Rivian Battery Poll - VOTE HERE

What battery will you be going with and why ?

  • 105kWh (230+mile range)

  • 135kWH (300+mile range)

  • 180kWh (400+mile range)


Results are only viewable after voting.

bajadahl

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adding the jerrycan to the bus is an interesting idea.... I have no idea how they would integrate it into the cooling system but it certainly makes sense that a bus connector could be installed somewhere on the vehicle.... still lots of questions about if and where.... for example I think if it were to integrate into the vehicles bus then it might be nice to have a custom shaped jerrycan that fits down into the bottom of the fruck giving a new higher floor to the frunk (if that description makes sense) something more of a semi permanent installation... sure it could be lifted out but giving up the bottom 6 inches of the frunk might be something I would just leave in the vehicle all the time....
 

azbill

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Serious question, since I'm not a battery or electrical guy. Would it be feasible to have the jerrycan DC charge the main battery instead, or would there be too much loss?
DC to DC would not work, because as the Jerry Can decreases in capacity, so does the voltage. As the truck battery increases, it then increases to higher voltage. So you would lose close to half the capability of the Jerry Can and it would be slow. A better solution would be to hook the Jerry Can to an inverter and charge as Level 2 (220V). There would be some loss in the inverter, that can vary based on the design.
 

skyote

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DC to DC would not work, because as the Jerry Can decreases in capacity, so does the voltage. As the truck battery increases, it then increases to higher voltage. So you would lose close to half the capability of the Jerry Can and it would be slow. A better solution would be to hook the Jerry Can to an inverter and charge as Level 2 (220V). There would be some loss in the inverter, that can vary based on the design.
Makes sense, thanks for the explanation! I'm not an electrical guy, but seems analogous to air pressure, i.e. voltage equilibrium will stop the charging.
 

ajdelange

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No problem with a DC connection. The Jerry can would be configured as a current source which would deliver as much current as it can in an attempt to keep the bus voltage within limits. Of course it does that by changing its voltage to maintain the needed current. Thus it isn’t just a battery. It is a battery followed by a DC/DC converter.

A very common example of such an arrangement is the Maximum Power Point tracking circuit in a solar cell array. As the array gets shaded or the sun goes down
the system boosts its voltage to match the load’s requirement.

It should be obvious from this that conversion to AC and back to DC is not a better solution. The DC/DC conversion would be much more efficient as only one active device is required.
 

ajdelange

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Serious question, since I'm not a battery or electrical guy. Would it be feasible to have the jerrycan DC charge the main battery instead, or would there be too much loss?
Yes, entirely feasible but there would be some attendant loss. Better to put it on the bus and let it deliver its energy directly to the load.
 

ajdelange

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Further to #50: Tesla has put Super Charger terminals on trailers and hauled to places where the utility is down e.g. parts of California blacked out during the fairly recent fire disaster. This would be an example where the battery in the vehicle is charged directly from the Jerry can (with the Jerry can being, in this case, presumably one of Tesla's larger (larger than a Powerwall, that is) battery storage products. I have no details on the interface between the batteries and charging terminals. As these trailers were ad hoc solutions to an immediate problem I imagine getting the gear together and into the field took precedence over maximizing efficiency.
 

Brian M

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180 pack R1S here also. Which means maybe 300mi range on the road if you're lucky. Same math as others 90%-10%, plus more loss if traveling over 70mph, cold weather, rain etc.... I have a Tesla now so I know the drill.
 

Jack99

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180 pack. Had a Tesla for 5 years and never was able to go more than 180-200 or so miles which was very frustrating. Agree at least in the cold (Northeast winters) 300 is far more realistic and I want as much range as possible.
 

outdoors_jp

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I'll be getting the 135 (as long as it's not too much more expensive). Need the 3rd row in the R1S to fit the family. Any guesses on the price increase between the batteries?
 

skyote

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I'll be getting the 135 (as long as it's not too much more expensive). Need the 3rd row in the R1S to fit the family. Any guesses on the price increase between the batteries?
They've announced that the previous starting prices of $69.5K/$72.5K will get you a well optioned 135.
 

