Using an EV for backup power in case of power outage

[BeerParty]

There have been several discussions in the Scout forums about using the Scouts as backup power during a power outage. I wanted to share some of my information so people have some real data to use if they are planning for this. Note that the data is specific for my house - but you should be able to extrapolate for your own situation.

I have a transfer switch installed on my house so I can safely power my critical circuits during a power outage. The following are attached to those circuits:

• well pump (240V 30amp circuit)
• heat and hot water (propane tank-less system, so just a 15amp circuit for the electronics)
• kitchen refrigerator/freezer
• basement upright freezer
• cable router
• miscellaneous lights

I have a Delta Pro 3 to use as my primary backup power supply. I selected this unit because it has a 240V output I can plug into the transfer switch; the DP3 will provide split phase 240V power for my well pump. The DP3 also allows me to plug in a 120V source to recharge the battery while it is providing 240V output, so I can recharge the DP3 while still providing power to the house via the transfer switch. During an extended outage I can use the V2L adapter I have for my Hyundai Ioniq 5 to recharge the DP3 when necessary.

I tested all this a few days ago. I connected the DP3 to the transfer switch and switched over to using it for power. I ran the the DP3 for 3 hours. During that time I ran a hot shower for 10 minutes, ran the heat (it's wintertime in NH, temps were just above freezing), flushed the toilets, opened the fridge/freezer doors, connected to the internet (router), and used the lights intermittently. After three hours the DP3 had used ~15% of it's available power (90% to 75%). I then connected the Hyundai Ioniq 5 V2L adapter and plugging in the DP3. The DP3 ran the house loads and recharged to 90% in less than 30 minutes.

The DP3 has a 4 kWh battery. With an average of about 15% for 3 hours, the DP3 would last about 18 hours by itself (using 90% of the total capacity). Another way of looking at it - my house used about 0.2 kW per hour. My 2024 Hyundai Ioniq 5 has a battery capacity of 74 kWh (usable). Even if I only use 50% of that (37 kWh) for backup power, my HI5 can provide about 185 hours (>7 days) of backup power for my house.

For reference (source):

• the Scout Harvester will have a 60-70 kWh battery
• the Scout BEV will have a 120-130 kWh battery

 

[dreamweaver]

There have been several discussions in the Scout forums about using the Scouts as backup power during a power outage. I wanted to share some of my information so people have some real data to use if they are planning for this. Note that the data is specific for my house - but you should be able to extrapolate for your own situation.

I have a transfer switch installed on my house so I can safely power my critical circuits during a power outage. The following are attached to those circuits:

• well pump (240V 30amp circuit)
• heat and hot water (propane tank-less system, so just a 15amp circuit for the electronics)
• kitchen refrigerator/freezer
• basement upright freezer
• cable router
• miscellaneous lights

I have a Delta Pro 3 to use as my primary backup power supply. I selected this unit because it has a 240V output I can plug into the transfer switch; the DP3 will provide split phase 240V power for my well pump. The DP3 also allows me to plug in a 120V source to recharge the battery while it is providing 240V output, so I can recharge the DP3 while still providing power to the house via the transfer switch. During an extended outage I can use the V2L adapter I have for my Hyundai Ioniq 5 to recharge the DP3 when necessary.

I tested all this a few days ago. I connected the DP3 to the transfer switch and switched over to using it for power. I ran the the DP3 for 3 hours. During that time I ran a hot shower for 10 minutes, ran the heat (it's wintertime in NH, temps were just above freezing), flushed the toilets, opened the fridge/freezer doors, connected to the internet (router), and used the lights intermittently. After three hours the DP3 had used ~15% of it's available power (90% to 75%). I then connected the Hyundai Ioniq 5 V2L adapter and plugging in the DP3. The DP3 ran the house loads and recharged to 90% in less than 30 minutes.

The DP3 has a 4 kWh battery. With an average of about 15% for 3 hours, the DP3 would last about 18 hours by itself (using 90% of the total capacity). Another way of looking at it - my house used about 0.2 kW per hour. My 2024 Hyundai Ioniq 5 has a battery capacity of 74 kWh (usable). Even if I only use 50% of that (37 kWh) for backup power, my HI5 can provide about 185 hours (>7 days) of backup power for my house.

