Cold weather checklist: Advantage to keeping vehicle plugged in?

[hobbyjogger71]

geez….is not overly ambiguous. It is common knowledge that EVs suffer from “phantom drain”, which is more particularly pronounced in the extreme cold…..so even if you are not actively charging, if your battery drops below the set point, it will start to charge again, and warm the battery to some degree.
Additionally, if you are in the habit of warming up your vehicle before departing, and it is plugged in, the HVAC will pull from the charger rather than the vehicle, and the battery is warmed as well (neither of which occur if you heat the vehicle and it is not plugged in).

Per the hot thread in this sub-forums, "The Preconditioning Myth" - I don't think any of that last statement is true, or at least with the definitive truth you speak. I have never seen my Emporia charger report power being pulled unless the car is below the trigger and charges up to meet it.

The truck never pulls shore power - it's the battery that is then topped off. That setting is only giving it permission to top off should you be outside of a charge window (for TOU reasons).

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[Singletracker]

I am just joining this message so forgive any repeat but Beatle, doesn’t the car have to have “some” command to charge?? My understanding is you can have the charger plugged in but NOTHING happens until you give it a command like the charging limits set? If you have 85% set as a limit, once it goes below 85% it will start charging automatically to keep it at 85%. If you have 40% set, it wont charge until it goes below 40%. The schedule is a different issue just to save money. I guess Rivian could have said in its instructions “per the limits you set” to make it more palatable.

Exactly my point! My car was plugged all night, but not set to charge. My charging schedule was not activated. My set battery limit was well above the actual battery state. Did the car decide to charge up to the set limit? NO. Did the battery condition and stay warm? Not as far as I can tell. Actually, there are two different issues here - maintaining a set level of charge and keeping the battery conditioned. The just plug in and go plan works only if the charging option is activated, either with the app or in the vehicle. After that, the car will control the charging activity to maintain the battery capacity at the owner‘s set level. I’m not sure how this actually affects the battery conditioning, however. For that matter, what the heck is the actual criteria for a conditioned battery?

I’ve had my Rivian for a year and a half ( my first EV). In that time, I have learned a ton. I probably know a little more than a lot of people about how it functions, but there are whole lot of folks that know a whole lot more than me. That is for sure! Hanging out in this forum one can learn a lot. However, at times the info is conflicting and, clearly, people are perceiving different things and reporting different things as fact. It can be hard to get to the truth. For those that are new to EV’s or aren’t tech nerds, explaining processes more completely and clearly can make a difference. IMHO, for example, just saying “plugged in“ doesn’t tell the whole story. Simple statements like ”keep it plugged in” assume that novices will automatically understand what is happening. I wish that Rivian would publish some more info on how these systems work and relate to one another.

 

[Singletracker]

If the goal is to keep the battery somewhat preconditioned, not necessarily at any preset state of charge, how about this plan? Say that my battery is sitting at a 70% charge level, I am not concerned with maintaining that level of charge, and my only concern is keeping the battery happy. I could set my desired state of charge say at 40%, plug it in and make sure the car is set to charge. Of course, it won’t charge as the preset level is too low. Question is - will the car, in an attempt to keep the battery conditioned and happy, randomly draw any necessary power to accomplish that goal?

 

[hobbyjogger71]

If the goal is to keep the battery somewhat preconditioned, not necessarily at any preset state of charge, how about this plan? Say that my battery is sitting at a 70% charge level, I am not concerned with maintaining that level of charge, and my only concern is keeping the battery happy. I could set the my desired state of charge say at 40%, plug it in and make sure the car is set to charge. Of course, it won’t charge as the preset level is too low. Question is - will the car, in an attempt to keep the battery conditioned and happy, randomly draw any necessary power to accomplish that goal?

From what I know and understand, I highly doubt it. Well not until your vampire drain pulls you below 40%.

 

[Singletracker]

From what I know and understand, I highly doubt it. Well not until your vampire drain pulls you below 40%.

