Used Cybertruck to power my house during power outage

[LexusCyber]

My CT hadn't been home 24 hours before our power went out due to a big storm.

I have a cutoff switch with a NEMA 14-50 plug that I usually plug into an ICE generator during power outages. This time I plugged into the CT, turned it on with the app and "no fuss, no muss" the house had power, including the well. It used about 1% per hour through the evening.

We have propane for hot water and heater and, except for the refrigerator, we didn't run our appliances much. Not hearing the generator is delightful. It did turn off after about 10 hours, don't know why, and I turned it back on from the app without any drama.

My granddaughter wanted me to drive her to High School today (lots of heads turned) so I topped up at a supercharger before coming home (power is still out here) so I'm set for the next couple of days if necessary.

powerful!

this is a feature worth big $$$$! people are not used with having this possibility but sure enough they will appreciate the value proposition once they get to use it even ONCE. thank you for sharing.

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[Woodrick]

We have propane for hot water and heater and, except for the refrigerator, we didn't run our appliances much. Not hearing the generator is delightful. It did turn off after about 10 hours, don't know why, and I turned it back on from the app without any drama.

Make sure that you check the time period recommendations for oil changes. And the oil level/pressure while running.
A 10-hour run time is probably enough to need a maintenance anyway.

You may be able to check the logs on the unit to determine the shutdown reason.

 

[MountainRatMatt]

Make sure that you check the time period recommendations for oil changes. And the oil level/pressure while running.
A 10-hour run time is probably enough to need a maintenance anyway.

You may be able to check the logs on the unit to determine the shutdown reason.

Yes, always check the oil in your Cybertruck.

 

[CyberGus]

Yes, always check the oil in your Cybertruck.

 

[whiffleballpractice]

I charged my Tesla on a family members NEMA 14-50 a while back and multi-meter tested it before I used it. The neutral wasn't connected even but ground was. Vehicle charged fine. AFAIK, the neutral in a 240v connection like for appliances are for when they have some elements using 240v (hot & hot) and others in that appliance using 120v (hot & neutral) .

Interestingly this product has an EV charging mode that binds the neutral+ground.

Seems like you've got it figured out, but like @Woodrick said, this is NOT true for the case of powering your house from anything acting as a generator; your house 100% needs the neutral to be present.

 

[whiffleballpractice]

Providing some lessons learned from folks that have done this with their Lightning and the powerboost before it (assuming the same issues apply)...

The Cybertruck SHOULD be configured as a "separately derived system" (the same thing as a portable generator) because that is the NEC guidance. What this means is that the neutral from the truck's plug is bonded to the truck's ground. This is an electrical safety issue and it seems a few here are familiar with it in the context of some EV chargers detecting when the bond isn't present and disabling. The issue that follows this is that neutral and ground are supposed to be bonded in exactly one place in an overall system, and your neutral and ground in your home are typically bonded at the service entrance.

If you connect your truck to a generator inlet and use an interlock as suggest this thread and Tesla configured the Cybertruck as described above, there will be 2 neutral ground bonds in the system. This will only be an issue for the Cybertruck if Tesla configured it to detect this issue and shutdown if it detects it. On the Fords, this shows up as a ground fault and shuts off the power.

The most correct solution to this is to use a transfer switch panel that is meant for portable generators, like this one: https://www.generac.com/all-product...witches/homelink-50a-transfer-switch-aluminum

A sketchier solution is to not connect the truck's ground via the cable to your inlet/panel. There is a lot of disagreement over whether this is safe or not. I don't suggest it, but I'm not going to argue about it.

 

[scottf200]

Seems like you've got it figured out, but like Woodrick said, this is NOT true for the case of powering your house from anything acting as a generator; your house 100% needs the neutral to be present.

Indeed as I said 120v uses the neutral.

 

[pschmitz87]

I think this is an appropriate thread to ask this question but any mods let me know if it makes more sense to break this off into a separate thread.

Currently we have 2x Powerwalls installed and a Gen 2 Tesla Charger. I spoke to our Solar company that installed everything and with the new Universal Charger that comes free with the Foundation Edition, they just need to swap the chargers to enable the V2H feature of the CT.

I've seen a few different reports and numbers of how long a CT is supposed to power a house, but is it reasonable to assume that since our 2x powerwalls offer 27kwh of energy and the CT has 123kwh, is that effectively adding 4+ times what we have right now in capacity?

I'm sure there is a simple EE answer to this but I've seen other posts talk about how it can only add like 30 hours of power to a typical house's electrical pull but that doesn't seem right when comparing it to the hours we get out of our powerwalls.

Any insight is greatly appreciated, thanks!

 

[Woodrick]

I think this is an appropriate thread to ask this question but any mods let me know if it makes more sense to break this off into a separate thread.

Currently we have 2x Powerwalls installed and a Gen 2 Tesla Charger. I spoke to our Solar company that installed everything and with the new Universal Charger that comes free with the Foundation Edition, they just need to swap the chargers to enable the V2H feature of the CT.

I've seen a few different reports and numbers of how long a CT is supposed to power a house, but is it reasonable to assume that since our 2x powerwalls offer 27kwh of energy and the CT has 123kwh, is that effectively adding 4+ times what we have right now in capacity?

I'm sure there is a simple EE answer to this but I've seen other posts talk about how it can only add like 30 hours of power to a typical house's electrical pull but that doesn't seem right when comparing it to the hours we get out of our powerwalls.

Any insight is greatly appreciated, thanks!

You are mixing "typical" and reality. And you are assuming that the Cybertruck will let you have all 123 kWH. And you are probably mixing power augmentation / shifting with power failure.

