Charging Level Question

[RMSko]

I got my '26 R1S about two weeks ago and have a question about charging. When I picked up the car, they told me that a charge to 70% is recommended but also that I should charge to 100% about once/week. I don't drive the car very much and so I end up charging it only about once/week. Putting aside that 70% seems low (I'm coming off a Lucid and they recommended 80% or 90%), I'm wondering what people think the best charging level is.

Also, how much does the range decrease in the winter (I live in NJ). When I picked up the car they said that the Gen 2's have a better battery and it should only be impacted by about 5%. That would be great if true, but I'm a bit doubtful it would be that low.

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[zefram47]

If you're already only charging once a week you aren't driving enough to care about charging to "only" 70%. Lithium batteries like being in something like the 30-70% realm with below 50% seemingly preferred along with more frequent but shorter charging sessions. In other words, if you only use 10% per day, it's better to charge daily than to wait and do a 10-70% charge once per week. I charge to 70% daily and if I need more, I crank it up and don't worry about it. If I do need 100%, I try to set it to finish about the time I want to leave so it's not sitting at high (or low) state of charge for any longer than necessary as that's also bad for the battery. Don't over think it...charge to what you need and just drive the truck.

 

[md2023]

I charge to 85% regularly (3-4 times a week) and 100% whenever I need more range on a particular day (2-3 times a month). After 45,000 miles, I notice no degradation.

 

[UnsungZero_OldTimeAdMan]

If you have a Standard pack you have LFP chemistry cells. These need to be charged to 100% periodically to aid software’s calibration of the way it measures state of charge (a derivative of voltage readings).



If you have Large or Max, you have NMC. Charge to 100% only if you must for long distance travel, in order to reach first available charging stop. Do not charge to 100% and let it sit at that state without use. For long trips, it’s actually better to not charge to full if charging infrastructure allows you to recharge sooner. Charging slows when approaching full. So for sake of time/efficiency, best to keep SOC to within 20-80% range. And with NMC you do not need to charge to full to calibrate software.



Regardless of LFP or NMC, if long term storage or infrequent use, around 50% is ideal. Just enough for local errands and no stress on battery chemistry. That said current state of battery tech is much less prone to degradation. Most fears are carried over from outdated past.

 

[RMSko]

Thanks for all the replies. I have the dual max battery and so I’ll follow the NMC guidance above.

 

[UnsungZero_OldTimeAdMan]

Thanks for all the replies. I have the dual max battery and so I’ll follow the NMC guidance above.

Delivery and call center generalists aren’t always knowledgeable. So you have to be on your toes.

 

[hammick]

We have a '25 G2 R1S Tri. My wife drives daily about 25 miles. In the warmer months we charge to 55% nightly and in colder months to 60%. We take long road trips fairly often and charge to 100% the night before and DCFC as needed on trips. Charging to 100% several times a years should help calibrate the BMS.

 

[solaskaze]

If you have a Standard pack you have LFP chemistry cells. These need to be charged to 100% to aid software’s calibration of the way it measures state of charge (a derivative of voltage readings).

Why doesn't their software just do "the right thing"? That is, why does OP have to guess and consult random youtube videos, the UI is very clear on "70% daily", all manufacturers try their best to get accurate range estimate ... if they want calibration, literally let the car tell the user it's time to allow a 100% charge: is that OK? (yes/no) ... at a minimum. Or automatic.

Many other vendors/large-battery appliances are now finally putting this final touch in the "smart charging" already (e.g. every 10th charge will charge to 100% by default, everything else is 80%).

 

[mkg3]

With all due respects to everyone, you are overthinking the battery SOC issue.

Just plug it in every night if driven and set the limit to 80%, then forgettaboutit.

When needed, charge to 100% for road trips and not over think it.

The battery will outlast the vehicle most of the time and almost certainly the ownership duration.

 

[lefkonj]

Had a Gen1 for over 2 years, charged to 85% about every 10 days, didn't notice a thing. I have a Gen2 now and continue this method. When I picked it up they told me to charge to 100 every few weeks in addition to the 85% as needed

 

[UnsungZero_OldTimeAdMan]

Why doesn't their software just do "the right thing"?

This has nothing to do with software. More to do with how LFP and NMC chemistry differs, fundamentally. Ford has similar guidance for LFP equipped Mach-E, as do other OEMs who use LFP cells.

As for Rivian employee not giving accurate information... You work for a living don't you? are you and your fellow employees always on the same page knowledge-wise? And not all are equally good at their jobs? Look at price of R1. How many Rivian delivery specialists and call center operators can actually afford one? or even own/drive EVs themselves? These are not high level, high paying jobs. And, as with any other profession, some people care more about their jobs than others.

why does OP have to guess and consult random youtube videos

OP is vehicle owner and operator. Who else bears more responsibility in knowing how to use and operate a piece of machinery they own? Rivian employees are just regular people making a living. They are not your mom, dad or nanny. Whatever it is you own, it behooves you to know your own shit. And Engineering Explained is not "some random YouTube" channel.

 

[savethemanual]

OP is vehicle owner and operator. Who else bears more responsibility in knowing how to use and operate a piece of machinery they own? Rivian employees are just regular people making a living. They are not your mom, dad or nanny. And Engineering Explained is not "some random YouTube" channel.

I understand where you're coming from, but it just does not make sense for any major purchase. The OEM should have clear recommendations as they are the entity who has deigned and tested the item purchased. From there, it's up to the owner to differ from those OEM recommendations.

 

[solaskaze]

This has nothing to do with software. More to do with how LFP and NMC chemistry differs, fundamentally. Ford has similar guidance for LFP equipped Mach-E, as do other OEMs who use LFP cells.

We're talking about the UI in the car that tells the customer what to do. That's software.
The manufacturer embedded firmware that monitors and tracks SOC. That's software.

OP is vehicle owner and operator. Who else bears more responsibility in knowing how to use and operate a piece of machinery they own? Rivian employees are just regular people making a living. They are not your mom, dad or nanny. Whatever it is you own, it behooves you to know your own shit. And Engineering Explained is not "some random YouTube" channel.

I think you are conflating employees with car software/UI.
To quote Engineering Explained directly: "Is this the manufacturer's problem? ***Absolutely***"

 

[CrazyOne]

Set it to 50 or 55 and charge daily. Always keep it plugged in when at home. It will help the 12v battery life too. Those aren't cheap. 50% or 70% won't make a massive difference in the long term. Over ten years it may change the degradation by a few percentage points. High voltage (high SOC) above 80% and high temperatures are the causes of degradation. Both together is the worst. Store NMC at 100% in triple digit temperatures for 1 year can decrease capacity by 10% - 20%.

This is inline with the generally accepted best practices for NMC. I have never heard anyone saying that NMC should be charged to 100% weekly. This is true for other chemistries.

 

[UnsungZero_OldTimeAdMan]

We're talking about the UI in the car that tells the customer what to do. That's software.
The manufacturer embedded firmware that monitors and tracks SOC. That's software.



I think you are conflating employees with car software/UI.
To quote Engineering Explained directly: "Is this the manufacturer's problem? ***Absolutely***"

It doesn't need to be in the UI. It IS in the Owner Guide. Another thing every owner is responsible for reading (but many don't bother).

Whatever. Give your feedback to Rivian directly through the mobile app. I'm not the one you need to convince that you are right. Open app > scroll main screen down to "share feedback"

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