Most decent way to run your 115V essentials out of Prius Prime

Discussion in 'Prime Technical Discussion' started by Krzysiek_KTA, Jun 7, 2020.

  1. m8547

    m8547 Senior Member

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    Good to know about the overload protection. 2kW is definitely too high for the Prius, but I would also like the ability to use the inverter in a separate small off grid battery setup.

    I'm thinking of using a 80 or 100A DC circiut breaker when it's hooked up to the Prius, just to keep me from accidentally loading it too much.
     
    #81 m8547, Jun 12, 2020
    Last edited: Jun 12, 2020
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  2. jerrymildred

    jerrymildred Senior Member

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    Good explanation. Most stuff will kind of run, but might not run reliably. It'll run hot. There'll be noise. I wouldn't use one long term, so if I'm getting one, I need pure sine wave.

    In the factory, our variable speed AC drives used PWM to make a much closer approximation of a sine wave. Awesome devices. But they did make some electronic noise.
     
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  3. Krzysiek_KTA

    Krzysiek_KTA Active Member

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    I fully agree 1000 W is a max Prime DC-DC and fully charged battery can handle. I noticed that on startup of the inverter with loads connected, the power draw went as much up as 1450 W at one instance and the battery voltage dropped down to 11.1 V . With loads over 750 W the battery voltage keeps just above 13.1 V otherwise in the range of 0-500 W it stays above 14 V

    BTW. In comparison when I hooked the same setup to my Bolt EV (has 1600 W DC-DC converter) the battery voltage never drops below 12.8 V and mostly stays at 14.4 V... )

    Also at one instance with loads at the level of 700-800 W the 80 W rated small chest freezer kicked in and caused the inverter to "choke" for a second and I lost continuous power supply to my essentials for that time. Not a big deal, but if u have internet gateway hooked up or doing some file transfers on your computer that might be troublesome. An UPS would solve that though (I guess).
    From my experience if you load the simple setup like mine with peak loads below 1250 W all will run flawlessly.
    Off course with much more efficient Xantrex inverter you might go beyond that, but with working 150$ setup to have essential backup is decent.
    BTW
    I tried before the non Pure Sine inverter setup - NO GO after 5 min testing - noise,l excessive heat and vibrations of fridge compressors..... Pure Sine is the way to go.
    Actually I noticed my French door 24 cf fridge runs much more smoother and quieter when connected to pure sine inverter in comparison to just being plugged to the grid.

    Hope sharing that will be useful for some folks on this very educative forum.

    Cheers!
     
    #83 Krzysiek_KTA, Jun 12, 2020
    Last edited: Jun 12, 2020
  4. Salamander_King

    Salamander_King Senior Member

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    Aha! You mean the regular gas/propane generator is not producing modified sine wave but something closer to the pure sine wave? That explains why I have not heard anyone who has an automatic back-up generator for the whole house complaining about not being able to use many electric appliances while on the generator. AFAIK, the largest inverter generator that produces pure sine-wave AC power is only 4000W, but most typically 2000-3000W. I have seen people using two 2000W HONDA inverter generators connected in tandem to generate 4000W, but that can get very expensive. And that is still not enough power for most whole-house back-up. I need minimum of 7500W for my house. As I said, I have used almost every electronic appliances regularly connected to the wall outlet including TV, stereo, laptop, modem, printer, refrigerator, microwave, etc during a power outage using a portable gas/propane dual fuel generator without a problem. The only thing I have not tried is charging PRIME.
     
    #84 Salamander_King, Jun 12, 2020
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  5. m8547

    m8547 Senior Member

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    Try hooking up the negative terminal of the inverter to something else besides the negative battery terminal. Even the second lug just behind the battery terminal would work. That lets the car sense the current, and the DC-DC converter might be able to keep the voltage from dropping so much. I'm planning on experimenting with that at some point.

    100A is the max for the converter, but I think momentarily higher loads won't hurt it.
     
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  6. fuzzy1

    fuzzy1 Senior Member

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    Yes.

    A big utility 2-pole machine should be a nearly ideal sine wave. I won't speak for the slow-spinning many-pole machines, but they should be quite close too. None of them should produce anything remotely resembling the waveform of an MSW inverter.
     
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  7. Salamander_King

    Salamander_King Senior Member

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    If that is the case, what is a big advantage of those expensive inverter generators that cost at least 2-3x more than regular generator for the same power?
     
    #87 Salamander_King, Jun 12, 2020
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  8. jerrymildred

    jerrymildred Senior Member

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    Correct on the rotating generators. But they still have the potential of fluctuating frequencies as they try to adjust to the variation in loads as motors start and stop. Even the 50kVA 3-phase generator we had at the radio station would fluctuate a little bit. But only a very little bit.
     