For reference (source):

• the Scout Harvester will have a 60-70 kWh battery
• the Scout BEV will have a 120-130 kWh battery

Thanks for your use case information. Something to think about.

 

[Logan]

There have been several discussions in the Scout forums about using the Scouts as backup power during a power outage. I wanted to share some of my information so people have some real data to use if they are planning for this. Note that the data is specific for my house - but you should be able to extrapolate for your own situation.

I have a transfer switch installed on my house so I can safely power my critical circuits during a power outage. The following are attached to those circuits:

• well pump (240V 30amp circuit)
• heat and hot water (propane tank-less system, so just a 15amp circuit for the electronics)
• kitchen refrigerator/freezer
• basement upright freezer
• cable router
• miscellaneous lights

I have a Delta Pro 3 to use as my primary backup power supply. I selected this unit because it has a 240V output I can plug into the transfer switch; the DP3 will provide split phase 240V power for my well pump. The DP3 also allows me to plug in a 120V source to recharge the battery while it is providing 240V output, so I can recharge the DP3 while still providing power to the house via the transfer switch. During an extended outage I can use the V2L adapter I have for my Hyundai Ioniq 5 to recharge the DP3 when necessary.

I tested all this a few days ago. I connected the DP3 to the transfer switch and switched over to using it for power. I ran the the DP3 for 3 hours. During that time I ran a hot shower for 10 minutes, ran the heat (it's wintertime in NH, temps were just above freezing), flushed the toilets, opened the fridge/freezer doors, connected to the internet (router), and used the lights intermittently. After three hours the DP3 had used ~15% of it's available power (90% to 75%). I then connected the Hyundai Ioniq 5 V2L adapter and plugging in the DP3. The DP3 ran the house loads and recharged to 90% in less than 30 minutes.

The DP3 has a 4 kWh battery. With an average of about 15% for 3 hours, the DP3 would last about 18 hours by itself (using 90% of the total capacity). Another way of looking at it - my house used about 0.2 kW per hour. My 2024 Hyundai Ioniq 5 has a battery capacity of 74 kWh (usable). Even if I only use 50% of that (37 kWh) for backup power, my HI5 can provide about 185 hours (>7 days) of backup power for my house.

For reference (source):

• the Scout Harvester will have a 60-70 kWh battery
• the Scout BEV will have a 120-130 kWh battery

This is great.

I have a similar setup at home, but currently missing the 240v output side of things. I currently have an Ioniq 9, which can also use the V2L adapter to access its 107kwh useable battery. The problem is its low output (120v x 15amps :/). I also have a manual transfer switch.

I was considering adding a battery/inverter to provide more power when needed like you did, but considering I also already have a 240v generator, and most 240v output capable power stations/inverters cost more than the generator... I haven't done anything yet. Especially considering that the Scout will likely make the Ioniq 9's role in this process obsolete, in just a year or two.

Our usage is different. Almost everything in our home is electric (save the propane stovetop, and fireplace). We have a heat pump water heater, and a heat pump heater (with backup resistive electrical heating). We have a freezer in the garage, a fridge/freezer in the kitchen inside, networking gear, and then the fireplace blower.

We had a power outage this year that was relatively short (2-3hrs), and I got to test things a bit. I did the above load + my gaming computer (which seems to use a few hundred watts, I forget the exact number). And everything worked fine... until I think one of the fridge/freezers did a defrost cycle. Because after about an hour and a half of < 1kw of output, the breaker on the end of the V2L adapter tripped.

I also noticed that the V2L adapter doesn't like the surge load of having all of the circuits at the same time. So I have to be careful to engage the 120v circuits one by one now (whereas my generator doesn't care if I just flip them all on at once, despite being a ~3250w 120v generator).

But in that ~2hr or so window, we used 1% of my Ioniqs battery. But, the V2L adapter efficiency is unknown. IIRC, I was seeing estimates of ~70hrs or so, with a ~400w-1000w load on it (I have a screenshot showing 66hrs left with 400w load, and 81% battery).

Oh, and one other thing. For the V2L adapter situation, you don't get to use all of the battery. It always keeps some in reserve (I think 20% is the default??). So in my 66hr situation, I was actually only using ~61% of the battery, because it would only draw down from where I was at the time (81%) to 20%.

