Kona as a backup battery for home power outage?

Discussion in 'Hyundai Kona Electric' started by Jgood, Nov 5, 2019.

  1. Paul DeLeon

    Paul DeLeon Member

    Thanks. With this knowledge I'm going to buy a 1200 Watt pure sine wave inverter, attach it to the battery if we get a power failure here in central CT,
    and plug in my electric blanket.
  2. milesian

    milesian New Member


    Hey what do you think of this unit? It claims to be able to charge 1300Wh in under two hours, wow, so it can take most everything the Kona 12V can throw at it. Feels like it can be an ideal backup scenario for us.

    Thanks for breaking things down for me. Other than much lower continuous/peak output than something like the EcoFlow Delta linked above, are there more disadvantages to the inverter-only setup you suggest?

    Also thanks for letting me know about the Vue. I bought one and can't wait to play with it.

    Everything is gas for me in the winter, both water and heat, and no pumps or anything. So you're right, for emergencies I can likely get by even on the Kona 12V alone. That said, maybe something more powerful like the above 1800W/3300W EcoFlow is still a prudent choice, especially if it can really be recharged by the Kona at the rate that it alleges. Penny for everyone's thoughts.
  3. So the ecoflow is basically a 100 amp hour lithium battery connected to an inverter/charger. It has a 1800 watt output so it makes about 5 amps more than connecting an inverter straight to the Kona battery. Not sure its worth a grand for that. Also eventually you will reach a steady-state where what your putting in from the Kona is what you getting out of the ECOFlow. The only real advantage is the surge capacity. For that I would just buy a couple of deep cycle batteries to connect in parallel with the Kona battery and hook the inverter to the deep cycle batteries. This will cut the draw from any one battery including the Kona and its charger while providing short term surge capacity for running things such as running the furnace and the refrigerator simultaneously then when the surge settles the Kona will bring the charge back up on all the batteries.
    milesian likes this.
  4. pmarks

    pmarks New Member

  5. Jgood

    Jgood Member

  6. Yeah I don't think I would be too excited about using a battery pack that currently has a $30K+ replacement cost + $4K for an bidirectional EVSE, while a much cheaper ICE generator or even a couple of dedicated Powerwalls will do it with much less financial risk. I could also see Hyundai not exited about this from a warranty perspective.
  7. Jgood

    Jgood Member

    Apparently Nissan already has a certification program in place for companies that want to build products that utilize their battery pack. I'm willing to bet that every car BEV manufacturer will have something like this in less than 5 years. Especially since this is an emergency back up. We're not talking about people running their daily lives off their car's battery pack. This is more like an ice storm power outage that lets people keep the lights on or their furnace operating. A household of frozen and broken pipes could do far more than $30K of damage. Plus the inverter in this thing only allows 7.4 kwh in EITHER direction. It's not likely to damage the battery if the power flow OUT is no greater than a level 2 charger IN. Hooking your car up to a DC charger is going to be far more stressful on your battery pack than running your refrigerator. As someone who lives in the northeast and deals with many potential storm related power outages each year, I'd buy-in a heartbeat.
    ehatch likes this.
  8. mikeselectricstuff

    mikeselectricstuff Active Member

    I would have concerns about using the connector that I use for occasional rapid charging getting the wear and tear of everyday charging.
    I can also see car makers being very wary of allowing (via providing software support in the BMS) this type of use due to the possible bad consequences of the full battery supply being available in a domestic environment. A damaged cable could be a major arc-flash fire and injury risk.
  9. The economics make no sense when you can buy a energy efficient Honda inverter generator for under $1000 to do exactly the same thing. Sorry I don't see it taking off at $4K but I could be wrong, wouldn't be the first time.
  10. bwilson4web

    bwilson4web Well-Known Member Subscriber

    Until the carbon monoxide fumes; frequent refueling, and; noise has to be dealt with. Add to that the failures to start because it was not run for several years. Then there is the cost per kilowatt hour.

    Pay me now or pay me later.

    Bob Wilson
  11. I would buy it. First it puts out 7 kw that's lot more than a Honda inverter generator. A 4 kw Honda inverter generator is around $4k. I have a 5.5 kw generator and it is noisy but livable. I have it running on propane off of a 250 gallon tank so it can run all day. I don't run it at night. I use it may be twice a year.

    With this product I could use it in conjunction with my solar and run indefinitely with no fuel costs, oil changes, emissions or noise. As far as the affect on the battery it uses about the same energy as cursing at about 50mph. I don't drive a lot of miles so using it for a back up for me would not cycle the battery any more than most on the site are with there normal driving.

    It may not work for everyone but it would for me.
    eastpole and ehatch like this.
  12. Jgood

    Jgood Member

    Yup. What you said. It would work for me too. I have a 10k solar array on my roof and with the Kona this would be a fantastic bundle.
  13. Of some relevance, this article and photo appeared on the FB group, frustratingly with no details.

  14. hobbit

    hobbit Active Member

    I'll bet that it's much easier to do this with CHAdeMO than CCS, for starters, just from
    the complexity of control protocols. On the other hand, this is what ISO-15118 is
    supposed to be for. Except that there are lots of vehicles already on the road
    that can't natively participate in this, so either they're hosed or Wallbox has come
    up with some clever workaround to convince DC-chargeable cars to at least
    turn on the big DC contacts and then not worry about current flowing in the
    "wrong direction". I'm going to try and get a question to the company as far
    as their expectations on vehicle compatibility. And what they do about
    islanding, transfer switches, etc.

    That output to "the grid" had better be real split-phase 240 with a proper
    neutral and ground, too, as it's going to see unbalanced loads and stuff
    that also needs 240 to work [like my heat pump]. There are quite a few
    ancillary things to think about for a real-life installation.


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