Keep it plugged in. Keeping the vehicle plugged in when it's parked helps with battery temperature and improves preconditioning efficiency. - Rivian.

This statement from Rivian does not say that the car needs to be charging and this whole process is dependent on keeping the battery state of charge at some random preset level. If my preset state charge level is below the current battery state of charge, keeping it plugged in probably does nothing to help “battery temperature or improves preconditioning efficiency.“

Anyway, I’m trying it right now. Preset my limit to 50% (that’s as low as it would go). Battery is at 58% and 37º. I could not initiate charging, as the preset is below the battery state. So, don’t know what is going to happen with the battery condition, if anything.

Here’s an interesting observation. Normally, when charging is disabled the light around the plug is off. Although, on the app, I was unable to initiate charging, the light around the plug is now green. Maybe something is happening related to battery conditioning, or maybe it is just in standby mode waiting until it gets down below 50%.

 

[Captain JB]

The lamp example is good but how about a toaster which is a very high draw item……if it is plugged in all week, no current or voltage will be applied until it is turned on (given a command) JB

 

[Doc]

Keep it plugged in. Keeping the vehicle plugged in when it's parked helps with battery temperature and improves preconditioning efficiency. - Rivian.

This statement from Rivian does not say that the car needs to be charging and this whole process is dependent on keeping the battery state of charge at some random preset level. If my preset state charge level is below the current battery state of charge, keeping it plugged in probably does nothing to help “battery temperature or improves preconditioning efficiency.“

Anyway, I’m trying it right now. Preset my limit to 50% (that’s as low as it would go). Battery is at 58% and 37º. I could not initiate charging, as the preset is below the battery state. So, don’t know what is going to happen with the battery condition, if anything.

This is from @cmerritt408. It does a good job explaining what's causing the vampire drain on the main battery and how it can be stopped/reduced. Video takes a few minutes but there is a "TLDR summary" for those who don't want to view. Basically, keeping the vehicle plugged in will keep the SOC from dropping below your preset level.

TLDR: The root problem is that the 12v battery is vastly undersized, in combination with the Gen1 electrical design requiring the Rivian's computers to be fired up to run the High Voltage -> 12v recharger, and those computers then eat around 300w of power. This is why you see 1-2% SOC loss per day when your R1 is unplugged, it's the 12v discharge/recharge cycle that's killing it.

Nifty graph from Electrafi merged with DC datalogger output showing how the R1's puny 12v battery cycles over 24 hours:


Several ways to fix it then described in the video above:

• Hook up a 12v battery tender, and boom your R1 will basically never wake up (without otherwise being perturbed)
• If you're on the move off the grid, a battery tender + supplemental 'camp' battery does the same.
• If you're off the grid but mostly stationary, add solar to feed the camp battery system indefinitely.
• Also, vampire drain is reduced by approximately 1/3rd by upgrading to an Ohmmu 12v LFP battery, delivering more time between charge cycles and also faster recharging than the OEM lead-acid AGM 12v battery.

And then lastly, beyond vampire drain, how can you help keep your R1 asleep when off the grid?

Turn off the AC, turn off proximity locking, put it into camp mode (power 'off' of course), and then be mindful about opening and closing doors. Opening any door wakes a Rivian up, as does closing (most) of them, and then it takes 5-10 minutes generally to fall back asleep.

LEAVING doors or windows open is just fine, it's the state change from closed to open or vise versa that does the damage.

ps, this caps off a series of videos on improving Rivian efficiency:
The AC Inverter - Forged Wheels - Aerodynamics (RTT vs. R1T)

 

[webfootdawg]

Sitting at home, jammies on, sipping my adult beverage on a cold winter evening. Haven't driven the Rivian in a few days, since I bike to work, but I leave it plugged in.
SWMBO. "Do you want to go skiing tomorrow?"
Me. "Sure."
Reach down to phone, open Rivian app. Change state of charge goal from my daily setting to the level needed for round trip to the mountain. Take another sip of beverage and smile.

