R1S flat towing behind an RV?

[ajdelange]

Where would the energy for the regen come from if not the towing vehicle?

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[DucRider]

Where would the energy for the regen come from if not the towing vehicle?

If the regen occurred only when the towing vehicle would be slowing/braking, it would not adversely impact fuel economy (or at least no more so than the act of towing)

 

[skyote]

If the regen occurred only when the towing vehicle would be slowing/braking, it would not adversely impact fuel economy (or at least no more so than the act of towing)

Exactly, and many states require auxiliary braking for towables, so to have this integrated would be awesome, not to mention the ability to capture some of that energy by regen.

 

[ajdelange]

Battery charging while towing would be great as long as it doesn't drag down my RV's performance too much. If supported, it would be a great idea to have the ability to disable it.

This is what I was responding to. The man posing the question seems to be thinking "If I had this I could tow my R1T to the campsite (and charge it on the way), make day trips from the campsite etc. and recharge it while towing to the next campsite etc. Never have to visit a charger!". Now that is true. But what an inefficient way to charge (both in terms of the energy used and the pollutants created). See some of the videos on charging BEVs with generators. This is, in effect, what you would be doing. You have an ICE engine (with its Carnot losses) coupled by a belt (the roadway) to the generator in the R1T. I estimate that it costs me about $2 per kWh to charge my X from my generator (compare to $0.25 kWh from a supercharger).

It should also be very clear that this generator (4 generators in the case of the R1T) is a load on the RV engine in addition to the loads it is already experiencing. It will, thus, increase the fuel consumption and reduce the mpg and range available from a tankful.

If the regen occurred only when the towing vehicle would be slowing/braking, it would not adversely impact fuel economy (or at least no more so than the act of towing)

Well true enough. It would actually improve the overall system (the 2 vehicle fleet) efficiency as using the Rivian as the RVs dynamic braking system would save some of the energy normally dissipated in the RV brakes for later use in the Rivian. But that "if" is a pretty big word as a robust interface between Rivian and RV would be required. While its an interesting idea I don't think it is
1)What the poser of the question wanted to know
2)Likely to be possible with early versions of the Rivians

Note that railways use such a system. Batteries in railcars are charged by generators tied to the wheels. The rail is used as a means of transferring power from the locomotive to cars located anywhere in the string.

 

[CappyJax]

Note that railways use such a system. Batteries in railcars are charged by generators tied to the wheels. The rail is used as a means of transferring power from the locomotive to cars located anywhere in the string.

No, that is not how diesel electric trains work at all.

 

[StevieD]

This is what I was responding to. The man posing the question seems to be thinking "If I had this I could tow my R1T to the campsite (and charge it on the way), make day trips from the campsite etc. and recharge it while towing to the next campsite etc. Never have to visit a charger!". Now that is true. But what an inefficient way to charge (both in terms of the energy used and the pollutants created). See some of the videos on charging BEVs with generators. This is, in effect, what you would be doing. You have an ICE engine (with its Carnot losses) coupled by a belt (the roadway) to the generator in the R1T. I estimate that it costs me about $2 per kWh to charge my X from my generator (compare to $0.25 kWh from a supercharger).

It should also be very clear that this generator (4 generators in the case of the R1T) is a load on the RV engine in addition to the loads it is already experiencing. It will, thus, increase the fuel consumption and reduce the mpg and range available from a tankful.



Well true enough. It would actually improve the overall system (the 2 vehicle fleet) efficiency as using the Rivian as the RVs dynamic braking system would save some of the energy normally dissipated in the RV brakes for later use in the Rivian. But that "if" is a pretty big word as a robust interface between Rivian and RV would be required. While its an interesting idea I don't think it is
1)What the poser of the question wanted to know
2)Likely to be possible with early versions of the Rivians

Note that railways use such a system. Batteries in railcars are charged by generators tied to the wheels. The rail is used as a means of transferring power from the locomotive to cars located anywhere in the string.

Actually, I prefer braking via Air Force One system to maintain braking capability under all conditions as well as less potential enforcement problems. My comment basically meant to say that charging is a nice idea as long as I am able to disable it. I need compatible braking much more than I need charging as I’ll be weighing in over 50,000 pounds.

 

[CappyJax]

Actually, I prefer braking via Air Force One system to maintain braking capability under all conditions as well as less potential enforcement problems. My comment basically meant to say that charging is a nice idea as long as I am able to disable it. I need compatible braking much more than I need charging as I’ll be weighing in over 50,000 pounds.

An electric brake controller is probably all that you would need. I am sure Rivian has looked into how to make it very compatible with current brake controllers. If you could use the Rivian to slow your RV, especially on long downhill runs, you could get a lot of recharging of the battery.

 

[ajdelange]

I don't think you will be towing 50,000 pounds with an R1T.

 

[electruck]

I don't think you will be towing 50,000 pounds with an R1T.

No, the R1T would be the TOAD behind his RV. I believe he was referring to their combined weight to provide some perspective on his total braking requirement.

 

[ajdelange]

Doh!

 

[StevieD]

An electric brake controller is probably all that you would need. I am sure Rivian has looked into how to make it very compatible with current brake controllers. If you could use the Rivian to slow your RV, especially on long downhill runs, you could get a lot of recharging of the battery.

Brake controllers are ok when I pull a trailer but I want better control with a TOAD. Air Force One type systems connect to my RV air brake system and provides proportional braking. After 40 some years of RV experience using various types of braking systems, this has given me the best performance. In fact, Spartan chassis, a major RV diesel chassis provider now includes Air Force One components.
In the case of my RAM toad, the onboard components supply vacuum for the power brake booster and proportionately brakes using a small piston and cable connected to the brake pedal.

 

[StevieD]

No, the R1T would be the TOAD behind his RV. I believe he was referring to their combined weight to provide some perspective on his total braking requirement.

CORRECT. I intend to drive my 45 foot RV with the R1T connected behind it (My Toad).

 

[CappyJax]

Brake controllers are ok when I pull a trailer but I want better control with a TOAD. Air Force One type systems connect to my RV air brake system and provides proportional braking. After 40 some years of RV experience using various types of braking systems, this has given me the best performance. In fact, Spartan chassis, a major RV diesel chassis provider now includes Air Force One components.
In the case of my RAM toad, the onboard components supply vacuum for the power brake booster and proportionately brakes using a small piston and cable connected to the brake pedal.

Something like this is all you need.

https://www.etrailer.com/Trailer-Br...-N085niz9B_XmDIhA-adChhIQ6kVWXJkaAn4iEALw_wcB

 

[skyote]

I need compatible braking much more than I need charging as I’ll be weighing in over 50,000 pounds.

Wow, that's quite a load!

 

[StevieD]

Something like this is all you need.

https://www.etrailer.com/Trailer-Br...-N085niz9B_XmDIhA-adChhIQ6kVWXJkaAn4iEALw_wcB

https://www.demco-products.com/rv-t...sF6GMao-BQJ90TyqFk_D_zdgFsfQEM_oaAiFlEALw_wcB

I’ve used this on more than 3 RVs I’ve owned and many TOADS including Jeeps, Toyota Tundra, Scion, and Ram 1500. Very satisfied with their operation. Previously, I’ve used different systems on some of my other RVs and Toads. I hope that Rivian will describe this feature in more detail soon.

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