[Bob O'Connor]

Rivian has tweeted that both the R1T and R1S can be flat towed behind a motorhome. I assume they freewheel to lower drag. I have also read that you can charge the batteries while towing. In the only reference to tow charging I have seen the person doing the charging said she had to put the R1T in reverse and step on the accelerator to get a charge. This obviously won't work behind a motorhome. I'm hoping it will recharge using the regeneration of the vehicle. Which brings up another possible problem. I have a golf cart with regeneration, but when fully charged at home then going downhill to the golf course it would overcharge and lock up until it cooled down. I installed a heatsink, that solved the problem in the golf cart but that was only a quarter mile distance. With the Rivian I will be towing for many miles so it would need a system to cancel the charging setting when fully charged.

Let's throw in another Question on towing. Can the Rivian be wired to apply brakes when the motorhome brakes (required in some states)?

 

[azbill]

Rivian has tweeted that both the R1T and R1S can be flat towed behind a motorhome. I assume they freewheel to lower drag. I have also read that you can charge the batteries while towing. In the only reference to tow charging I have seen the person doing the charging said she had to put the R1T in reverse and step on the accelerator to get a charge. This obviously won't work behind a motorhome. I'm hoping it will recharge using the regeneration of the vehicle. Which brings up another possible problem. I have a golf cart with regeneration, but when fully charged at home then going downhill to the golf course it would overcharge and lock up until it cooled down. I installed a heatsink, that solved the problem in the golf cart but that was only a quarter mile distance. With the Rivian I will be towing for many miles so it would need a system to cancel the charging setting when fully charged.

Let's throw in another Question on towing. Can the Rivian be wired to apply brakes when the motorhome brakes (required in some states)?

When an EV is fully charged the regen is automatically disbled to prevent overcharging. My Bolt has a display to show when it is enabled and disabled. It typically enables at about 95% charge or less.

 

[Bob O'Connor]

When an EV is fully charged the regen is automatically disbled to prevent overcharging. My Bolt has a display to show when it is enabled and disabled. It typically enables at about 95% charge or less.

Thank you azbil for your quick response. I assumed there was a simple way, but you know what happens when you assume LOL.

 

[eHauler]

@Bob O'Connor hard to say what Rivian included to sync brake functions till they release more. The bed does have a lot of external functions built in and its possible that necessary connections like that are part of it. Have you asked Rivian's Customer Service team?

 

[Wildabeest]

I can’t imagine that the extra load put onto your tow vehicle will very good for its performance or longevity. Having regen activated while flat towing is going to be like trying to flat tow a vehicle with the parking brake partially engaged. Just doesn’t seem like a good idea to me.

 

[eHauler]

@Bob O'Connor, I reached out to Rivian's support team and this is what I got back.

"I did find that the Rivian vehicle being towed would not be able to use regenerative breaking as a trailer brake, and that the vehicle being towed cannot function as brake lights.

I don't have anything that specifically mentions being wired to apply the brakes simultaneously with the motorhome, but I did reach out to our teams to see if they can help provide any extra insight on that."

They will be following up with me sometime soon as you could probably tell by now.
Will keep you and everyone else posted!

 

[Bob O'Connor]

I can’t imagine that the extra load put onto your tow vehicle will very good for its performance or longevity. Having regen activated while flat towing is going to be like trying to flat tow a vehicle with the parking brake partially engaged. Just doesn’t seem like a good idea to me.

I'm sure you are right, but that brings us to my idea. Bear with me I may be way out in left field. Since the regen system acts like a brake would it be possible to have the regen engage when the motorhome brakes are applied and release when the motorhome brakes are released? Power for brakes on a regular tow vehicle react that way. This would be a win win by slowing the vehicles and getting a small recharge at the same time. Taking this line of thinking one step further, how about a remote activation (from the cab of the motorhome) of the regen for long downhill sections of road, it would save the motorhome brakes and again get a recharge. I'm sure the tech and electronic geniuses at Rivian can figure a way to do it, I just don't know if there are enough people interested in such a program to make them feel the need to develop it. Maybe I'm the only customer who wants to tow my R1T. Most states have a requirement that the towed vehicle have brakes as well as lights so some type of braking system is needed anyway.

 

[Bob O'Connor]

@Bob O'Connor, I reached out to Rivian's support team and this is what I got back.

"I did find that the Rivian vehicle being towed would not be able to use regenerative breaking as a trailer brake, and that the vehicle being towed cannot function as brake lights.

I don't have anything that specifically mentions being wired to apply the brakes simultaneously with the motorhome, but I did reach out to our teams to see if they can help provide any extra insight on that."

They will be following up with me sometime soon as you could probably tell by now.
Will keep you and everyone else posted!

boy you are quick.I didn't even finish my last query before you posted an answer. (which I hope will change LOL)

 

[Bob O'Connor]

I don't know for sure but I assume the R1T and R1S have regular brakes. Without getting too fancy I can have brake and lights hooked up like I have on my Honda. I was just hoping to kill two birds with one stone so to speak.