  9. fuzzy1

    fuzzy1 Senior Member

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    Voltage and frequency regulation.
     
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  10. Salamander_King

    Salamander_King Senior Member

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    So, would voltage and frequency fluctuations hurt the ordinary electric appliances in a normal household, especially when they experience very seldom like once a year for maybe 1-2 days?
     
  11. fuzzy1

    fuzzy1 Senior Member

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    It depends on how big the surges and sags are as appliances turn on and off. I don't have a good answer for any specific power level.

    The little 1000-2000 W generators, with little motors, will experience load switching equivalent to nearly their full capacity. Put a light bulb on the output too, and it will brighten and dim with the surges and sags of the big loads. Other motors could slow down too much as frequency drops on a sag. With multiple appliances driven at one, the mutual interference may be disconcerting to the users, possibly even prevent proper operation of some of them.

    The 7500 W and larger generators will experience smaller fractional load changes, driven by larger motors. (Except when an electric water heater or drier cycles on and off.) They will have less need for inverter regulation.

    I'm not an expert on this, haven't yet shopped in this market, so you'll get more detail from someone closer to this market.
     
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  12. Salamander_King

    Salamander_King Senior Member

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    Thank you. It is a good enough explanation for me. We don't have an electric water heater but do have an electric oven and electric dryer. Those two appliances are off-limit during a power outage in our house due to high power consumption on the relatively low power generator. Even with those two large ticket items off-limit, I do see power drag on the generator when our deep well pump kicks in. Yeah, rather than investing in a very expensive smaller power inverter generator, maybe I should look into an even bigger regular generator for my house.
     
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  13. Krzysiek_KTA

    Krzysiek_KTA Active Member

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    Thx for comments. I think the setup I have with Prime does job to the best I tried, But in case of hooking up the Bolt EV o inverter your input might matter.
    Cheers!
     
  14. CharlesH

    CharlesH CA HOV Decal #5 on former PiP

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    The experts can correct me, but my understanding is that the cheaper alternators are outputting pretty much exactly what is being produced by the alternator that is directly connected by a shaft to the gasoline engine. So the gasoline engine has to be kept running at a fixed specific speed so you get 60Hz AC out. But more expensive alternators take whatever garbage that is coming from the engine-driven alternator, and use electronics to produce nice clean 60Hz AC. Kind of like how the inverter in the Prius takes DC from the battery and produces nice clean AC for the electric motors. The speed of the gasoline engine can be adjusted to make it more efficient.
     
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  15. alinica2001

    alinica2001 Member

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    That doesn't sounds right. If you have 1kw load, that should eat AT LEAST 1 kw from your traction battery. As the useful energy in your battery is around 6KW, you will end up with ICE being started after less than 6 hours with a load of 1kw...
     
  16. Salamander_King

    Salamander_King Senior Member

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    You are comparing kw (power) to kWh (energy). In OP's statements, I don't think he is implying using 1kW load (=power) continuously for 12-14 hours. If he is, then you are correct that the battery is depleted in less than 6 hours, but most appliances do not use peak power continuously. 1kW in OP's statement is a max load the inverter he used can handle at any given time.
     
  17. ChapmanF

    ChapmanF Senior Member

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    That's pretty much how I'd say it, except maybe for the garbage part. What's coming from the engine-driven alternator is probably a pretty nice sine wave; that's pretty much what you'll get if you put magnets on a round thing and spin it.

    It just won't always be 60 Hz, depending on the engine rpm.
     
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  18. Salamander_King

    Salamander_King Senior Member

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    I tried Seek x5 and Track x5, but could not invoke the diagnostic screen. How do I turn off the screen completely? In my 2017 PRIME with a large 11.6 inch screen, I had the screen off from the display setting. I had it turned off most of the time. Now with 7 inch display not as obnoxious as the larger one, I have kept the screen on, and have not figured out the way to turn it off.

    BTW, I drove my prime first time this month. In fact, the last drive was over three weeks ago. Here is the 12v battery voltage during my drive today. I did a total of 37 miles but had to stop and run several errands in town. It was not a continuous drive. But as you can see the charging voltage for each section of the drive was always starting at above 14v. My 12v before the drive was 12.51v and after the drive, it was 12.58v.

    upload_2020-6-15_19-56-23.png
     
  19. fuzzy1

    fuzzy1 Senior Member

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    The stuff coming directly off the alternator won't necessarily be of the right voltage either, especially with changing loads through its non-negligible impedance. The electronics in an inverter can clean that up too.
     
  20. ChapmanF

    ChapmanF Senior Member

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    Right. But clean though. A nice clean sine wave ... of some frequency, and some voltage.