Testing the Rivian as a ‘backup’ power source

lefkonj

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It it’s well documented please provide sources. I have seen tests of it running power tools and other comparable loads so a small panel should be irrelevant if it is only pulling 500-800W.

I think it is useful to have this discussion for both my attempted use case or similar cases where people want to power a small camping adventure or tear drop
Rivian themselves have stated it isn't going to provide power to a house a large battery pack/generator. It is intended to power various power tools, and camping things but not a panel of household items. I understand you want this to happen but there are software issues they need to solve for this. I believe Lucid stated they will do this but it requires their charger hooked up to the car to provide power from the car to the house.

 
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jjswan33

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Rivian themselves have stated it isn't going to provide power to a house a large battery pack/generator. It is intended to power various power tools, and camping things but not a panel of household items. I understand you want this to happen but there are software issues they need to solve for this. I believe Lucid stated they will do this but it requires their charger hooked up to the car to provide power from the car to the house.
What your not getting is there is a difference to providing V2L or V2H directly from the CCS connector (ala Ford Lightning) and a power output on a truck (ala Ford Propower on board or whatever it is called).

For the first CCS connector V2H or V2L yes Rivian has said that will not be supported on current generation trucks. For the other it should and will support up to 1.5kW of load but what this thread and discussion has taught me is that my setup will not work like this.

Also it’s not that I want it to work like this but testing the boundaries of what it can and can’t do.
 

pc500

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Interesting thread. My question is whether anyone has tried powering a chest freezer or large refrigerator using the Rivian. If we have a multi-day power outage, I'd like to keep the contents of my freezer from thawing out. I'd also like to drive over to my friend's house and save their frozen food! It is the surge currents from the compressor, I am concerned about.
Should work fine, but use a power strip and extension cord not a panel.
 

pc500

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I'll say it again. It's not the load - it's the grounding. Use an isolation transformer and you'll be fine.

An interesting experiment would be to measure the voltage between the truck's ground pin and the transfer switch cable ground pin. Probably not 0.
Well at least there's hope that my use case will work... An RV electrical panel with a floating ground.
 

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The Transfer Switch manufacturer's official answer is on their web site. As suggested previously by others (Reliance gives a specific example) it's a GFCI trip - specifically due to parallel neutral paths due to bonded grounding at both ends.

NEC requires the neutral and earth ground to be bonded in the home's distribution panel. OSHA requires the neutral internally bonded to ground for job site generators. (I once saw a hard core plant safety supervisor shut down a contractor's generator because it did not meet this requirement). Rivian's inverter appears to be designed correctly to meet OSHA safety requirements for portable power.

In your installation, you have 120 volts on the black/hot wire, but a parallel path neutral splitting the current. The Rivian GFCI correctly sees a ground fault and trips. (Edited regarding voltage vs current).

Reliance has a newer series of transfer switch that also switches the neutral, eliminating the problem. Or if you are "Adventurous Forever" (pun intended) you could open up your Rivian inverter and try to defeat the internal bonding. Not recommended.

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Note that this panel is a double pole design (240 volts). The Rivian provides 120 volts. It should work fine with a 120 volt feed. Just ensure that the loads are connected to the correct side, and you'll only be able to use half the breaker space.
 
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zipzag

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Should work fine, but use a power strip and extension cord not a panel.
Yes, and alternating between powering the fridge and chest freezer should allow both units to keep sufficiently cool. A little home automation setup could even automate the switching.
 

ajdelange

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In your installation, you have 120 volts on the black/hot wire, but a parallel path neutral with ~60 volts on the neutral and ~60 volts on the ground. The Rivian GFCI correctly sees a ground fault and trips.
A generator (which the Rivian mimics) used in the field should have neutral and frame (earth/ground) bonded at the generator and the frame connected to a proper grounding system (ground rod for a generator; the truck's grounding system for the truck).

A builiding must have the earth and neutral bonded and when a generator is connected to it the bond at the generator must be removed. If it is not neutral load current can divide between the neutral wire and the ground wire. It is in parallel with the neutral wire as the two are connected at each end. Note carefully here that it is CURRENT which divides. NOT voltage. Thus you would, using ground as a reference, have 120VAC on the hot wire and 0 volts on each of the neutral and green/bare wires but were the current 10A in the hot wire it could be, for example, 8A in the white and 2A in the ground wire. As I explained in an earlier post, load current flowing in a grounding conductor is deemed "objectionable" as it defeats the purpose of the ground.

The way around this is to have a "separately derived system" which can be achieved either by switching the neutral (3 pole transfer switch) or the use of an isolation transformer.

The way to make the Rivian (and Ford) system feed a whole house is to "derive" the neutral from the vehicle when in this mode i.e. disconnect it from the vehicle ground. That's why it worls with the Yeti. The Yeti doesn't have a system ground.
 
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Zoidz

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A generator (which the Rivian mimics) used in the field should have neutral and frame (earth/ground) bonded at the generator and the frame connected to a proper grounding system (ground rod for a generator; the truck's grounding system for the truck).