 

[Bob O'Connor]

While on the subject of towing, does anyone know how the tow hooks are mounted to the front of the R1T. It should be a strong point of attachment and I thought if I removed the hooks that might be a good place to put the tow bar attachment hardware. Your thoughts?

 

[eHauler]

@Bob O'Connor, Amanda from Rivian Customer Service got back to me. Still not the exact information we're after but she will be reaching out to other teams to see what they can provide. As soon as I get that, it will be posted here.

"Thanks for taking the time to chat with me earlier about the tow braking for behind your motorhome. Unfortunately, I wasn't able to find any additional information on if the vehicle could be wired to brake simultaneously with your motorhome. I did pose this question to our internal teams so they can make sure it's addressed and can be shared once that information becomes available.

If I do find anything else out on the subject I'll be sure to reach out and let you know!"

 

[Bob O'Connor]

@Bob O'Connor, Amanda from Rivian Customer Service got back to me. Still not the exact information we're after but she will be reaching out to other teams to see what they can provide. As soon as I get that, it will be posted here.

"Thanks for taking the time to chat with me earlier about the tow braking for behind your motorhome. Unfortunately, I wasn't able to find any additional information on if the vehicle could be wired to brake simultaneously with your motorhome. I did pose this question to our internal teams so they can make sure it's addressed and can be shared once that information becomes available.

If I do find anything else out on the subject I'll be sure to reach out and let you know!"

Thanks

 

[Heyvernsky]

Rivian has tweeted that both the R1T and R1S can be flat towed behind a motorhome. I assume they freewheel to lower drag. I have also read that you can charge the batteries while towing. In the only reference to tow charging I have seen the person doing the charging said she had to put the R1T in reverse and step on the accelerator to get a charge. This obviously won't work behind a motorhome. I'm hoping it will recharge using the regeneration of the vehicle. Which brings up another possible problem. I have a golf cart with regeneration, but when fully charged at home then going downhill to the golf course it would overcharge and lock up until it cooled down. I installed a heatsink, that solved the problem in the golf cart but that was only a quarter mile distance. With the Rivian I will be towing for many miles so it would need a system to cancel the charging setting when fully charged.

Let's throw in another Question on towing. Can the Rivian be wired to apply brakes when the motorhome brakes (required in some states)?

I asked RJ that same question
He answered we are looking into it
Or something like that

 

[Middlefork]

We're planning to tow a travel trailer with the R1T but are newbies at towing. Do you think there might be a way to charge the Rivian from the trailer battery. We'll have solar power on the trailer but obviously wouldn't want to totally discharge the trailer battery.

 

[CommodoreAmiga]

We're planning to tow a travel trailer with the R1T but are newbies at towing. Do you think there might be a way to charge the Rivian from the trailer battery. We'll have solar power on the trailer but obviously wouldn't want to totally discharge the trailer battery.

Are you talking about a typical trailer with one or a few deep cycle lead acid batteries? No, you wouldn't want to charge your Rivian from that.

 

[Middlefork]

Are you talking about a typical trailer with one or a few deep cycle lead acid batteries? No, you wouldn't want to charge your Rivian from that.

We'd be using lithium batteries, 390 Ah total.

 

[CommodoreAmiga]

We'd be using lithium batteries, 390 Ah total.

390Ah at 12V is only 4.68 kWh. You're not charging your Rivian from that!

 

[Middlefork]

That's what I needed to know. Thanks for your help!!

 

[timesinks]

It's not totally impossible, though it may be mostly impractical. It depends on 1) how much solar is on your roof (and how good your solar exposure is), 2) whether you can configure the Rivian charge rate when using the portable EVSE, and 3) whether your inverter is sized to handle that load.

We have 900W of solar panels on our Sprinter build feeding a 400Ah LiFePO4 bank and a 2000W inverter. Since our panels are flat on the roof (and not angled toward the sun), in ideal conditions, we get more like 700W of power into our system. If the Rivian lets you throttle the charge current to 5 or 6A, you could absolutely send some excess energy to the truck during the day time from our system. We've charged our Volt at 8A before (it is only configurable as 12A or 8A when charging at Level 1)... mostly to say we'd done it, not because it was particularly practical.

The size of your bank helps smooth out unevenness in solar energy (the most obvious example being at night), but what you really care about is that steady mid-day sun and how much energy you can generate in excess of what you drew from your bank overnight.

600W into the truck for 6 hours is 3.6kWh or about 8 miles of range per day at the anticipated consumption levels. If you're camped out somewhere and just need to run into town every few days, it could offset that. Or just be some free energy. But it's not going to provide a meaningful dent in terms of energy needed to tow that trailer from point A to point B. I wouldn't build a system just with an EV in mind, but if I wanted a high-end off-grid electrical system on a camper anyways, I'd consider sizing it up to at least have some flexibility.