comfy". So do i HAVE to turn on the HVAC for the sole purpose of "heatng" the battery? Or do I just drive off.

Lastly, should I adopt the same behaviour all year long?

Hope my question is clear?

Thanks in advance for any responses.

 

[GtiMart]

You can ALWAYS just hop in and drive off. It's just a car, it will work. As a bonus, it will "always start" whatever the temperature, and you should get some heat within 30sec-1min in the cabin.

When the battery is too cold, you will get little or no regen. In a recent software update you can optionally tell the car to use the friction brakes in that case so you won't even feel the difference. Otherwise it's just an adjustment, you need to use the brake pedal more.
By preconditioning the cabin, you'll arrive to a more comfortable car and you will have some regen. Don't count on this to save you energy overall.

What you do depends on you, there is no one single good answer.

 

[sleepydoc]

If you’re parked in an underground garage your car will likely never be terribly cold And not cold enough to affect regenerative braking significantly.. like @GtiMart says, you can always just drive the car. If it’s cold enough to affect regenerative braking you’ll see some dots on the left side of the power bar And may get a notification.

preconditioning for supercharging is to get the battery at optimal temperature for charging to allow the maximum charge rate. That minimized the time you spend supercharging which is a convenience to you and opens up the SC space sooner. You can supercharge without preconditioning; the car will adjust the charge rate for you based on the battery.

 

[jcanoe]

Noob to the Tesla world (just into my first month with my M3RWD) and want to understand the "predonditionning" question...so here goes.
I understand the "preconditioning" of the battery as I'm driving towards a SC, i.e. prepare/heat the battery for the "charge" it will receive.

At home I'm parked in a 2nd level undergroung spot and plugged in.

So the question is: if I need to go out around 10am, do I need to do anything?
My understanding is, and this is were I would appreciate clarification, I can start the HVAC prior to departing to get the car comfy for the passengers which also "heats up" the battery. But seeing were I'm parked my car is always "comfy". So do i HAVE to turn on the HVAC for the sole purpose of "heatng" the battery? Or do I just drive off.

Lastly, should I adopt the same behaviour all year long?

Hope my question is clear?

Thanks in advance for any responses.

You don't have to precondition before leaving in the A.M. but doing so has some benefits, even if you only precondition for ~10 minutes.

Preconditioning for Supercharging is a special form of preconditioning, only happens while driving when using the Navigation system to navigate to a Supercharger. Standard preconditioning takes place while the Tesla Model Y is parked, whether plugged in or not.

You may be comfy at 10C or 15C but the Tesla battery is not at full operating temperature until ~21C. Regenerative braking will be reduced whenever the battery is not fully warmed. (You can now enable friction braking to compensate for the reduced regenerative braking so the Tesla Model Y will slow accordingly when you release pressure on the accelerator pedal.)

By warming up the passenger cabin before driving the heat pump will not need to work as hard once you set off driving. This will improve your driving efficiency and range, especially for short trips of under ~20 minutes.

You can set the heated steering wheel and heated seats to come on automatically while preconditioning, turn the climate control down to a lower temperature if you wish and still be comfortable.

The Tesla Model Y's climate control system will warm and dehumidify the passenger cabin, this will help keep the inside of the windows from fogging.

Experiment by setting a Departure Time for Monday through Friday of 10:00 A.M. and then decide if you would prefer to precondition manually using the Tesla app or not at all.

Preconditioning is arguably more useful in winter as this will warm the passenger cabin and partially warm the battery. In summer preconditioning for even just a couple of minutes means not getting blasted in the face with warm stale air as you enter the Tesla Model Y.