Rivian Battery Poll - VOTE HERE

[ajdelange]

And indeed item 128 is part of a heat pump that pumps heat from the battery and can transfer some of it (note that it is really a de-superheater) to the cabin (which is, of course, a smart thing to do). But it does not pump heat from the outside air as Tesla does in the Y. The outside air is a source of free (well, not totally free - it takes about a kWh to get 3 kWh but the 2 kWh are effectively free) heat. I haven't seen anything on how much anyone thinks this adds to the range of the Y but Tesla's analysis and testing must have shown that it is worth the added complexity. With this closer look it appears even less likely that Rivian uses this heat source but not using it by no means implies that Wh/mi will double in cold weather. I'm guessing that using it might have saved them a few 10's of watthours per mile in moderaely cold weather i.e. improve cold weather range by less than 10%.

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[trickflow]

While I am leaning to get the 180 kwh battery, I want to see how much the difference in weight will effect range and cost. It could be that a 135 get about 350 miles (just a WAG) due to it weighing less and a 180 get 410 (again a WAG). If the cost difference is thousands of $$$ it may not be worth the larger battery. Not to mention that the fastest R1T will be the 135 kwh model. So I will wait and see what those options are once the config builder is out.

To note everyone saying that you need to keep the battery between 20-80 percent all the time is wrong if you are road tripping. If you bring the battery to 95% (so you get regen) and drive it down to 5%, there is no issue as long as you do not keep it there for a longer period of time. I.E. you charge to 95%, start driving right away and once you hit 5% you plug in right away is fine. What batteries don't like is being at 100% and not discharging, and bringing it down to a low SoC and leaving it there for a few days is also not good. But during a road trip, it's OK to use 90-95% of the batteries capacity.

Even for towing, it could be that the weight savings of the 135 kwh battery would be best. RJ mentioned that towing will take up to 1/2 range away. So if my WAG would be correct, that would mean 175 miles vs 205 miles. Again, depending on the weight savings it could be closer to 185 vs 200. Problem is, like my guesses here, none of it may be correct. It's the real world numbers that matter and I intend on asking Rivian some of these exact questions before I drop this amount of cash on a vehicle. I am pretty sure they are going to do some tow testing as I would hope the truck would get an SAE J2807 towing capacity test.

 

[CappyJax]

Because I tend to keep vehicles a long time 10+ years, I am always looking for longevity. With BEV's, having the largest battery will allow for the least stress on the battery. If I have 400 miles of range, but recharge after 200 miles, that is much less stress on the pack than if I am going down to 10% and recharging to 90%.

Also, have a larger battery pack means a lot less stress on the pack when you goose it. If you are pulling 562kW out of a 135kWh battery pack, that is around 4.2C. If you are pulling 522kW out of a 180kWh pack, then that is 2.9C.

 

[DucRider]

But during a road trip, it's OK to use 90-95 100% of the batteries capacity.

Fixed it for you. The BMS will never allow you to use a true 100% of the capacity as there will be bottom (and almost certainly top) buffers. Tesla is unique in that they eliminate the top buffer and allow the owner to access that portion of the battery (but recommend against doing it on a regular basis). This allows for longer range (for both road trips and EPA ratings), but at the expense of leaving the battery more vulnerable to abuse. I doubt that Rivian will do this.

The only caveat about using 100% is that it requires rolling into a charging station with 0% SOC. Most people would not be comfortable doing this.

Some manufacturers allow for regen even if your SOC is 100% (using the otherwise closed off top buffer), many do not. Once again this is a detail we don't yet know about the Rivian.

But as @CappyJax stated, a larger pack will be stressed less by both spirited driving and fast charging, plus fewer cycles should help with longevity. In reality it is very likely that the battery will last much longer than 10 years no matter how you treat it (there will be some degree of degradation, but something that only time will provide a quantitative answer )

 

[jjwolf120]

o note everyone saying that you need to keep the battery between 20-80 percent all the time is wrong

The reasoning for not charging it up to 100% during a road trip is time. It is more time efficient to charge it to 80% and then go to the next charger and continue on.

 

[DucRider]

The reasoning for not charging it up to 100% during a road trip is time. It is more time efficient to charge it to 80% and then go to the next charger and continue on.

80% is a good rule of thumb, but depending on a lot of variables (the charge curve/taper characteristics being among the most critical) a different charge % might make for a faster trip.

With the Model 3 tapering at a fairly low SOC, some find that charging to 60% (or even less) more frequently will reduce the total trip time (especially when V3 Superchargers are available)

 

[trickflow]

The reasoning for not charging it up to 100% during a road trip is time. It is more time efficient to charge it to 80% and then go to the next charger and continue on.

Understood, but when you charge at your house before the trip, push that battery to the limit so you have as much range as possible. Agree on DCFC, I usually stop charging my M3 when it tapers off.

 

[DucRider]

While I am leaning to get the 180 kwh battery, I want to see how much the difference in weight will effect range and cost. It could be that a 135 get about 350 miles (just a WAG) due to it weighing less and a 180 get 410 (again a WAG). If the cost difference is thousands of $$$ it may not be worth the larger battery.

It will likely be a $10K (+/-$2K?) price bump from the 135 to the 180.
Mach-e is +$5k for 20 kWh.
A WAG estimate of pack cost to Rivian is around $140/kWh (volume weighted industry average in 2019 was $156). There will be markup involved and if Rivian feels like they will be supply constrained on batteries it could be even higher.

