Is there a way to preheat the battery and get regenerative braking before driving?

[Goldmaniam]

I live about 3 miles up a fairly steep mountain, and every morning when I leave, I get a message about 1/3 mile down the hill that regenerative braking is reduced. I end up riding the brakes all the way to the bottom. It seems to be the same whether it is 30 degrees or 70 degrees. Is there any way to actually get regenerative braking to stay on by preheating or anything?

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[Phatman113]

This is a hotly debated question.

Rivian has stated that the vehicle will use the motors to pre-heat the battery when you use climate control.
It's much more effective when plugged in as they default to less power to save range (no way to modify that currently)
There's debate as to the actual functionality as to if it needs a scheduled climate action vs just pressing the climate button, so you'll want to test that to see what works best for you.

I can state that I've seen it warm the batteries (usually only up to 50* or so, but that was in the winter, so maybe more when it's warmer out) when done with a scheduled climate pre-heat.

 

[sherold]

What charge level and battery temp are you typically starting at in the morning?

 

[Goldmaniam]

I start at 70%, and it has been in the 60s in the morning. Battery has been at 61 degrees

 

[swaggner]

There are lots of theories on this, with some finding that higher battery state of charge (percentage) can cause more limited regeneration. Try starting at 50% one day, and see what happens. Please let us know!

 

[Goldmaniam]

I will try that tomorrow

 

[André]

The only way to get the battery properly prepared is to charge it for 20-30 minutes just before going by increasing the targeted charge %. Using the climate control will work if the energy used by it brings the SOC below the targeted % and start the charger if plugged in (takes more time).

 

[csharp]

As Andre' has said, I have found I can force it by only charging to 65% during the night, and then 30 minutes before I need to leave, have it finish the other 5%.

 

[sherold]

Hmmmm, should be perfect charge level and temps to have full regen available. From the moment you put the truck in Drive, to when you start your continual descent, roughly how much of a distance is it?

 

[COdogman]

I can’t find mention of it at the moment, but I thought regen was reduced on steep declines? So it may have nothing to do with the temperatures.

 

[Riviot]

As Andre' has said, I have found I can force it by only charging to 65% during the night, and then 30 minutes before I need to leave, have it finish the other 5%.

If only Rivian had scheduled DEPARTURE charging...

 

[mudito]

When I did my Colorado trip last month, While I was going up to Loveland pass, I selected the fast-charger right after the descent so while going up, my truck stated "pre-conditioning" the entire time. I had re-gen all the way down.

A few days later, when heading back, I didn't do that and I had my regen-braking limited just as OP stated in the last post. The "funny" thing is that the battery temps shown in the dashboard where pretty much the same in both cases (~80F when starting the descent) so I'm not sure why it was different.

Manual pre-conditioning button should work wonders in these cases...

 

[carsly]

If only Rivian had scheduled DEPARTURE charging...

THIS

Works perfectly on my Cybertruck. Plans backwards from scheduled departure to start charging and also have a separate option for pre-conditioning the cabin, which it figures out on its own working backward from scheduled departure. Great in the winter in the northeast as the cabin is warm and the batteries are pre-warmed a bit.

Other plus is that the average state of charge of the battery over time is lower which should extend lifespan - e.g., if I plug in at 7pm at 50% with a target daily charge level of 70% it will hold the 50% overnight and start charging 3-4 hours before departure (7kw wall charger). That's better for the battery than charging from 50-70% from 7-10pm and then holding the 70% until departure at 7am.

It's a subtle difference in approach, but should add measurably to extending battery longevity and reducing degradation. Plus the pack is warmed naturally during charging so might as well warm the pack before you go instead of burning energy to warm the pack when you plug in, it cools off again overnight, and then having to warm the pack again in the morning before departure. So better for the battery and more efficient overall.

 

[André]

and

THIS

Works perfectly on my Cybertruck. Plans backwards from scheduled departure to start charging and also have a separate option for pre-conditioning the cabin, which it figures out on its own working backward from scheduled departure. Great in the winter in the northeast as the cabin is warm and the batteries are pre-warmed a bit.

Other plus is that the average state of charge of the battery over time is lower which should extend lifespan - e.g., if I plug in at 7pm at 50% with a target daily charge level of 70% it will hold the 50% overnight and start charging 3-4 hours before departure (7kw wall charger). That's better for the battery than charging from 50-70% from 7-10pm and then holding the 70% until departure at 7am.

It's a subtle difference in approach, but should add measurably to extending battery longevity and reducing degradation. Plus the pack is warmed naturally during charging so might as well warm the pack before you go instead of burning energy to warm the pack when you plug in, it cools off again overnight, and then having to warm the pack again in the morning before departure. So better for the battery and more efficient overall.

You can also remotely defrost the cabin in the Rivian but it won’t condition the battery unless it brings the SOC below the targeted % and the truck in plugged in. Tesla does a better job by heating the battery immediately when you defrost the cabin. Very convenient if you need all the available range as it will use it to warm up the battery while driving otherwise and as others said you won’t have full regen for the first few miles. I really can’t get why Rivian doesn’t do that.

 

[carsly]

and
You can also remotely defrost the cabin in the Rivian but it won’t condition the battery unless it brings the SOC below the targeted % and the truck in plugged in. Tesla does a better job by heating the battery immediately when you defrost the cabin. Very convenient if you need all the available range as it will use it to warm up the battery while driving otherwise and as others said you won’t have full regen for the first few miles. I really can’t get why Rivian doesn’t do that.

I've noticed this too - that the Rivian pulls from the battery to pre-condition the cabin even though it's plugged in to shore power. Why?

If a Tesla is plugged in, it will pull power from the grid first for the reason you note, to keep the power in the pack for driving.

It also feels like the Rivian isn't able to distribute shore power to do two things (or more):
- charge the battery AND
- precondition the cabin AND
- preheat/cool the battery for travel

My hypothesis is that Rivians HVAC is only capable of running off the battery pack, nothing else. Otherwise it's just odd.

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