With Riv's do I need to adhere to the 80%-20% battery rule?

[paco180]

Rivian uses the 2170 battery, which have the new chemistry almost identical to Tesla. ( lookup research on samsung 5000mAh) Rivian is a new company, and they are been very conservative, (very understandable) you will see in the future, new guidelines to 90%.

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[CrazyOne]

Not really. Since Tesla develops their own batteries and SW to control them, it's fine for Tesla. Rivian uses Samsung batteries and what works for Tesla may (probably) not work for Rivian.

Each company that develops battery has a different and unique build and controlling logic. The 20%~80% range is a generic guideline for all Li-ion batteries.

Since Rivian recommends 70% for routine charge level, perhaps they are being overly conservative (to minimize potential warrantee costs) or that Sammy batteries are more sensitive to idle charge level. Also Rivian's power management SW may not be as sophisticated compared to others.

I do charge my Tesla to 90% (as told by Tesla to do) as a routine and often it overcharges into 92~94% range about 25% of the time. That said, it doesn't sit idle for too long after being charged most of the time.

Old Teslas almost exclusively used Panasonic cells. LFP is from CATL. Just one of the many sources of this info.

I would trust Panasonic a little bit more than Samsung, but they are largely the same cells

https://www.cnbc.com/2022/07/13/pan...ctric,commercial and grid-scale installations.

 

[the long way downunder]

The question with one meaning and one hundred answers. : )
Over the last decade, I've simplified it down to this infallible methodology:
Step 1: charge enough to reach the next charger, plus 50 miles' range "margin of error"
Step 2: drive half way, then either slow down or speed up to maintain that surplus 50 miles

Whether the next charger is the same charger at home overnight, or a CCS or a Supercharger or a destination charger, the same Step 2 applies.

Range is a distraction. The important factor is total trip time. The quickest trip time requires arriving at each charger with the optimal state of charge to acquire the necessary additional energy to reach the next charger with the optimal state of charge.

Keep in mind that the charger "now" is faster or slower or the same as the "next" charger.

Imagine a situation where you're charging at home at 12kW and you want to leave and start your road trip. If your first charging stop is a RAN at 217kW peak, when do you stop charging at home and depart? The answer is complicated, but the the simplest answer is Step 1: charge enough to reach the next charger, plus 50 miles' range "margin of error". Now imagine you're at a RAN, charging has slowed to the usual 100kW as the battery overheats. The question becomes "how long to keep charging at 100kW 'now' when the 'next' charger is a 150kW generic CCS? The answer is to apply "Step 1:" to the 'next' charger. How long will you need to be at the 'next' charger?

Again, range is a distraction. The important factor is total trip time. Total trip time is determined by the kW performance of each charger. Charger kW is determined by arriving with the optimal SoC to achieve the "fattest" charge curve.

Each charging stop adds complexity to optimize total trip time.

The infallible method I've found is to "Step 1:" (charge enough, no more) and "Step 2:" (drive half way, then adjust mi/kWh to arrive with that 50 mile surplus. With practice and on familiar legs of familiar routes in familiar weather, I'll cut that surplus margin down from 15% to 5%. On unfamiliar routes, I'll pad the starting margin out to 20% simply because the reward for success is far smaller than the cost of failure. : )

 

[Indy avocado]

Step 1: charge enough to reach the next charger, plus 50 miles' range "margin of error"
Step 2: drive half way, then either slow down or speed up to maintain that surplus 50 miles

Pretty good basics. I wish the CCS architecture was better, you could cut that 50mi buffer to 20-30mi and get even more time in the fastest charging part of the battery.

As said by others:
Charge to 85-100% immediately before road trips. Try to not let the battery sit for hours and hours above 90-95%. But don't fret over it. How long does your cell phone sit at 100% every day? For most people, several hours a day, every day.

Target arriving at a fast charger with ~10-15% battery. It's not going to hurt it as long as you can recharge. Getting down to 0% will stress it, but not too bad - just get it charged up ASAP. the 20-80% range is really about long-term resting state. I aim to keep my truck between 40 and 70% on a day-to-day basis, and then charge up to 90-100% before road trips. (I wish the charging system had a schedule on it so you could have automatically it finish right before departure, but I have been handling that manually.)

Also recommend charging up to 85% if there's a reasonable chance of a long duration power outage (big storms/hurricanes/tornadoes, etc.). It's unlikely the last 15% of battery up top is going to be critical, but you want to have as much range as possible, especially if you live in a hurricane area.

 

[DB-EV]

So dont charge over 80% right?

I don't think so; again its your tolerance etc.

