Charging your R1T 70 or 85%

[rivian_panda]

Do you charge to 70 or 85?

the warranty is 70% charge retainment for 8 years or 175K.

Why do I care if 85% will be deteriorating the battery more moderately? if within 8 years the truck can’t hold 70% charge Rivian will give me new battery.

Do I have to charge to 70 every time to utilize the warranty.

I would like to charge to 80 and not 85%. I think 80 is a good balance. Get a bit more in mileage and battery deteriorate just a little bit more.
Thoughts ?

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[fallen888]

I go to 85% on the daily. Prior to Rivian I went to 90% with my Teslas. I don't sweat it too much because I don't plan on keeping it more than seven years anyway. Battery pack or motor issues without warranty scare me, so I'd be looking to upgrade about a year before warranty expires (and value drops) at the latest.

 

[kylealden]

70% is pretty conservative for the battery warranty. Typically these types of batteries are good for around 1000 full discharge cycles before seeing >20% or more depreciation - that's over 200,000 miles with halfway decent efficiency. The odds that you'll have to worry about 70% with any charge regime are pretty low.

The argument for a lower default SoC cap is more about keeping it to 5-10% instead of 10-15% in the first few years, which is pretty typical depreciation. There are a lot of variables in the mix and it's a bit of the roll of the dice any way you slice it - if you're going from 70% to 5% often, you're probably hurting the battery more than if you went from 85% to 20% on the same drives, for example. The important bit is to stay in the middle and away from the ends where practical.

At the end of the day, my advice is the same as the dealer that sold me my first motorcycle: drive it like you own it, not like you stole it, and not like you borrowed it. There's no sense bending over backwards to live your life on 70% of the battery you paid for just so that it theoretically depreciates a little less - the theoretical savings doesn't matter if you never use it! But, if you use less than 50% of the battery in a given day and can charge at home, there's absolutely no reason to charge over 70% unless you need to; the risk is low, but the benefit is zero.

In practice you're never going to be able to causally connect range loss to a single factor. Go over 70% when you need to and don't sweat it, even if that means 85% every day. It's a tool, not a jewel.

 

[SeaGeo]

Why would you charge it to 85% unless you're driving more than about 190 miles a day? I just don't understand the desire of charging to 85 or 100% unless you actually need it.

 

[fallen888]

Why would you charge it to 85% unless you're driving more than about 190 miles a day? I just don't understand the desire of charging to 85 or 100% unless you actually need it.

Sometimes I don't know if I have to go on a longer trip until that day. And by longer I mean 1+ hr vs. a daily typical of 20 mins or less. It's good to have buffer for some peace of mind, if nothing else.

 

[pc500]

I also wonder how much buffer the battery has. I noticed Teslas have notoriously low range loss, which I assume is due to headroom.

 

[SeaGeo]

I also wonder how much buffer the battery has. I noticed Teslas have notoriously low range loss, which I assume is due to headroom.

Teslas have a relatively small buffer. The R1T is at least 10kwh with about 125kwh usable out of 135kWh. That being said I feel like somewhere had the pack set at 144kwh total, but I don't remember where that was from and my confidence level is low.

 

[time]

Now I thought the 70/85%/100% thing was mainly for DC charging. I was surprised to see this in the Rivian because it was never even mentioned or even an option in my BMW i3's. Does it really effect us that much if we're daily Level 2 charging at home?

 

[kizamybute']

Why would you charge it to 85% unless you're driving more than about 190 miles a day? I just don't understand the desire of charging to 85 or 100% unless you actually need it.

Because you never know! You charge to 70%. You go drive 100 miles. You're not a "conservative" driver, so you get less than the expected 2 miles per wh. Appears more "spirted" drivers will get closer to 1.75 miles per wh/hr. So, that means you use 57 kwh of the battery in that 100 mile drive. You only charged your 135 kwh batter to 70% (94.5 kwh). Add in typical vampire drains and what not and you've probably used up 60 kwh. You have just 34.5 left when you get home. OK, not too bad, but wait, an emergency popped up and you have to drive 50 miles to get to it. Now what?

95%+ don't "need" 300 miles in range on a daily basis. But, just because you don't need it, doesn't mean it's bad to have it for the unexpected times you may need it. The point of having 300 miles in range isn't only for long distance travel, it's to try to remove any range anxiety. Do you go to the gas station and just get 3/4 tank of gas or do you fill up? Most fill up each time. Do you charge your phone to 70% battery and unplug?

There's been many occasions I've forgotten to plug in at home. Thankfully, I always make sure to charge the car whenever it gets below 40%, just to be safe. The point in convincing people to switch to EV's is that you can do so without having to alter your habits, which most people don't want to have to do.