Tesla doesn't recommend that the Cybertruck doesn't normally charge to above 80% capacity. And you probably want a lower cap, just in case you have to use the truck.

Reports of how long it can power a house have nothing to do with you. Your house isn't like any other house and the range can vary from a few hours to weeks in reality.

Powerwalls are often used for energy shifting, but they can be used for power failure. The Cybertruck won't be able to energy shift.

 

[Crissa]

PS:

A Tesla and most car chargers don't use neutral when charging at L2.

Heck, my Zero doesn't even have a place to connect neutral. Two opposing hots and a ground, just like a NACS or J1772.

-Crissa

PS: How long it can support your house varies on how much energy you're using. If it's cold or hot, you'll be using more power to keep the house a decent temperature. If it's not, you won't be.

My 3kW battery can:

• Run fridge/gas range/internet for 24 hours
• Run all that and the entertainment system for 8 hours
• or run a space heater for 2 hours

It's all a choice of what you're doing, what you need to do, etc.

 

[pschmitz87]

You are mixing "typical" and reality. And you are assuming that the Cybertruck will let you have all 123 kWH. And you are probably mixing power augmentation / shifting with power failure.

Tesla doesn't recommend that the Cybertruck doesn't normally charge to above 80% capacity. And you probably want a lower cap, just in case you have to use the truck.

Reports of how long it can power a house have nothing to do with you. Your house isn't like any other house and the range can vary from a few hours to weeks in reality.

Powerwalls are often used for energy shifting, but they can be used for power failure. The Cybertruck won't be able to energy shift.

But in theory, lets say I have my cybertruck plugged in to my wall and its at 100% charge and the power goes out in my home. Is the basic math that my house capacity is basically the 27kwh from the powerwalls plus the 123kwh from the truck? or even lets assume the truck doesn't allow that feature below 10%, then can I still add 110kwh to the total?

I just didn't know if the powerwalls offer electricity at different voltage/amp rates then the car so its not an apples to apples comparison with how long our house can currently last on the batteries.

 

[pschmitz87]

PS:

A Tesla and most car chargers don't use neutral when charging at L2.

Heck, my Zero doesn't even have a place to connect neutral. Two opposing hots and a ground, just like a NACS or J1772.

-Crissa

PS: How long it can support your house varies on how much energy you're using. If it's cold or hot, you'll be using more power to keep the house a decent temperature. If it's not, you won't be.

My 3kW battery can:

• Run fridge/gas range/internet for 24 hours
• Run all that and the entertainment system for 8 hours
• or run a space heater for 2 hours

It's all a choice of what you're doing, what you need to do, etc.

Yeah that's fair, I was more trying to calculate in my head if our Powerwalls currently keep the house on for 12 hours with 27kwh can I now expect roughly 48 if the truck was plugged in at 100% when the power goes out. More just trying to justify part of the price vs adding more powerwalls to our home set up.

 

[Woodrick]

But in theory, lets say I have my cybertruck plugged in to my wall and its at 100% charge and the power goes out in my home. Is the basic math that my house capacity is basically the 27kwh from the powerwalls plus the 123kwh from the truck? or even lets assume the truck doesn't allow that feature below 10%, then can I still add 110kwh to the total?

I just didn't know if the powerwalls offer electricity at different voltage/amp rates then the car so its not an apples to apples comparison with how long our house can currently last on the batteries.

The truck offers electricity at 240 and 120V. Those are what you house uses.

The Cybertruck doesn't offer direct access to the batteries though.

 

[Cybertruck 1974]

Yeah that's fair, I was more trying to calculate in my head if our Powerwalls currently keep the house on for 12 hours with 27kwh can I now expect roughly 48 if the truck was plugged in at 100% when the power goes out. More just trying to justify part of the price vs adding more powerwalls to our home set up.

so worth it. 10 powerwalls will cost 100k. So having a kick ass truck and 10 powerwalls worth of power for 100k hands down is 100% the way to go.

 

[pschmitz87]

The truck offers electricity at 240 and 120V. Those are what you house uses.

The Cybertruck doesn't offer direct access to the batteries though.

Hey W, I think maybe I didn't write my original message very clearly, apologies about that. Let me take a step back with my understanding of how V2H charging works with the CT to make sure I didn't misinterpret.

My understanding is there are 2x main ways the CT Powershare feature (https://www.tesla.com/powershare) can charge a home. Including the link more for reference for others not implying you didn't know about it and also because its incredible hard to find easily on the website.

1. Is by plugging your home's generator or other non-Tesla equipment directly into the 120V and 240V ports in the bed of the truck. This essentially turns your Tesla into a standard power source and should be compatible with any equipment that has a cord with a male plug on the end to draw power from.

2. Is through the NACS port where you plug the Tesla Universal Wall charger into the CT's NACS charging port and as long as you have a Tesla Gateway 3V or newer, then if the Gateway detects the grid is down it can intelligently pull power from the CT to be the home's source of energy until either the grid is detected to come back online or the CT runs out of battery (or potentially it stops at 10% so your truck doesn't completely die)

If you also look into the fine print in the site above, it claims halfway down the page that the CT can power a home for 3x days but at the very bottom of the page it notes that is based on 30kwh of energy use per day so even by those metrics, that would mean it would only be the equivalent of 90kwh right? Or potentially is that just the point it stops providing power so the truck doesn't completely die?

I know this thread started as Johnm6875 discussing leveraging option #1 above but my question is for option #2.

I hope that helps to clarify what data I'm after in terms of how this can augment the current Gateway + 2x powerwall setup I currently have at our house. Let me know if you think this deserves or should have its own thread so it doesn't fork the conversation for this one.

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