Case in point, when I go on ski trips (sometimes weekly in the winter), I charge to 100% and leave in conserve. You should obviously get comfortable or not do that, but I limit how often I do that; mostly it is off of L2 charging at home.

I have called Rivian to ask and they basically said, it is like an iPhone, even when you charge to 100 there is some at the top (and bottom again as you will see on the posts). People are guessing there is 133-135 usable on 141 kw battery.

I would not, however, charge to 100% and leave the vehicle sitting, or DCFC (high speed charge) all the time or frequently to 100%. Note that when / if you DCFC to 100% the car does ramp down the speed near the top of the pack.

Only been about 3 month and 5000 mi but no range loss. In fact, Rivian appears to have increased the range through an OTA update so that ATs get 301 stated in conserve (in coolish weather at highway speed in conserve I arrived at a 240 mi away charger with 40 miles of range, and because I knew I had plenty to spare parts of that were driving significantly but safely over a 65 mph speed limit).

 

[mkg3]

Old Teslas almost exclusively used Panasonic cells. LFP is from CATL. Just one of the many sources of this info.

I would trust Panasonic a little bit more than Samsung, but they are largely the same cells

https://www.cnbc.com/2022/07/13/panasonic-new-factory-in-kansas-to-produce-batteries-for-tesla-evs.html#:~:text=To date, Elon Musk's electric,commercial and grid-scale installations.

Not true statement and the reporting, in typical CNBC fashion, is sloppy and misleading. Much like the rest of their financial headline grabbing sound byte reporting.

The Panasonic batteries for Tesla are Tesla designed 2170 (21mm diameter, 70mm length) batteries. What Sammy makes are their own design with different energy density, not Tesla's.

Tesla's 4680 (48mm diameter, 80mm length) batteries are also Tesla design and most likely will be mass produced along with Panasonic (they are investing in Tesla battery manufacturing). Furthermore, it's the controller/power management SW that are most important - which is Tesla unique, just as Rivian's is unique to the R1.

One shouldn't confuse just buying supplier battery versus buying own designed products from an outsourced manufacturer. Just like Apple doesn't make their own HW but designs vast majority of their own products - internal and external.

 

[CrazyOne]

Not true statement and the reporting, in typical CNBC fashion, is sloppy and misleading. Much like the rest of their financial headline grabbing sound byte reporting.

The Panasonic batteries for Tesla are Tesla designed 2170 (21mm diameter, 70mm length) batteries. What Sammy makes are their own design with different energy density, not Tesla's.

Tesla's 4680 (48mm diameter, 80mm length) batteries are also Tesla design and most likely will be mass produced along with Panasonic (they are investing in Tesla battery manufacturing). Furthermore, it's the controller/power management SW that are most important - which is Tesla unique, just as Rivian's is unique to the R1.

One shouldn't confuse just buying supplier battery versus buying own designed products from an outsourced manufacturer. Just like Apple doesn't make their own HW but designs vast majority of their own products - internal and external.

BMS is important, but not that hard. As long as company is not sloppy line Nissan and is willing to spend the money. Keep cells in a certain voltage and temperature range and they are happy.
Apple designs the chips, but does not tell TSMC how to make them. How transistors are printed is 100% TSMC.

 

[zymolysis]

I don't think so; again its your tolerance etc.

Case in point, when I go on ski trips (sometimes weekly in the winter), I charge to 100% and leave in conserve. You should obviously get comfortable or not do that, but I limit how often I do that; mostly it is off of L2 charging at home.

I have called Rivian to ask and they basically said, it is like an iPhone, even when you charge to 100 there is some at the top (and bottom again as you will see on the posts). People are guessing there is 133-135 usable on 141 kw battery.

I would not, however, charge to 100% and leave the vehicle sitting, or DCFC (high speed charge) all the time or frequently to 100%. Note that when / if you DCFC to 100% the car does ramp down the speed near the top of the pack.

Only been about 3 month and 5000 mi but no range loss. In fact, Rivian appears to have increased the range through an OTA update so that ATs get 301 stated in conserve (in coolish weather at highway speed in conserve I arrived at a 240 mi away charger with 40 miles of range, and because I knew I had plenty to spare parts of that were driving significantly but safely over a 65 mph speed limit).

" Note that when / if you DCFC to 100% the car does ramp down the speed near the top of the pack."
In my (admittedly limited) experience, DCFC charging begins to taper even before it reaches 50% SOC, and it ramps down dramatically as it approaches the higher percentages.

 

[LivingInKaos]

If your DCFC trip can facilitate more 200kw+ stops and they are on route, if you can keep your charging between 0-60% you'll actually make better time than charging to 85-100% and trying to go as far as you can. Now I know that's not always feasible, but that's why you plan

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