My dad had the same Tesla I had. I always charged to 85 to 90%. He travelled a lot and always charged to 100%. After three years, his car charged to a range 10 miles more than mine did. Probably not the norm, but just an example that it likely doesn't hardly matter.

Charge it up to whatever YOU feel comfortable with and don't worry about it. 100% probably not the best to do every day. But, if that makes you feel better, then have at it. In 5 years, probably will have less than a 2% impact on degradation. While it says 100%, I can assure you, Tesla, Rivian and all others have some type of buffer built-in there already. Just as many EV's will travel 5, 10, 15 miles past "0" when on empty. Don't recommend testing it, but just more proof that there's a buffer built-in beyond what the 0-100% range reflects.

With the Tesla, I don't plug in every day as I find the car uses more power from the wall when plugged in than when it's not plugged in. Apparently feels the freedom to run more checks and maintenance on itself. A waste of energy if I come home with over 60% in range, will typically go another day. As noted, will rarely go below 40% without charging unless I forget. That rule of thumb however, gives me that 40% buffer still in case I do forget.

A lot will depend on your daily drives. If you almost never go more than 10-15 miles a day, then why plug it in all the time? Unless you want the security blanket that range is there if something comes up and you need it.

I've read several things that indicate the number of charging cycles is harder on a battery than the level you charge it. Many of the home back-up batteries warranty based on charge cycles, rated for x-number of charge cycles. So, if that's accurate, then plugging it in every day is worse for it than charging it to 90%.

Long story short, do what you feel best with and don't worry about it. Just my 2 cents based on my own experience after 9 years in several Teslas.

 

[timesinks]

Do you charge to 70 or 85?

the warranty is 70% charge retainment for 8 years or 175K.

Why do I care if 85% will be deteriorating the battery more moderately? if within 8 years the truck can’t hold 70% charge Rivian will give me new battery.

Do I have to charge to 70 every time to utilize the warranty.

I would like to charge to 80 and not 85%. I think 80 is a good balance. Get a bit more in mileage and battery deteriorate just a little bit more.
Thoughts ?

The warranty is written so that if you don't take care of the battery, they're still only going to have to replace a small number of them. I would rather not trash it unnecessarily because I see a 95% chance I have a trashed-but-not-trashed-enough-to-get-a-warranty-replacement battery and a 5% chance I get a new battery during that time period. Taking care of the battery, I expect it'll easily have 85-90% or more of its original capabilities when that warranty expires and many, many more years of useful life.

Now I thought the 70/85%/100% thing was mainly for DC charging. I was surprised to see this in the Rivian because it was never even mentioned or even an option in my BMW i3's. Does it really effect us that much if we're daily Level 2 charging at home?

These batteries will last seemingly forever if you keep them at a 50% state of charge. The more time you spend further away from 50%, the harder it is on them. They will take thousands of full cycles, empty to full, sure. Rivian recommends that you charge to 70% on a daily basis unless you need more. There is no harm in sometimes charging higher, but the battery will last longest if you minimize the time spent above 70% and especially above 85% (and, similarly, below 30% and especially below 15%).

 

[RayzorBEV]

I have been charging mine to 100%4 times total during my last road trips (900miles) and and this is what is shown in Conserve mode

 

[Ladiver]

Why would you charge it to 85% unless you're driving more than about 190 miles a day? I just don't understand the desire of charging to 85 or 100% unless you actually need it.

Why wouldn’t you? You paid for it, right? It’s not like that upper 30% requires additional $$$.
As a volunteer for local Search and Rescue, I’m on call 24/7/365. We may get a call and have to drive 50+ miles one way. I almost always charge 70% anytime I can plug in. On the weekends (starting Thursday night) I charge to 85% because I know I drive more on the weekends. I have only charged to 100% twice.

 

[jollyroger]

Just a quick trick, I got one of the early Hyundai ionic electrics and they didn't even have a selection of how far you wanted to charge. So the vehicle would charge to 100% no matter what you did.

I set up the smart charger to shut off however at a specific time, so I could tell the ioniq to be ready at 9:30am but have the EVSE shut off at 8:00am, that put me around 70%

Maybe you could do something similar with the Rivian and figure out how to charge to 80%

 

[Canthoney]

My Kia EV6 recommended charging to 100% at least once a month so I think having some variable charging between 10-90% is fine for the battery health.

 

[BrayBay]

When I get my Rivian R1S, I plan to charge to 70% everyday unless I know I'm travelling a lot that day. Rough math is about ~200 miles on 70%. Even with a 100 mile commute round trip I would still be in good shape if I charge everyday.

I do the same with my smartphone, only charge until 80% and that lasts me everyday to about 20%.

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