 

[J Alynn]

There have been several discussions in the Scout forums about using the Scouts as backup power during a power outage. I wanted to share some of my information so people have some real data to use if they are planning for this. Note that the data is specific for my house - but you should be able to extrapolate for your own situation.

I have a transfer switch installed on my house so I can safely power my critical circuits during a power outage. The following are attached to those circuits:

• well pump (240V 30amp circuit)
• heat and hot water (propane tank-less system, so just a 15amp circuit for the electronics)
• kitchen refrigerator/freezer
• basement upright freezer
• cable router
• miscellaneous lights

I have a Delta Pro 3 to use as my primary backup power supply. I selected this unit because it has a 240V output I can plug into the transfer switch; the DP3 will provide split phase 240V power for my well pump. The DP3 also allows me to plug in a 120V source to recharge the battery while it is providing 240V output, so I can recharge the DP3 while still providing power to the house via the transfer switch. During an extended outage I can use the V2L adapter I have for my Hyundai Ioniq 5 to recharge the DP3 when necessary.

I tested all this a few days ago. I connected the DP3 to the transfer switch and switched over to using it for power. I ran the the DP3 for 3 hours. During that time I ran a hot shower for 10 minutes, ran the heat (it's wintertime in NH, temps were just above freezing), flushed the toilets, opened the fridge/freezer doors, connected to the internet (router), and used the lights intermittently. After three hours the DP3 had used ~15% of it's available power (90% to 75%). I then connected the Hyundai Ioniq 5 V2L adapter and plugging in the DP3. The DP3 ran the house loads and recharged to 90% in less than 30 minutes.

The DP3 has a 4 kWh battery. With an average of about 15% for 3 hours, the DP3 would last about 18 hours by itself (using 90% of the total capacity). Another way of looking at it - my house used about 0.2 kW per hour. My 2024 Hyundai Ioniq 5 has a battery capacity of 74 kWh (usable). Even if I only use 50% of that (37 kWh) for backup power, my HI5 can provide about 185 hours (>7 days) of backup power for my house.

For reference (source):

• the Scout Harvester will have a 60-70 kWh battery
• the Scout BEV will have a 120-130 kWh battery

I appreciate your post and others just getting the info out to all of us

 

[J Alynn]

This is great.

I have a similar setup at home, but currently missing the 240v output side of things. I currently have an Ioniq 9, which can also use the V2L adapter to access its 107kwh useable battery. The problem is its low output (120v x 15amps :/). I also have a manual transfer switch.

I was considering adding a battery/inverter to provide more power when needed like you did, but considering I also already have a 240v generator, and most 240v output capable power stations/inverters cost more than the generator... I haven't done anything yet. Especially considering that the Scout will likely make the Ioniq 9's role in this process obsolete, in just a year or two.

Our usage is different. Almost everything in our home is electric (save the propane stovetop, and fireplace). We have a heat pump water heater, and a heat pump heater (with backup resistive electrical heating). We have a freezer in the garage, a fridge/freezer in the kitchen inside, networking gear, and then the fireplace blower.

We had a power outage this year that was relatively short (2-3hrs), and I got to test things a bit. I did the above load + my gaming computer (which seems to use a few hundred watts, I forget the exact number). And everything worked fine... until I think one of the fridge/freezers did a defrost cycle. Because after about an hour and a half of < 1kw of output, the breaker on the end of the V2L adapter tripped.

I also noticed that the V2L adapter doesn't like the surge load of having all of the circuits at the same time. So I have to be careful to engage the 120v circuits one by one now (whereas my generator doesn't care if I just flip them all on at once, despite being a ~3250w 120v generator).

But in that ~2hr or so window, we used 1% of my Ioniqs battery. But, the V2L adapter efficiency is unknown. IIRC, I was seeing estimates of ~70hrs or so, with a ~400w-1000w load on it (I have a screenshot showing 66hrs left with 400w load, and 81% battery).

Oh, and one other thing. For the V2L adapter situation, you don't get to use all of the battery. It always keeps some in reserve (I think 20% is the default??). So in my 66hr situation, I was actually only using ~61% of the battery, because it would only draw down from where I was at the time (81%) to 20%.