 

[ajdelange]

Nobody here knows any of the particulars of the battery, battery management scheme or consumption numbers for the Rivian so all people can do is speculate. There is an obvious temptation for Tesla drivers to try to extrapolate from their Tesla experiences and that's fine as long as everyone understands that the results are extrapolations.

It is true that the extra mass of the battery is going to mean a larger inertia and gravitational loads for the truck with the larger battery. We don't, of course, know what the true capacities of the 135 kW and 180 kW batteries will be but we can guess that the latter will weigh about 33% more than the former and that the inertial load from battery mass will be greater by that amount. But what percent of total mass is battery mass? Based on nominal energy density and a difference in capacity of about 45 kWh we might WAG the battery weight difference at 250 kg. If the vehicle overall weighs 2750 kg with the larger battery (a WAG) then the inertial/gravitational load difference might be 10% greater in the vehicle with the extra battery. But the mass related loads aren't the entirety of the load. And, in a vehicle with regeneration, those loads are less significant than in an ice vehicle. Thus the effects of battery weight difference probably aren't too significant especially at cruise speeds.

 

[Walter P Jenkins]

Im on the fence between the 135 & 180kWh packs. Knowing that the majority of EV’s on the road today have a 300 mile range and are navigating that just fine. Is is necessary or worth it to go up to the 400mile range ?

Would love your thoughts and input here. I get the bigger is better argument, but what other then that is swaying your decision?

You made me think! Maybe the 135 pack is best. Carrying less weight around and therefore more efficient. But even now, it’s hard to tell. How far apart will the charging stalls be. It should take less time to charge with less batteries too. I think I will have to wait and see. How much do the different battery packs weigh? How much do they cost? I‘m not sure which one is best. I live just 50 miles from the plant. I wonder when their next open house will be?

 

[Jehorton]

for me I think it just comes down to need and affordability. I know I don’t need the 400 range when I drive around 400 miles in maybe a months span at the most. I’ll be fine with the 135 and would even consider the smaller pack but want that middle battery the most. Plus that 0-60 time is attractive. Would love to pull up next to the diesel truck that thinks his truck is fast and my electric truck is garbage. Haha

 

[Babbuino]

for me I think it just comes down to need and affordability. I know I don’t need the 400 range when I drive around 400 miles in maybe a months span at the most. I’ll be fine with the 135 and would even consider the smaller pack but want that middle battery the most. Plus that 0-60 time is attractive. Would love to pull up next to the diesel truck that thinks his truck is fast and my electric truck is garbage. Haha

I was also more inclined for the big pack, but now I'm also wondering if the mid one will also perform better off-road since it will be lighter.
Guess it comes down with the actual range of the 135kwh. If its 350 or more, that's should be enough for the 1k mile trip i make every year.

 

[ajdelange]

I did want to comment on the charging advice given here. Ignore it. Keep in mind what we know about batteries in general

1)Fast charging stresses them
2)Charging at high and low SoC stresses them
3)Charging at high and low temperature stresses them
4)Storing them at low or high SoC stresses them

But be guided, ultimately, by what the manufacturer tells you about how to charge your vehicle! He knows lots more about his batteries than you or I or anyone on any forum does.

As an example, Tesla tells us not to Supercharge if we don't have to and to not charge over 90% at home as a matter of course while assuring us that we can leave the car connected to a Level 2 charger set for 90% and charge over 90% prior to leaving for a long trip if we want a couple of extra miles security and use Super Charges while on that trip. These are, of course, in concert with the general principles given above. If we wander too far from those principles Tesla will nudge us back into compliance by putting warnings on our screens, limiting Super Charging and taper.

Now that's Tesla. Rivian is going to be the same but different. The same principles apply but keeping in mind that 90% and 10% are marks placed on the battery gauge where Tesla and Rivian choose to put them (they do not represent 10% or 90% of the actual capacity of the battery) and that the Rivian cell chemistry and configuration will be different, their recommendations are going to be somewhat different but not dramatically. We can also be sure that their software will protect us from our own foolishness.

As Rivian's vehicles start to log some miles knowledge of battery performance and how to best manage them will accumulate and the advice may change.

One final point: study and understand the charging advice Rivian will give us. As an example of this while Tesla tells us it is OK to charge above 90% to pick up a couple of "insurance" miles (each % adds 2.5 - 3) if we read further we understand that we actually get less miles per percent above 90% because above that SoC regen is disabled and each kWh added returns fewer miles than when SoC is less than 90%. Some such considerations may or may not pertain with Rivian.

 

[KickRocksRiv]

So we are a 40/60 split at the 100 person mark..Interesting I would have thought more ppl would be for the 135kWh pack due to the price ok 69k and assuming the 185kWh pack will likely be 8-12k more ! So after all of the Input I’ve extrapolated the data and used the Equation below :
30k x 1 x 0 =0 +100 -40 =60 and came to the conclusion almost everyone buying one of these is rich !

Oh and someone must have selected the 105kWh battery by accident.... right ?

 

[bajadahl]

I'm not rich...but I'm going to "feel" rich after raising two teenage daughters... who also think I'm rich..... FYI - my last new car for myself was that 2000 LX470 in my profile picture that I bought before they were born.... so yeah I remember what it felt like to have a little bit of money....

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