Electric cars for backup power
Posted by www_nsfw@reddit | preppers | View on Reddit | 68 comments
I've heard a few recent stories from the hurricanes where fully charged electric cars provided 1-2 weeks of backup power for basics like refrigerators, phone chargers, stoves, etc. Admittedly they are very expensive, but have you considered an electric car as part of your prepping arsenal?
SgtPrepper@reddit
Actually you can use a regular car as a generator. All you need is an inverter and then you're set to power a couple of appliances at least.
davidm2232@reddit
That is one of the least efficient ways to do it though. You burn through a lot of fuel and it's not great for cars to idle for extended periods
ZCaptainR@reddit
you can idle a gas powered car forever with no problem, a diesel is a different story.
davidm2232@reddit
At least with small non emissions diesels, wet stacking really isn't an issue at idle.
SgtPrepper@reddit
An idling car uses very little gas. The tricky bit is making sure the carbon monoxide from the exhaust is routed somewhere harmless (maybe a hose out to the street).
I'm not sure about extended idling periods being bad for the car however. During the Pandemic I was sure to run mine every once and a while and it turned out okay.
davidm2232@reddit
A typical 4 cylinder gas car engine is going to burn .5 gph.
851Moto@reddit
Do i understand this right... an inverter hooked to a 12v battery, then you idle the car occasionally to keep it charged?
SgtPrepper@reddit
From what I've read, the best way to go is to find an inverter that matches the wattage of the inverter. The tricky bit would be to know how low the battery is running. A car idling however doesn't use that much gas.
An even better possibilities, modern cars are (often annoyingly) programmed to turn off their engine if they're stopped at a traffic light. As long as that includes turning on the engine to charge a low battery, you'd be golden.
thepete404@reddit
Inverters can flatten a car battery pretty quickly depending on size. You’ll have to do a little more then idle . You should know the size of your alternator also typically 65 amp at 12v is the minimum. Better off burning fuel in a cheap 2kw generator
Big-Preference-2331@reddit
Ya I think this is the most economical way for back up power. I bought a 1000w inverter at a pawnshop for 40 dollars.
Dangerous-Kick8941@reddit
If I were to get a vehicle for power generation, I'd be looking at the F150 Powerboost hybrids with the 7.2kw split phase inverter in the bed.
sviper9@reddit
I'm in Texas, but I have a '21 Powerboost with the 7.2kW setup (30A @ 240V). I have a generator hookup for my house and already tested this. It works well and runs my 2 fridges, chest freezer, upright freezer, lights, and outlets. Runs everything except for my 5-ton A/C unit. I could probably get a soft-start for it and run it too, but that's lower on my todo prep list.
I haven't recorded fuel consumption, but some info online says if you run the 7.2kW full out, you can get 36-ish hours of runtime with a full tank of gas. My needs aren't even half of that in a power outage situation, so I would be good for a long time.
Dangerous-Kick8941@reddit
How's it for daily driving and all?
sviper9@reddit
Really great daily driver. I describe the drive feel like a sedan. Lots of storage. I don't have the tow package, so the suspension is softer, which is what I wanted. It can get a little tight in small parking spaces (especially garages in downtown Austin), but I'm able to manage.
I have the Lariat trim with 20" wheels. I also have a lead foot, which doesn't help range. I record all of my fill-ups, and since I got the truck in August 2021 until now I get an average of 22.57 mpg. EPA rating is 24/24/24. Average distance between fill-ups is 565.3 miles.
I've done many things with it and it works great. Camping, beaches, minor rock crawling, towing distances of 500+ miles, and more. Impressed one of my buddies by running his 1500W coffee maker out of the back during a camping trip.
Just recently I got a car refrigerator + 500Wh battery to keep things cool in the truck. I've only done drinks so far and it works well. The generator mode prompt comes on when something is detected as plugged in and charges the battery. Then I run the fridge off of the battery while parked. I haven't tested it in 100+ degree weather yet, but good so far. I have it under a tonneau cover.
I keep a ton of stuff in the truck, which I outlined here: https://www.reddit.com/r/F150Lightning/comments/1dzgrem/what_are_some_musthave_accessories_for_this_truck/lcg9nxg/
Dangerous-Kick8941@reddit
Thank you for all the good info.
WishIWasThatClever@reddit
As someone with saltwater storm surge from Helene inches outside my front door, that’s a giant fireball of a nope for me. Way way too high of a risk of fire when EVs are exposed to salt water.
davidm2232@reddit
A car lift would fix that issue for less money than a good generator
douche_packer@reddit
Did that happen in either of these big hurricanes over the past month?
WishIWasThatClever@reddit
https://www.wusf.org/weather/2024-10-11/after-hurricane-milton-growing-risk-flooded-electric-cars-going-up-flames
LastEntertainment684@reddit
Keep in mind Florida has over 250,000 registered EVs with an estimated 50,000 were in the path of Milton. Depending on which article you read, the number of affected vehicles was somewhere around a dozen.
