8 nights unplugged in cold weather, shipping mode _results

[Rivian Rider]

After my previous post about extreme battery drain while parked and unplugged, where I asked about 4-5% overnight drain and was worried about leaving the car at the airport, I finally tested leaving it for 8 nights in a New York (cold weather) garage. Here's what happened:

[i have a dual motor, standard battery, 2026 R1S]

I fully charged the car to 100% at a nearby supercharger and drove it to a public coveted garage. I arrived with 97% charge which equalled 267 miles. (By the way, this is the only time that I supercharged to 100%, and the only time that 100% equalled 270 miles. Normally 100% equals 250 miles when I charge at home).

At the garage, I turned off Wi-Fi, gear guard, climate, even incident cam, and the interior camera (just for the hell of it). Then I put the car in shipping mode and locked and left. Finally, I even logged out of my Rivian app and swiped it closed. For OCD reasons, I even removed all the Rivian widgets from my phone.

While away, I did not open the app to check anything. Knowing it would not have mattered.

Eight days later, when I got back, I opened the app and checked the mileage from a location near the garage. First of all, the app could connect to the car. I was told that once in shipping mode, the car is not in communication anymore. That is not the case. The app showed that the battery was down to 88% or 191 miles. Phew, that was good.

I got to the car and got in, the charge had dropped to 84% or 184 miles just in half an hour. Which meant that just opening the app and waking the car up had quite an impact.

so overall, I lost 13% or 83 miles. The percentage drop was 1.62% per night. In shipping mode.

Now, I wonder if the extreme overnight drain that I had experienced in the past was really just for the first night. And that it tapers down.

I also wonder if the shipping mode did not have much of an effect, but rather not waking the car was what mattered most.

Anyway, hope this is helpful for some.

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[sherold]

It would be interesting to know what the actual temperatures at the vehicle were during that time. That can have a substantial impact on the amount of drain. Once the pack reaches ≈14°F, the battery energy is used to heat the battery and keep it from being damaged. That action would have quite the impact on energy usage.

 

[Vik]

How much of this is vampire drain vs. LFP pack balancing?

 

[PhiltheCasual]

83 miles lost is 30% of 270, no? I'm a bit confused about the 13% lost metric.

 

[Rivian Rider]

Yes that is confusing. The percentage displayed shows a 13% loss but the range displayed shows an 83 mi loss. Rivian explains this but claiming that the mileage can go up and down based on weather conditions (that in warmer weather, 13% loss would equate to less miles). I frankly don't get this and find it confusing that their percentage and range don't correlate. Maybe someone else can explain this.

 

[Rivian Rider]

How much of this is vampire drain vs. LFP pack balancing?

I couldn't tell you. Feels like you need an advanced degree in battery management to know what is going on with the LFP battery

 

[Rivian Rider]

It would be interesting to know what the actual temperatures at the vehicle were during that time. That can have a substantial impact on the amount of drain. Once the pack reaches ≈14°F, the battery energy is used to heat the battery and keep it from being damaged. That action would have quite the impact on energy usage.

I know it was a cold week.

 

[COdogman]

Good thing you turned off Gear Guard so you didn't have to see the garage urinators.

 

[beatle]

Yes that is confusing. The percentage displayed shows a 13% loss but the range displayed shows an 83 mi loss. Rivian explains this but claiming that the mileage can go up and down based on weather conditions (that in warmer weather, 13% loss would equate to less miles). I frankly don't get this and find it confusing that their percentage and range don't correlate. Maybe someone else can explain this.

Probably because the overall capacity of the battery drops as it gets cold. Looking at ElectraFi status, my truck swings between 135-143 kwh depending on temperature, and my SoC can actually go up in some of those cold swings. The energy available goes down a bit, but it is from a battery that the truck thinks has lower capacity since it is cold. As you drive the truck and it warms the battery back up, you'll see your SoC plummet super quick since the battery "grows" in capacity when it returns to a more normal temperature, in addition to the initial heavy HVAC and battery heater load.

I charge to 85% daily, so that's 121.55kwh in a 143kwh pack.
When temps are low, that same 121.55kwh is 90% of a 135kwh pack. I've never seen my SoC go up 5%, but it has ticked up over a percentage point over the course of a day, and kept it over 85%, even with the usual vampire drain.

In short, temperature doesn't seem to really affect your SoC directly; it affects the overall capacity of the battery which changes the SoC calculation by reducing the denominator.

 

[Rivian Rider]

Good thing you turned off Gear Guard so you didn't have to see the garage urinators.

Nothing wrong with some natural disinfectant

 

[Aardvark]

Great test. I can't think of anything else you could have done.
Still, even though better than your previous 5% daily loss, 1.62% per day still seems excessive to me given your extreme energy conservation methods.
A standard battery is 92.5 kWh. So assuming that's approximately 90 kWh of usable capacity, you lost 1458 kWh every 24 hours, or an average equivalent continuous load of 61 watts for your entire 8 days. With everything you turned off, and using shipping mode, I'm really curious of what could be drawing that much power.
Thank you for writing up your results.

 

[Time2Roll]

Yes that is confusing. The percentage displayed shows a 13% loss but the range displayed shows an 83 mi loss. Rivian explains this but claiming that the mileage can go up and down based on weather conditions (that in warmer weather, 13% loss would equate to less miles). I frankly don't get this and find it confusing that their percentage and range don't correlate. Maybe someone else can explain this.

This is from cold soaking the battery. Vehicle knows it will be using additional energy to warm the battery and maybe the cabin. This uses energy from the battery and is not turning the wheels. This drops the amount of energy available to turn the wheels so the stated miles range drops more than the level of charge.

That sudden drop as the vehicle was started was probably an update once the computer is on again to recalculate the latest estimate.

Of course the idea then is to use the prepare to charge function and hit that L3 charger again if additional range is needed to return home.

 

[Rivian Rider]

Great test. I can't think of anything else you could have done.
Still, even though better than your previous 5% daily loss, 1.62% per day still seems excessive to me given your extreme energy conservation methods.
A standard battery is 92.5 kWh. So assuming that's approximately 90 kWh of usable capacity, you lost 1458 kWh every 24 hours, or an average equivalent continuous load of 61 watts for your entire 8 days. With everything you turned off, and using shipping mode, I'm really curious of what could be drawing that much power.
Thank you for writing up your results.

I'm told a lot of it is energy that's needed to keep the battery itself warm. I also think that the app connectivity is a potential source of the drain. Be curious to see someone test that out by leaving a car out for a couple days and checking it with the app on occasion and then running the same test without checking the app at all.

 

[Rivian Rider]

This is from cold soaking the battery. Vehicle knows it will be using additional energy to warm the battery and maybe the cabin. This uses energy from the battery and is not turning the wheels. This drops the amount of energy available to turn the wheels so the stated miles range drops more than the level of charge.

That sudden drop as the vehicle was started was probably an update once the computer is on again to recalculate the latest estimate.

Of course the idea then is to use the prepare to charge function and hit that L3 charger again if additional range is needed to return home.

OK, so let's say all kinds of things happen that require the battery to calibrate itself and tell you how much range you have. Fine. Then, your car should know how much range you're going to have.

And then, when you drive, assuming that the weather conditions have remained the same, and you're driving habit hasn't changed, then the range should still hold. But no it just drops while you're driving. I don't understand why the computer or software can't calibrate that in advance.

I'm not a battery scientist, but I would expect that something like an estimated range should turn out to be accurate within 2 to 3%.

 

[Rivian Rider]

Anyway, all this may sound like complaints. But I'm just trying to understand the system and how it works.

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