Rivian Preheating for Planned Drives - Does NOT Precondition The Battery (Update it does if plugged in?)

[MountainBikeDude]

My Vehicle doesn't reliably warm the battery when plugged in with preconditioning scheduled. Perhaps if warming the cabin drains the battery enough that it needs to recharge the battery, then it will warm the battery so that it can charge. But just being plugged in doesn't change anything.

I have occasionally seen preconditioning do as I expected, but it doesn't most of the time. I haven't yet figured out when it will and will not work.

The feature (or the description of it) clearly still needs work.

It preconditions the battery and drivetrain for efficient driving, not efficient fast charging during your drive. The point of it is to ensure you have both power and regen levels without limits imposed once setting out.

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It preconditions the battery and drivetrain for efficient driving,

That's not what I'm experiencing. Most of the time it's not preconditioning the battery at all.

This morning when I pulled out of the garage after preconditioning with the vehicle plugged in the battery was less than 30°f and the vehicle was complaining about it being too cold to perform well.

It does occasionally precondition the battery, but most of the time it doesn't. And it doesn't seem like anyone has figured out how to tell when it will and will not precondition.

 

[kurtlikevonnegut]

In theory the car is way more efficient when the battery is preheated, right?

If I can spend 5 - 10 kwhs up front to get that, and presume it takes 20 minutes to heat up the battery otherwise. With a cold battery I get 1 mi/kwh with a warm battery I get 1.5/1.6 most times.

This means that on highway driving going 80 miles per hour, I'd dome like 25/30 miles and it'd use 15 kwhs. That'd save me 15 kwhs, when I only needed to spend 10 kwhs. Thus saving me energy. All of that is assumption based, because we don't have data because it isn't an option. Other brands offer this feature while on battery because I would assume it's more efficient as well.

The efficiency gain while driving is offset by the energy you use to condition the battery since you are using battery power. The truck has to expend battery power to perform the conditioning when it's not plugged in, so I don't see the net gain.

Again, I don't know the exact physics involved, but it seems any gain would be negligible.

 

[MountainBikeDude]

That's not what I'm experiencing. Most of the time it's not preconditioning the battery at all.

This morning when I pulled out of the garage after preconditioning with the vehicle plugged in the battery was less than 30°f and the vehicle was complaining about it being too cold to perform well.

It does occasionally precondition the battery, but most of the time it doesn't. And it doesn't seem like anyone has figured out how to tell when it will and will not precondition.

Interesting... I don't have a charger at my apartment, so I can't attest to the charger/no charger variable, but without a charger connected when my vehicle was in -3 celcius overnight, it did its preconditioning for around 35 minutes prior to me setting out that morning. I didn't have any limitations that morning, so in my case it completed the objective, despite the battery still only being around +6 celcius when getting in.

I did however, turn off the preconditioning, because my regen etc limitations in that weather, aren't enough to justify robbing the battery for half an hour just for some minor performance boosts at the start. I'm likely still using a similar amount of power, or close to by just driving cold to the destination inefficiently, as I would preconditioning, then setting out.

I want to try it out at our house to see the difference while plugged in to the charger, but that experiment will have to wait a bit.

 

[MountainBikeDude]

The efficiency gain while driving is offset by the energy you use to condition the battery since you are using battery power. The truck has to expend battery power to perform the conditioning when it's not plugged in, so I don't see the net gain.

Again, I don't know the exact physics involved, but it seems any gain would be negligible.

I had the same impression.

 

[Millertimr]

I also thought preconditioning was better for the long-term health of the battery as opposed to using it when it's cold.

It is indeed, it's not great to run on a 17 Fahrenheit battery I imagine.

 

[Millertimr]

I had the same impression.

So some peoplee want battery preconditioning, some people do now. why not ultimately give the user the decision to decide whether they want to use battery preconditioning or not? Considering other major automakers offer it as well as an option supposedly because people use it. I just find it weird.

 

[iansriv]

A few years ago I asked a well respected gent to explain MBS and CDOs and I understood just as little after the explanation as I had before it. Then the financial crisis hit and it became evident no one understood anything about these.

After spending more time than I should on this board I've come to the conclusion that most of the people here are very intelligent. However, it appears that we don't have a clear understanding of what the car is supposed to do for pre-heating and pre-conditioning. It shouldn't be this difficult. Rivian should make this more intuitive. The app and car should give you the clear indication of what you are heating up-the cabin or the battery or both.

 

[AllInev]

@OutofSpecKyle Do your job and settle this!!! ?

 

[Singletracker]

Well, it’s 10:15 pm and I‘m going skiing tomorrow morning. Right now, I’m going to go out and plug my truck in. Tomorrow, about 1/2 hour before I leave, I’m going to manually, from the app, start a brief charge session and cabin warm up. It may not be 50.01 automatic, but it usually does the trick for maximizing efficiency

 

[Franksmartin]

the email from Rivian says specifically that you need to be plugged in to precondition the battery. However it’s not working for me - batter was 30 degrees after a scheduled warmup and plugged.

 

[Greg Chick]

I guess is that the pre heat will only happen if the battery is out of the temp. window that is required to charge well. So when the battery is not too hot or cold, why spend energy to change it just to save energy plugged in or not!
So the Service Tech may be right, but just failed to say that "when needed" it does or does not do this or that.

 

[Autolycus]

So some peoplee want battery preconditioning, some people do now. why not ultimately give the user the decision to decide whether they want to use battery preconditioning or not? Considering other major automakers offer it as well as an option supposedly because people use it. I just find it weird.

I don't know the math on Rivian's particular setup, but why would you find it weird if Rivian doesn't allow the user to select an option that Rivian has determined through testing and knowledge of the technical specifications of their entire system is less efficient and wasteful of energy for no benefit?

 

[Herb]

I still don't understand the issue here. Why do you want to use battery power to condition the battery? What is the supposed benefit?

I am not an expert, but I would assume that using friction generated from motion would be a more efficient method of heating the battery than using battery power when stationary. Even if not, I can't imagine the benefit is significant.

There's a theory that pre-conditioning the battery returns better efficiency (m/kWh) and the investment of pre-condtions pays enough dividends to come out ahead. On my drives, I have no evidence, at best it could be a wash under the right conditions, but then you would have the benefit of a warm cabin. The battery itself does not have a heater. They run a current through stationary drive motors and warm coolant is pumped into the battery cooling/heating loop.

 

[DRIVIAN]

I'm on Version 2023.50.01 in a 2023 R1T and using Android App version 2.5.1 on a Pixel 8 Pro phone. Sometimes preconditioning works and sometimes it doesn't. I've only attempted it while plugged in, so that's not the issue. I thought maybe it was only working when I set the schedule on the dash instead of the app. Now, after reading this, I'm not sure. It is frustrating to leave the house early in the morning on a day when it's 8 degrees, and have anticipated a preconditioned battery, only to find the battery is 37 degrees. I'm curious if others who've had trouble are using the app or the in-vehicle interface.

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