Modern EVs are getting much better here with sealed battery cases and newer battery technologies that are not susceptible to thermal runaway.
Presently the most dangerous vehicles for fire risk are actually hybrids.
Sea-Independence-775@reddit
A couple houses burned down because of it
douche_packer@reddit
link? (im actually interested)
WishIWasThatClever@reddit
https://www.wusf.org/weather/2024-10-11/after-hurricane-milton-growing-risk-flooded-electric-cars-going-up-flames
floridabrass@reddit
Yeah it did happen in Tampa.
LastEntertainment684@reddit
Yup, I’ve got a mix of gas and diesel vehicles as well as a Ford Lightning EV.
Not all EVs have what’s called V2L or Vehicle2Load capability, but the ones that do have varying levels of output so you have to understand what you’re getting as far as output and run time. In the case of my Lightning I have a 30amp 240v output that I use in conjunction with a transfer switch to power select circuits in my home. I can run my home about a week.
There’s a few notable things that are great about it:
It’s completely silent vs a combustion engine so it doesn’t attract attention.
There’s no fumes, so it can be run from inside a garage.
I can recharge the battery using multiple power sources (solar, wind, dual fuel gasoline and propane generator, diesel generator, etc) or at a public DC fast charger
A gas station may only have enough gas on hand to service a few hundred cars and are often quickly depleted. DC fast chargers can service a potentially limitless amount as long as they have power. Many are both grid connected and have their own backup generators.
DC fast chargers talk to charging apps, so if you have cellular or WiFi connection you can see which chargers are up likely up and running. No driving around wasting gas looking for a working gas station.
The downside is it is basically a big power bank, so you still need to figure out a method to recharge it. If you’re completely isolated you’re probably looking at a generator as your least expensive option.
However, it can be a fairly efficient way to operate as you can size the generator to operate in its most efficient power-band when it’s charging. It doesn’t have to throttle up and down as load changes, or worse, run at full throttle for a minimum load.
I can recharge my truck off my generator in just hours and then have another week worth of power.
The majority of reports from EV owners during Helene and Milton have been overwhelmingly positive. There was even a Rivian truck that floated downriver and the owner was able to hop in, start it up, and drive away.
tvtb@reddit
I have one of the EVs that nominally has no V2L support but I make it work anyway.
I got a Chevy Bolt and a 1000W (2000W peak) inverter wired up. Cost about $400 including bits and bobs. I can pass a power cord through a window and power fridges, hot plates, internet gear, whatever I want for many days.
Jodokkdo@reddit
Really want to know how to do this with our little BMWi3. Can you explain the hook-up?
tvtb@reddit
Honestly, it requires you go over to r/BMWi3 and get help. There is lots of model-specific things you have to know, and people who have tried it before will know what works and what the limits are.
These inverters hook into the 12VDC system. For the Bolt, people figured out that the "alternator" that charges the 12V battery from the 400V battery can't keep up if you use a 1500W or larger inverter maxed out, so you should stick to a 1000W inverter. You'll need to figure out what the limit is for your BMW.
Jodokkdo@reddit
I have a Lightning and live just above Asheville. Powered four neighbors' fridges and much of our house for three days.
spudmuffinpuffin@reddit
What generator and size battery? That's an incredibly efficient use of gas
LastEntertainment684@reddit
Truck has a 131kw usable battery capacity, I’ve set it to shut off at 50 miles remaining. Ends up being about 100kw or so.
I can handle up to 80amps @ 240v charging, but for portable generators you’ll typically be limited to 30-40amps. So you’re about half a day worth of charging for 100kw.
Between running my lights, fridge/freezer, router/modem, tv, charging devices, and occasionally running a well pump I average less than 1,000watts/hr. So theoretically about 4 straight days but I’ve stretched it out longer.
junk986@reddit
Basic models start at 25k that will do it.
Teslas have been able to do it since they bought solar city. That tech was ingested and the cars do it now but not the way you’d think. Pre-cybertruck, you would use a SolarCity inverter and connect it directly to the battery in the dog-house under the rear seat. That place also has 12v access that wouldn’t be regulated by a fuse box. You get 6-12kw of power. People turned their Model X into sleeper vans and lived “off-grid”, occasionally coming into town to supercharge for free (Tesla has a free program initially with a lifetime warranty on drivetrain including batteries). You can still find these old Xs but you have to be very careful on how you transfer ownership, working with the seller to move everything over. Teslas since then have been all able to do this. The Cybertruck has a 50A outlet which pushes out a full 12kw of power. This allows you to run electric heat, if you have it.
So out the door, the cybertruck takes care of everything if you have an inlet. It will energize the full inlet too.