View attachment 12825

Thanks to you as well for your insight

 

[N Wilson]

Pretty sure I shared this in another thread.

The F150 Lightning I bought a few months ago has a 240V outlet and V2L capability so I had my electrician install a manual transfer switch and generator inlet plug on my house. I already had my critical loads circuits in a subpanel, so the electrician just wired the transfer switch so that the subpanel would be powered by the generator inlet feed.

My setup is similar to @BeerParty except I just plug the 240V from the truck directly into the generator inlet plug on the house. No separate battery system involved. If I didn't have the 240V outlet on the truck, I probably would have gotten a battery system like the Eco Flow or similar.

The truck can provide 7.2 kW of power, so I can't back up high-draw loads like the electric water heater, electric stove, and wall oven but I can back up almost everything else including all the lighting circuits for the living areas, kids bedrooms, well pump, fridge, router, etc.

In the event that I have an extended power outage where the truck battery gets depleted down to my set reserve limit (unlikely since it holds about 9.7 Powerwalls worth of energy) I can drive to a DCFC about 20 minutes away and recharge.

 

[dreamweaver]

Pretty sure I shared this in another thread.

The F150 Lightning I bought a few months ago has a 240V outlet and V2L capability so I had my electrician install a manual transfer switch and generator inlet plug on my house. I already had my critical loads circuits in a subpanel, so the electrician just wired the transfer switch so that the subpanel would be powered by the generator inlet feed.

My setup is similar to @BeerParty except I just plug the 240V from the truck directly into the generator inlet plug on the house. No separate battery system involved. If I didn't have the 240V outlet on the truck, I probably would have gotten a battery system like the Eco Flo or similar.

The truck can provide 7.2 kW of power, so I can't back up high-draw loads like the electric water heater, electric stove, and wall oven but I can back up almost everything else including all the lighting circuits for the living areas, kids bedrooms, well pump, fridge, router, etc.

Repeat or not still good information. Thanks for sharing your experiences.

 

[chucchinchilla]

As you guys know this very much piques my interest as the power company here in Northern California, PG&E, sucks and outages happen way more often than they should. I'd be interested to know everyone's opinions on V2H enabled home chargers. Ford makes one, GM makes one, but those are both for exclusive use on their own vehicles. Anyone know of any good ones out there? Maybe it's still a limited market and we just have to wait a couple years for more to come out?

 

[Logan]

As you guys know this very much piques my interest as the power company here in Northern California, PG&E, sucks and outages happen way more often than they should. I'd be interested to know everyone's opinions on V2H enabled home chargers. Ford makes one, GM makes one, but those are both for exclusive use on their own vehicles. Anyone know of any good ones out there? Maybe it's still a limited market and we just have to wait a couple years for more to come out?

Right now, they're all suuuuper expensive. IIRC the Ford one was required to be installed by some third party, and was somewhere on the order of $4-5k to buy/install.

More are coming, but TBH, the whole thing feels very "early days". I personally plan to wait a while, especially since I already have a 240v L2 charger at home that works just fine.

The cheap/cheerful way to do it is just like @N Wilson did. A manual transfer switch, with a NEMA 14-50, or 14-30 plug. Then you just pull out a cable, and connect your EV to the cable, and boom, you're done. This is especially cheap if you already have the transfer switch.

In my case, my home came with a manual transfer switch (NEMA 14-30), but my vehicle can only output 120v x 15amp, and so I had to get an adapter to go from a NEMA 5-15 to NEMA 14-30 to make it all work.

Given, it would be nice to have everything automatically fail over. But even though we have had 5-10 power outages a season, its not "that" much of an inconvenience to just to move things over manually. Especially considering what we've been doing previously (hauling out the generator, fueling, etc).

In my setup, being limited to 120v x 15amps is sort of annoying. But, its plenty for the "normal" stuff. Importantly, I can run the house completely silently while we're sleeping (I never sleep well with the generator going outside constantly), AND this is something my wife can easily do if I was gone (no more pulling out the 90lb generator + propane tanks).

And if its a long outage, we can use the ioniq overnight, and then use the generator during the day to power higher power loads (microwave, space heaters, whatever).

But I do look forward to 240v output for this scenario. I really hope that the Scout comes with at least 240v x 30 amp output. Although a 50amp output would be even better (still not enough to run everything in my house like the backup resistive heating, but enough for the heat pump).