 

[No_Name5330]

I think the OP has a serous case of overthinking.
What does plugged in mean exactly?

 

[Singletracker]

Sitting at home, jammies on, sipping my adult beverage on a cold winter evening. Haven't driven the Rivian in a few days, since I bike to work, but I leave it plugged in.
SWMBO. "Do you want to go skiing tomorrow?"
Me. "Sure."
Reach down to phone, open Rivian app. Change state of charge goal from my daily setting to the level needed for round trip to the mountain. Take another sip of beverage and smile.

Yes. Love my Rivian. And, yes, I want to go skiing. Can you please send some of that snow my way? We could really use it down here.

 

[Singletracker]

I think the OP has a serous case of overthinking.
What does plugged in mean exactly?

Guess it’s better than not thinking, at all. See ya ??

 

[No_Name5330]

Guess it’s better than not thinking, at all. See ya ??

Sorry I figured my post would be taken with a grain of salt, but clearly it wasn’t and someone’s just having a bad day.
When i saw the phrase “plugged in”, i didn’t stop to overanalyze whether it meant actively charging or just being connected. I assumed it simply meant having the EVSE plugged into the car, letting the system manage itself based on battery temperature and SOC, because let’s be honest plugged in isn’t that complicated. As others have said, a toaster is plugged in even if it’s not toasting, same with a wireless charger even if it’s not charging a phone.

From experience, Rivian keeps their newsletters pretty straightforward, and honestly, its not worth overthinking something designed for the average owner who just wants to get from point A to point B. Lets face it, most of us on this forum are far more informed than the typical Rivian owner who might be treating that email like breaking news.
Good day?

 

[VSG]

My car was plugged all night, but not set to charge. My charging schedule was not activated. My set battery limit was well above the actual battery state. Did the car decide to charge up to the set limit? NO.

I don't understand this statement, and I don't know what you mean by "not set to charge". If you car is plugged in and the charge limit (set in the car or through the app) is "well above" the current battery state, then the car should have started to charge automatically and immediately. There is no "on" switch for charging like with a lamp - it will automatically start charging.

I guess what you describe could happen if you have settings on your charger that restrict the time of day it can be used or something like that, but otherwise your car should just start charging. There is no button that needs to be pressed to initiate charging.

 

[Singletracker]

I don't understand this statement, and I don't know what you mean by "not set to charge". If you car is plugged in and the charge limit (set in the car or through the app) is "well above" the current battery state, then the car should have started to charge automatically and immediately. There is no "on" switch for charging like with a lamp - it will automatically start charging.

I guess what you describe could happen if you have settings on your charger that restrict the time of day it can be used or something like that, but otherwise your car should just start charging. There is no button that needs to be pressed to initiate charging.

This button in the app can be used to turn charging on and off regardless of any charging limits or HVB state of charge. This could also be done in the car. Often, I will come home in the afternoon and, knowing I’m not going back out for the day, I will plug the car in, but turn the charging off. I do not want it charging during peak usage/high rate hours. I figure I can always fire it up from the app, if need be. I may not start it up again until the next day. It’s just more convenient to not have to go out in the cold to plug it in when I need it. In a scenario such as this, when charging is turned off, I was curious if the battery was still being conditioned or not. And, yes. I do schedule TOU charging at times, but not always. I would like to think otherwise, but it’s becoming fairly clear that, when the car is not actively charging, having it plugged in has no effect on battery conditioning.

 

[VSG]

OK I understand now. Your use case is to plug in (which does start the car charging immediately, right?) but then you immediately and deliberately turn off the charging using the button on the app.

I think if you explicitly turn off the charging, like you do, it will stay off until you explicitly tell it otherwise.

But if you DON'T turn off the charging, then the vehicle will charge when it needs to charge, subject to any time-of-use schedule you have set.

The only time I turn off charging is when I'm ready to pull the plug out. And these days I use the button on the J1772 plug to terminate the charging - press the button, charging will stop, then you can pull out the plug. When DC fast charging I always terminate charging from the center screen or from the charger itself.

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