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Prius as Generator When Power Is Out

Discussion in 'Gen 3 Prius Main Forum' started by ca3799, Jul 18, 2024 at 12:49 AM.

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  1. ca3799

    ca3799 Junior Member

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    I'm in post-hurricane Houston and am interested in using one or more of my 3 (yes, 3) Priuses as an emergency generator for the next freezepocalypse or baby hurricane that comes my way. I like that I already own 3 potential generators in my driveway so would not have to spend several hundred dollars or more on a gas- or solar-powered generator. I also really like that the car is quieter than a generator, the exhaust is less, cleaner, and will be further away from the house. It seems reasonable that the car must be much more fuel efficient than a gas generator since gas will only be used intermittently to power up the HV battery. The only downside I can see is that I can't get as much power from the car as I can from a traditional generator (more on that below) but that's fine with me.

    Reading fellow Houstonians post-hurricane comments, I can see that folks spent a lot on gas (gasoline and LP gas) and also used a lot of gasoline/LP gas which was hard to find for a few days, defeating the purpose of having a stand-alone generator. I don't have the option of a an installed gas line.

    According to very many post-storm reports, gas generators seem to use about one-half to one full gallon of gas per hour and also require frequent maintenance and rest periods that I'm not terribly interested in doing. I don't know what a Prius would use in gasoline just sitting in "Ready" state, but it certainly would be less than what a gasoline-powered generator would use.

    I've gathered from reviewing possibly every post or video available in the internet that I should not use a larger than 1000 watt (pure sine wave if using for any delicate electronics) inverter on the 12v battery to stay comfortably below maxing out the potential wattage available via the car.** I have seen 2 YT videos and one comment on here from folks who have used a 2000 watt inverter, but I think they overbought and I'd also like to stay low to not put any of my 3 cars in any danger since all 3 are also daily use vehicles.

    So is the 1000 watt inverter the best choice for safety in your (anyone who has considered, is knowledgeable about, or has done this) opinion? I think so. Do you see any flaws in my reasoning here?

    I also understand I should stay 20% below the maximum of 1000 watts available using the inverter so I was thinking that I could get a comfortable 800 watts per car. 800 watts would give me a great deal of comfort. I've determined that my fridge uses 379 watts. Caution says I should allow twice that for surges- or when the fridge needs to power up- so I calculated to allow the fridge 758 watts max. I'm thinking I would use one car and one 1000 watt inverter as a stand-alone for the fridge only. Spending about $200 dollars on an inverter, connecting cables, and a heavy duty power cord, and not losing a couple of hundred dollars worth of food makes this seem like a good investment. Do you (anyone who has considered, is knowledgeable about, or has done this) have an opinion on this? Any reason why the cables from the 12v battery/ground to the inverter should be heavy duty cables?

    I was thinking I could disconnect the fridge from time-to-time to power other kitchen stuff except that other kitchen items use a surprisingly large amount of power. For example, the coffee pot says it needs 1550 watts. The microwave says it needs 1150 watts. The tea kettle wants 1000 watts. At these numbers, I'm not sure I can actually use even the tera kettle if I adhere to my previous cautious plans of 800 watts max. I guess I'm wondering if I'm being overly cautious or if I should just plan on some other method(s) of food prep.

    I still have two other cars and could use one or two of them to run stuff like fans, lights, and even the router and household computers, since none of those items are watt-hogs. This would make life much less boring.

    A final question- most inverters allow for two extension cords. I presume this means, using my cautious math, that I can only plan on about 400 watts per cord (or 500/300, 0r 200,600, etc.) Is this correct?

    I guess I'd like opinions and thoughts on these plans and also opinions and thoughts on if I'm being too conservative on my planned usage of 800 watts per car.



    **"The Prius (all generations, as far as I'm aware) has a 100 amp (fuse limitation) on the DC to DC converter that charges the 12V battery.

    100 amps x 12 volts = 1200 watts absolute maximum.

    The car's electronics require some portion of that maximum 1200 available watts while in READY mode.

    A 1000 watt continuous inverter is the absolute largest one recommended, if drawing power through the 12V battery."
    Credit to SweetBearCub here:
     
    #1 ca3799, Jul 18, 2024 at 12:49 AM
  2. rjparker

    rjparker Tu Humilde Sirviente

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    The primary reason you need heavy duty 12v cables is the 80-100 amps you are drawing. 100 amps at 12v needs the same size wires as 100 amps feeding your house. Look at 12v starter cables in a conventional car. 100 amps minimum.
     
    #2 rjparker, Jul 18, 2024 at 1:07 AM
  3. Tombukt2

    Tombukt2 Senior Member

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    You want to do all this to avoid a generator interesting yeah it can work I have four of them I've never attempted it I also have a diesel generator that requires like no maintenance I don't know what kind of maintenance you're looking at for generators unless you run the hale out of em And keep them in the standing heat or something silly I don't know or your generator isn't rated for what you're doing with it not electrically but conditionally. Most generators you want going to have at your house you want to have them maybe in the shade some kind of a sunblocker over them to the side of them so they're not sitting and running it $299° because well they're sitting in the direct sun things like that go a long way to not doing lots of repairs and things like that running gas to me is a no-no for a generator and generators the world runs on diesel like the military I have a prime 20K they can run as a power plant until it blows up essentially like what the military uses You can buy these things for 3 grand and they can run and run and run and run in American conditions these things are rated to run in 140° weather 24/7 but in a lot of places you folks live you can't have these they would either be too big or there would be something in your HOA that wouldn't allow it because it's big enough to power your whole house or they don't like the wheels on the trailer or it has a star on it who knows. I also have a roll cage generac 10K on old one before all the generac problems works very well and never been the service per se.
     
    #3 Tombukt2, Jul 18, 2024 at 5:43 AM
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