 

[MountainDad]

V2X is interesting as an idea only if you have some other vehicle to get you out of Dodge when an evac order comes in. Those of us in the West have to plan for fires, floods, etc - of your power goes out, it's usually because there's a natural disaster somewhere nearby. So, I would much rather have a home generator with battery backup system. I already have a 7.3kW peak solar power system, so adding a battery backup with a generator is a relatively small (and decreasing) expense. There are now solutions that can power HVAC, lights, and essential appliances for around $10k.

 

[MountainDad]

As you guys know this very much piques my interest as the power company here in Northern California, PG&E, sucks and outages happen way more often than they should. I'd be interested to know everyone's opinions on V2H enabled home chargers. Ford makes one, GM makes one, but those are both for exclusive use on their own vehicles. Anyone know of any good ones out there? Maybe it's still a limited market and we just have to wait a couple years for more to come out?

Our Genesis GV60 with 75kwH battery is V2L capable

 

[BeerParty]

V2X is interesting as an idea only if you have some other vehicle to get you out of Dodge when an evac order comes in. Those of us in the West have to plan for fires, floods, etc - of your power goes out, it's usually because there's a natural disaster somewhere nearby. So, I would much rather have a home generator with battery backup system. I already have a 7.3kW peak solar power system, so adding a battery backup with a generator is a relatively small (and decreasing) expense. There are now solutions that can power HVAC, lights, and essential appliances for around $10k.

Our Genesis GV60 with 75kwH battery is V2L capable

If you are adding batteries to your solar system and have a EV with V2L, you can skip the generator. The batteries would work just like my Delta Pro 3 does, and you can use the V2L to charge up the batteries when they get low.

 

[BeerParty]

As you guys know this very much piques my interest as the power company here in Northern California, PG&E, sucks and outages happen way more often than they should. I'd be interested to know everyone's opinions on V2H enabled home chargers. Ford makes one, GM makes one, but those are both for exclusive use on their own vehicles. Anyone know of any good ones out there? Maybe it's still a limited market and we just have to wait a couple years for more to come out?

In my opinion, for your situation where you often get power outages, I would not suggest a V2H solution. There are many disadvantages to a V2H solution, the main three being:

• high cost and they require professional installation
• limited availability and most are proprietary solutions
• the vehicle has to be connected to the charger to have backup power

A power station with a transfer switch like I have will provide plenty of power to the critical loads in my house. It costs much less than any of the V2H solutions and doesn't tie up my vehicle to provide backup power. But it still benefits from a BEV with V2L, since I can recharge the power station without needed a separate generator.

 

[chucchinchilla]

In my opinion, for your situation where you often get power outages, I would not suggest a V2H solution. There are many disadvantages to a V2H solution, the main three being:

• high cost and they require professional installation
• limited availability and most are proprietary solutions
• the vehicle has to be connected to the charger to have backup power

A power station with a transfer switch like I have will provide plenty of power to the critical loads in my house. It costs much less than any of the V2H solutions and doesn't tie up my vehicle to provide backup power. But it still benefits from a BEV with V2L, since I can recharge the power station without needed a separate generator.

So when I wired my home to charge our EV, I simply had a 240V outlet installed next to our driveway. We then plug an L2 charger into that and use it, with the idea being over time that L2 charger will change but the outlet/wiring will remain. So in order to enable home backup, could I have that 240V outlet first connect into a manual transfer switch that then plugs into the main electrical panel? From there it would simply be a case of either plugging my Anker power station into the 240V outlet or some future bidirectional EV charger, is that right?

 

[rodhx]

So when I wired my home to charge our EV, I simply had a 240V outlet installed next to our driveway. We then plug an L2 charger into that and use it, with the idea being over time that L2 charger will change but the outlet/wiring will remain. So in order to enable home backup, could I have that 240V outlet first connect into a manual transfer switch that then plugs into the main electrical panel? From there it would simply be a case of either plugging my Anker power station into the 240V outlet or some future bidirectional EV charger, is that right?

I have the same setup, a 14-50 outlet mounted between the garage doors for my charger. During extended power outages I use that circuit as you describe with my gas generator. If my Rivians could put out 220V I could use them instead of the generator.