Precondition Battery for fast Charger

[SolartoEV]

They need to add a button to tell the vehicle to precondition the battery. It's a pretty simple enhancement to their software. I am mystified why they haven't already done that.

When would you hit the button?

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[brancky3]

When would you hit the button?

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[jcrigler]

any time i intend to go to a DC fast Charger. I don't need or want to "navigate" to it.

 

[BrentInCO]

Pro tip: launch (accelerate with the pedal to the metal) a few times so that the battery management system does its job, gets the battery temp up to the mid point on the display of around 72 degrees. I regularly camp over a weekend, leaving my Rivian behind, in freezing temperatures for 36+ hours. It’s then a 45 minute drive to the nearest RAN / level 3 charger, before heading back home. Even if the display says ‘preconditioning battery’ for that 45 minute drive, the battery won’t have reached the temperature mentioned above, and will only charge at 23 kw to 118 kw, but if I romp on the accelerator a few times, it charges at capacity ~220 kw.

 

[R.I.P.]

Pro tip: launch (accelerate with the pedal to the metal) a few times so that the battery management system does its job, gets the battery temp up to the mid point on the display of around 72 degrees. I regularly camp over a weekend, leaving my Rivian behind, in freezing temperatures for 36+ hours. It’s then a 45 minute drive to the nearest RAN / level 3 charger, before heading back home. Even if the display says ‘preconditioning battery’ for that 45 minute drive, the battery won’t have reached the temperature mentioned above, and will only charge at 23 kw to 118 kw, but if I romp on the accelerator a few times, it charges at capacity ~220 kw.

Put stress on a cold battery on purpose.

Reader beware this "pro tip" lol.

 

[BrentInCO]

Put stress on a cold battery on purpose.

Reader beware this "pro tip" lol.

It’s already been driven for 40 minutes when I do this, and there’s no snowflake indicating the battery is cold. Minnesotans without garages (Tesla owners)told me to do this years ago with my Model S, when my car either wouldn’t charge at all on a Level 2 or painfully slow on a Level 3, and I’ve not seen any negative results. They had been doing it for years with no negative ramifications. I had the same natural reluctance as you. 150k miles on my Tesla and 26k on my Rivian (11 months in).

 

[R.I.P.]

It’s already been driven for 40 minutes when I do this, and there’s no snowflake indicting the battery is cold.

It is cold enough that the BMS is restricting throughput untill it can get some more heat into the battery, which it will, and your recommendation is basically to force throughput with the right pedal anyway?

You do you, for sure, but you will not find this "pro tip" in the manual under "recommend practices" lol.

I'll throw out a pro tip; baby your machine when you can when it is cold. Whether it is a gas, diesel or electric machine. Letting them come up to temps the way they were designed to is likely less destructive to them than trying to force the issue.

 

[BrentInCO]

It is cold enough that the BMS is restricting throughput untill it can get some more heat into the battery, which it will, and your recommendation is basically to force throughput with the right pedal anyway?

You do you, for sure, but you will not find this "pro tip" in the manual under "recommend practices" lol.

I'll throw out a pro tip; baby your machine when you can when it is cold. Whether it is a gas, diesel or electric machine. Letting them come up to temps the way they were designed to is likely less destructive to them than trying to force the issue.

I babied it many times, with it taking 3 hours to add 100 miles of range. Then I learned this tip, to get the BMS to do what it’s supposed to do. For years now, I’ve been accelerating a few times, to warm systems up, and now it takes just a few minutes to add the 100 miles I need to be able to head the 300 miles home. All of this occurs where it’s a 6 hour drive from the nearest service center. So, risky. Like I said, I was hesitant at first, as you and I think similarly, logically. I’m sharing my experience, am thankful to others who shared theirs, this specific approach to a problem, and perhaps someone else will appreciate me sharing mine.

 

[jcrigler]

interesting stories... but I ask again.... why not just a button on the dash to precondition the battery?
Seems like such simple thing. That feature could put up a clock/timer that says how long that would take given outside temperatures and current battery condition ... and you can gauge your drive to the charger accordingly.

Oh its going to take 20 minutes to get the battery ready, I'll stop by the store and pick up milk...

 

[HarryBrowne]

When would you hit the button?

It frequently takes me several minutes to force the stupid nav app to recognize that I want to charge at a certain charger. The button would save me that time, which often happens while I am driving, so is not optimally safe.

 

[JamuJoe]

I’ve found automatic pre-conditioning to be simple and effective using the nav system. Perhaps the truck is designed to work for the average (well, perhaps above average) driver, not DIY enthusiasts.

 

[SolartoEV]

It frequently takes me several minutes to force the stupid nav app to recognize that I want to charge at a certain charger. The button would save me that time, which often happens while I am driving, so is not optimally safe.

How would you know how long a head of time to hit it? 15 minutes? 1 hour? There is an optimal point for it to turn on and just having it on and running would probably waste more battery aka time to charge then just arriving at a charger with a battery not " pre conditioned".

 

[Dave Cundiff]

How would you know how long a head of time to hit it? 15 minutes? 1 hour? There is an optimal point for it to turn on and just having it on and running would probably waste more battery aka time to charge then just arriving at a charger with a battery not " pre conditioned".

My observation is that our Large Pack and MaxPack have a VERY large thermal mass. They heat up rapidly with charging, slowly with anything else.

Based on this observation, I would guess that starting preconditioning manually, if earlier than needed, wouldn't use much more power than letting the Nav start it at the "optimal" time.

Also, the Nav hasn't consistently recognized whether we're headed to a DC Fast charger or not.

That's why I want the option to start preconditioning manually.

Best to all!

 

[azbill]

There is a simple way to see if the low charge rate is due to the truck or the charger. The Rivian will post a message that charge rate is limited by the charger. If it is posting that message, then it is not due to preconditioning.

I have seen the Tesla chargers limit my rate all summer long. It starts at 200kw fora couple of minutes then drops to 110 kw. Trucks shows limited by charger.

 

[MidnightM00N]

Agree that a manual option would be nice as there are a handful of Ford and Shell DC chargers I use that aren’t on the Rivian nav.

Related question, how far out are people seeing the preconditioning start? I know it’s variable, but my (2015) Tesla never starts more than 10-15 minutes out. I’ve seen people talking about an hour of preconditioning here, but I’ve started well before that even. On a trip this weekend, preconditioning started at 1hr45min and 1hr57 min on different occasions. That’s pretty much the whole drive and seems either ridiculous to me or a software glitch. It’s pretty much the whole trip leg starting almost right after the DC charge that came right before it. Gen 2 dual max.

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