F150 is basic at only about 6kw output on its 50A (how is that legal ?), but should be enough to energize some things. F150 ICE also has this feature but not sure how long it would run.
The F150 Lightning needs external help to go above the 6kw cap with a very expensive equipment from a solar supply company (kinda like Teslas old trick pre-cybertruck).
Pretty much any other car will output 1500-1800w on an inverter. EVs will just do it longer. If you have a furnace…it will run a furnace and fridge for a long time. No need to buy and deal with Hyundai, as again…their V2L in the USA is 1800w. Their European offerings have 240V output…which is something…but that’s not what is sold in the USA. The inverter is onboard and a separate board at that.
jaOfwiw@reddit
I've a cybertruck reservation I'm floundering on. It's 123 kwh pack. All I need to do is run a conduit and cord to my garage and I can back feed a smart panel from the truck. I could build a 123kwh pack for much cheaper, maybe 30-50k.. but I couldn't drive it and haul shit with it as well.
silasmoeckel@reddit
Pure EV nope.
Onboard generator EV yup anxiously awaiting one to ship next year.
Not sure on expensive a chevy bolt is like 27k.
Dangerous-Kick8941@reddit
The F150 Powerboost has an onboard 7.2kw inverter option for the hybrids.
silasmoeckel@reddit
That hybrid powertrain wont let me legally use farm/av gas where I live and as an EE I realy like an all electric drivetrain. The pure electric range would fit the vast majority of the driving and ethanol free fuel keeps far better.
Dangerous-Kick8941@reddit
What's farm gas? Ethanol free? I don't see how the onboard computer would care, other than under boost conditions. I can understand the ecu being upset about leaded aviation gas.
silasmoeckel@reddit
ECU doesn't care the issue is shelf life ethanol makes that problematic.
Unleaded avgas is a thing now.
Dangerous-Kick8941@reddit
Ah, so mainly a taxes and storage issue.
I've not had problems storing e10, but then I burn it in low compression, carbureted stuff for the most part.
silasmoeckel@reddit
E10 Gives me trouble unless I completely drain carbs.
A friend had a volt similar concept they had to put in a function to use the gas after a year the fuel system would get clogs with all the junk from the e10. Stabil and similar helped.
The ram has a much longer battery only range so expect a tank to last a lot longer.
fluteofski-@reddit
Tbh tho. A bolt is a fantastic little car. I picked one up used for $13k with 20k miles and a new traction battery that was replaced under recall. I’ve been looking at the inverter setup for this thing.
A fully charged Chevy bolt will run my fridge, WiFi, and laptops for like 2 weeks.
BigMain2370@reddit
I'm on the waiting list for the Ramcharger. Not sure I'll commit to the first model year, though.
92kwh battery and a built-in 130kw generator, with like ~30 gallon gas tank.
I would definitely opt for the 7.2kw "power panel," which isn't near my current home backup, but would realistically be more than I need in an emergency.
silasmoeckel@reddit
I'm also thinking wait 2-3 years for things to shake out and pick up an off lease one.
Ok-House-6848@reddit
It me a good idea, but you are taking the risk of having a severe fire hazard if flooding is extreme and the salt water makes the battery catch on fire.
efnord@reddit
Tesla Powerwall 3 is $6500 for 13.5kwh- that's with the 30% federal tax credit. Compare the prices and remaining battery capacity for first-generation Nissan Leafs, or Chevy Bolts.
rockycore@reddit
You can get a used bolt in my area around 15k with the point of sale credit. That's 65kwh. Yeah, maybe a little degradation gets you down to 60kwh (highly doubt it would be this low). Granted with an inverter, you can only pull 1200 watts.
Also $6500 isn't including actually installing the powerwall and any upgrades your electrical system might need.
So yeah it's not clear cut.
fastowl76@reddit
I believe the Leaf has been designed for 2 way power flow for a long time. In Japan, I have read that various government entities have a plan where they bring in multiple Leafs to provide emergency power at a select location.
efnord@reddit
Yah- cheap mobile power, but getting more than 1500W out at once generally isn't cost-effective. Comparable to a suitcase inverter generator, in my head.
patssle@reddit
Can get 15kw of server rack battery (Eg4) for $4k before tax credit. Even without a solar array, it can power a full fridge/freezer for 5 days (depending on the fridge of course).
BigMain2370@reddit
That's a big point for cars over powerwall. That's why I keep considering the Ramcharger coming out next year. Not nearly as big of a battery as the 229kwh Rev, but it includes a built in generator with a ~30 gallon gas tank.
BaldyCarrotTop@reddit
Not really. It's a car (or truck) first and I would have to be able to justify the expense based on that. V2L would be a secondary consideration.