A builiding must have the earth and neutral bonded and when a generator is connected to it the bond at the generator must be removed. If it is not neutral load current can divide between the neutral wire and the ground wire. It is in parallel with the neutral wire as the two are connected at each end. Note carefully here that it is CURRENT which divides. NOT voltage. Thus you would, using ground as a reference, have 120VAC on the hot wire and 0 volts on each of the neutral and green/bare wires but were the current 10A in the hot wire it could be, for example, 8A in the white and 2A in the ground wire. As I explained in an earlier post, load current flowing in a grounding conductor is deemed "objectionable" as it defeats the purpose of the ground.

The way around this is to have a "separately derived system" which can be achieved either by switching the neutral (3 pole transfer switch) or the use of an isolation transformer.

The way to make the Rivian (and Ford) system feed a whole house is to "derive" the neutral from the vehicle when in this mode i.e. disconnect it from the vehicle ground. That's why it worls with the Yeti. The Yeti doesn't have a system ground.
Yes, I was thinking about a possible current imbalance and typing faster than thinking, current is divided @120v.
 

pc500

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Yes, and alternating between powering the fridge and chest freezer should allow both units to keep sufficiently cool. A little home automation setup could even automate the switching.
Both can probably run at once. They don't take that much power.
 

zipzag

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Both can probably run at once. They don't take that much power.
The risk is simultaneous compressor start that trips the breaker. This will, of course, happen at 11pm and go unnoticed.
 

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One hacky solution to this grounding issues, and a way to still keep it clean without changing your current setup might be to:
- Pick up a battery generator that you can charge to full capacity and set aside for power outages
- When power goes out, use the battery generator to power the house, but also plug the generator into the R1T bed to keep the battery generator charged. I doubt the discharge/charge curve will be close, but that might give you an extra hour of use out of your generator since you're simultaneously charging the battery generator.

Of course you'll want to look for a battery generator that is capable of being charged as it's dispensing power ...

Your original problem is almost certainly a grounding "feature" that doesn't like seeing the ground from the panel as it's not going to be the same as the ground at the truck. That makes sense why it cuts off immediately. Otherwise it would cut off after a few seconds if it was load related.
 
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jjswan33

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One hacky solution to this grounding issues, and a way to still keep it clean without changing your current setup might be to:
- Pick up a battery generator that you can charge to full capacity and set aside for power outages
- When power goes out, use the battery generator to power the house, but also plug the generator into the R1T bed to keep the battery generator charged. I doubt the discharge/charge curve will be close, but that might give you an extra hour of use out of your generator since you're simultaneously charging the battery generator.

Of course you'll want to look for a battery generator that is capable of being charged as it's dispensing power ...

Your original problem is almost certainly a grounding "feature" that doesn't like seeing the ground from the panel as it's not going to be the same as the ground at the truck. That makes sense why it cuts off immediately. Otherwise it would cut off after a few seconds if it was load related.
Yes. I have what you describe now. My GZ with 6kWh of battery can handle the backup by itself for at least a day. The 600W charger I have for the GZ works fine on the truck, with an average draw that is likely less than 600W with my 4 backed up circuits. I bet I could survive a power outage of a week or so without recharging the truck.
 

trez63

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Yes. I have what you describe now. My GZ with 6kWh of battery can handle the backup by itself for at least a day. The 600W charger I have for the GZ works fine on the truck, with an average draw that is likely less than 600W with my 4 backed up circuits. I bet I could survive a power outage of a week or so without recharging the truck.
Honestly this is a better setup IMO than plugging the truck directly to the panel. Because this way you can drive away without having to unplug the house. Do you have a link to the unit you’re using now? I’m considering buying something to use and then only using my gas generator when it runs down. Or perhaps in the case of multi day outages, I can use the battery at night and the gas generator during the day to avoid noise issues.
 

ajdelange

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One hacky solution to this grounding issues, and a way to still keep it clean without changing your current setup might be to:
-routages
[s/QUOTE]
Yes, that will work. I ran my garage that way last summer while waiting for delivery of my Powerwalls. Primary source in this case was an extension cord from the main building to the Yeti power supply. As long as the average draw from the garage was less than the ~400W rate at which the Yeti power supply can charge the battery pack (and it was - workmen's tools,, garage door openers, net gear, lights...) all was good. Issues here were isolating the garage neutral/ground from the main building neural/ground and getting 240 from the Yeti (autotransformer).
 
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jjswan33

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Honestly this is a better setup IMO than plugging the truck directly to the panel. Because this way you can drive away without having to unplug the house. Do you have a link to the unit you’re using now? I’m considering buying something to use and then only using my gas generator when it runs down. Or perhaps in the case of multi day outages, I can use the battery at night and the gas generator during the day to avoid noise issues.
Yeah good point, also my GZ has a 2000W inverter so a little more robust if I want to run any kitchen appliances.

I have the Yeti 6000X which is their largest (and most expensive). They have a number of smaller ones as well:

https://www.goalzero.com/shop/portable-power/

I do love mine for it's main purpose (powering my camper van). You might also check out some competitor products if you really want to go that route:

https://www.bluettipower.com/
https://bigbattery.com/
https://us.ecoflow.com/

They all have some different features and advantages/disadvantages, and I am sure their are other systems as well. Keep in mind if you charge one of these VIA renewable sources it would qualify as home battery storage and be eligible for a federal tax credit.
 

 
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