ajdelange

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180 pack. Had a Tesla for 5 years and never was able to go more than 180-200 or so miles which was very frustrating. Agree at least in the cold (Northeast winters) 300 is far more realistic and I want as much range as possible.
That raises an interesting question in my mind. The Teslas have, of course, always had a heat pump (for A/C) but it was only with the Y that they started using it to pump heat into as well as out of the battery. Do the Rivian vehicles do this? If the answer is yes then I think you can expect noticeably better range performance relative to your 5 year old Tesla in winter even as "bad" as Boston's. The prairies of Canada may be a different story,

But in any case a 400 mile EPA rated vehicle is, practically speaking, a 320 mile vehicle even in summer. See No. 52.
 
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electruck

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That raises an interesting question in my mind. The Teslas have, of course, always had a heat pump (for A/C) but it was only with the Y that they started using it to pump heat into as well as out of the battery. Do the Rivian vehicles do this? If the answer is yes then I think you can expect noticeably better range performance relative to your 5 year old Tesla in winter even as "bad" as Boston's.
I wouldn't expect to find Tesla's octovalve but it sounds like Rivian has done something very similar in terms of optimizing thermal management and have a patent dating back to 2016 (provisional application).

Coolant loops

There is a single overall vehicle water-based liquid coolant system with at least two sub-loops and a grill-mounted radiator and fan, according to Richard Farquhar of Rivian.

A first sub-loop runs through and cools components like the motors and motor inverters. A second sub-loop runs through the battery pack.

Computer-controlled valves and replicated water pumps allow these loops to either operate separately or be joined together in order to exchange heat between the components and possibly the radiator.

For instance, although the battery pack has its own dedicated electric heater it can sometimes be effective and more efficient to share heat from the motors and motor inverters with the battery pack in cooler weather.

The battery pack loop also has a “chiller” connection to the air conditioning system to help cool the pack when it gets too hot. There is also apparently a heat exchange path that allows battery pack heat to help warm the vehicle cabin in addition to or instead of electric resistive heating.

A Rivian patent describes a similar system although it’s unclear how precisely this relates to the actual implementation used in Rivian’s initially announced vehicles.
 

ajdelange

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According to the patent they certainly have the ability to route heat from one place to another but I don't see the ability to reverse refrigerant flow and the air stream heat exchanger is labeled "condenser". The single TXV I find (I certainly didn't carefull pour over all those drawings) has a unidirectional flow arrow into a "chiller" and I can find no reversing valves. There is an electric battery heater (but you'd need that even with heat pumping for when the air is really cold). The text mentions that the approach is distinct from the usual one of extracting heat from air but at the same time does not preclude doing that. (a patent attorney once told me that the job of a Jedi patent lawyer is to claim as much as possible while revealing as little as possible).

So taking that patent as a guide it doesn't appear that they will be pulling heat from the air but then we don't know how similar the "embodiment" that will be delivered to us is to the patent.
 
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skyote

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I hope we hear more about the cold weather testing & details from the Long Way Up journey.

I don't care how they do it, as long as it's effective & efficient.
 

electruck

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According to the patent they certainly have the ability to route heat from one place to another but I don't see the ability to reverse refrigerant flow and the air stream heat exchanger is labeled "condenser". The single TXV I find (I certainly didn't carefull pour over all those drawings) has a unidirectional flow arrow into a "chiller" and I can find no reversing valves. There is an electric battery heater (but you'd need that even with heat pumping for when the air is really cold). The text mentions that the approach is distinct from the usual one of extracting heat from air but at the same time does not preclude doing that. (a patent attorney once told me that the job of a Jedi patent lawyer is to claim as much as possible while revealing as little as possible).

So taking that patent as a guide it doesn't appear that they will be pulling heat from the air but then we don't know how similar the "embodiment" that will be delivered to us is to the patent.
As I said, not Tesla's solution but Rivian has most definitely implemented some degree of thermal optimization.

While we do not know specifics of the production implementation, the patent does reference the cabin heat exchanger as a heat pump.
 
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