For a lot less than an EV I can buy a couple of server rack batteries and a hybrid string inverter. I'll be going that route first.
rctid_taco@reddit
I already have an EV (plus a PHEV) but using them for backup power is of little interest to me. I have a small generator and a couple tanks of propane for that along with a "solar generator" and solar panel for powering smaller loads. If the propane runs out then I want the EV fully charged so I can hopefully go out and buy more fuel. If that's still not possible then it's probably time to leave town for a bit.
Jammer521@reddit
I never buy new cars I'm to cheap and I don't want a car payment, I'm driving a 2008 ford escape that has been paid off for 12 years, I still spend about 1k a year maintain it, but still cheaper than a car payment
TheSensiblePrepper@reddit
I have a Tesla Model S that I can use like that. I also have solar panels and a battery bank in my house. My Tesla would be the last thing I pulled power from but I could certainly do it. I have tested it and had no issues.
I wouldn't buy an electric car for that reason but it is a great bonus.
Big-Preference-2331@reddit
My daughter has an older Model S. Does it have an outlet somewhere?
TheSensiblePrepper@reddit
It does but it reverses power flow via the charging port.
Big-Preference-2331@reddit
Oh wow. Do you need a special charger for it? I’ve seen people in New Zealand power their homes with a Mitsubishi outlander PHEV but they have special chargers.
TheSensiblePrepper@reddit
You do if you want quick charging and some other features.
Big-Preference-2331@reddit
I have two Teslas and a Mitsubishi PHEV Outlander. None of them are good power sources(without voiding the warranty). I don’t think the Teslas are built for it yet and the Outlander requires an expensive charger that allows vehicle to grid. If SHTF I’m running an inverter off my old F-250 and using my EVs for transportation.
I could live in my Model Y and put it in camp mode for short term events.
Fun-Brilliant2909@reddit
Yes, like the Ford Lightning (not the Ford SVT Lightning) has crossed my mind. I've watched videos of people operating their pumps and other equipment with their electric vehicles. I think a cheaper alternative would be an actual generator. However, an electric vehicle would make an exceptional asset in addition to other electricity-providing devices like batteries/powerbanks and generators (solar, wind, hydro, thermal, gasoline/diesel engine). The downside is that electric vehicles are expensive devices prone to failure in the presence of water/flooding.
spudmuffinpuffin@reddit
Affordable home builder here. Schneider electric makes a ton of parts for all segments of the electrical grid: stuff at power plants down to the breakers at home. Part of the evolution of the power grid is solar panels and electric cars at homes becoming part of the overall production and storage within a region. We're already building net zero homes efficient enough to last a few weeks on solar panels, home batteries, and an electric car battery. I'm excited to upgrade my own home one day.
I have a friend in Tampa without power who is charging his car at work to power his home at night. He rarely fires up his inverter generator.
xmodemlol@reddit
Any car is a backup generator…there’s 110v cigarette lighters converters that go up to 500w.
Of course an electric with v2l would be amazing, but there’s only a few ev cars that can do it, and most houses aren’t wired for it.
rankhornjp@reddit
I've used my electric golf cart for backup power. It cut down on my generator usage. I would use the generator during high load time (evening cooking, bathing, and also charging the golf cart). Then, when I turned off the generator, I would connect all the loads to an inverter connected to the golf cart battery.
Trail_Breaker@reddit
It's a nice idea, but how long will the battery last? Especially if it's cold. My aunt and uncle were able to use their diesel pickup to generate power for their RV back in 2021 when Texas had a big power outage in the middle of winter.
juggarjew@reddit
I can use 61.6kW of my EV6's 77kW battery pack, so it all depends on what items you want to run. It was a great help during Helene at night when we didnt want to run a generator at bed time.
juggarjew@reddit
I have a 2022 Kia EV6, during Helene we used it as our bedtime power source, we didnt want to run a generator all night as it was very wasteful plus it could be stolen. So I used the V2L feature of my car (one of the reasons I bought it honestly) that allows access to 80% of the cars battery power. The battery is 77kW so 80% of that is 61.6kW. Thats a hell of a battery back and makes my 2kW Ecoflow look like nothing. Its provides a single 1900 watt 120 volt outlet, very useful for fridge, TV, internet, fans, etc.
Perfect solution for times when you dont want to run the generator. makes a powerwall look weak lol
incruente@reddit
I have not. It's impractical for me as a means of transportation, particularly given what they cost. And as a standalone means of energy storage, they're inferior to just getting a purpose-made rechargeable battery.
HorseBarkRB@reddit
Curious to see the answers. We have a Prius and went down that road a while back. I think the answer was 'no' but I can't recall specifically why. I did read a post recently about using a car battery and that being a bad idea. That answer had to do with the batteries not being designed to be fully discharged. Once fully discharged, the batteries will not recharge to capacity again.
The other thought is for a hurricane, I'm not sure where you would put a car that would be safe unless your only concern is wind? There were people who prepped for Milton by driving their cars inland and then hunkering down in their homes that were nearer the water.