vh2q
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Using I Miev for backup power unit

Fri Dec 18, 2015 4:17 pm

Absent a 60hz "Powerbox" (and I am told by the mfg that the US cars lack the software in any case), how much power (in Watts) can you draw from the 12V battery using an inverter, under 2 scenarios
1. Short bursts (limited by the wiring/fusing I suppose)
2. Long term average (limited by the dc to dc converter I suppose)

I understand the car has to be turned on to ACC in order to avoid flattening the 12V battery. I read someplace the dc to dc converter is rated 80A at 14V which is around 1000W. But the manual also shows fusible links that may not support the full 80A.

PV1
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Re: Using I Miev for backup power unit

Fri Dec 18, 2015 6:48 pm

Yeah. I wish Mitsubishi would sell the Powerbox in the US.

If the car has 80 amp fuses, I would limit current to 70 amps or less. The car must be showing READY on the dash for the converter to be active.

To be safe, I wouldn't use any more than 800 watts.
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bennelson
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Re: Using I Miev for backup power unit

Mon Dec 21, 2015 7:30 am

I think an Open Source Vehicle to Grid project is something just waiting to be tackled.

Especially if it was designed so it could be used by iMiEVs, LEAFs, and all the most popular electric cars.

Not that I'm an electronics guy, but it seems like it would have to be through the quick-charge port, as that goes straight to the battery (instead of through the charger.) After that, the communications pins would need to be spoofed, but some folks have been working on DIY Chademo lately, so I think that's worked out too.

After that, there needed to be some high-power DC to DC conversion and the inversion to 60 hz AC power.

None of that actually sounds terrible complicated, but I'm not sure what the costs would be either.

vh2q
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Re: Using I Miev for backup power unit

Mon Dec 21, 2015 9:58 am

Mitsubishi says they are working on a US version of the powerbox, or at least trying to figure out whether there is any demand for it. Meanwhile I am going to try to draw up to 1000W through the 12V circuit (hook up to the 12V battery) and see how well that works.

Don
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Re: Using I Miev for backup power unit

Mon Dec 21, 2015 2:40 pm

The problem with the 'Powerbox' is . . . . Mitsu would want upwards of $2500 for it

Second problem would be . . . . if you're thinking of charging at night (when juice is cheap or even free some places) and then selling it back to the power company during the day would be that your iMiEV battery has maybe a couple thousand cycles in it and then you'd need a new battery pack. If you get your night time juice for FREE and you were somehow able to sell them 14Kw @ ten cents ($1.40 each 'cycle') and you did manage to get 2,000 cycles before your battery was shot, you'd have $2,800 for your effort - About the cost of the 'Powerbox' . . . . but far, far less than the cost of a new battery pack

I think the reason there's so little demand for the Powerbox is that it's only practical to use a few times per year in an emergency and it's do cheap (relatively speaking) to just buy a 5 Kw gas generator to keep your freezer frozen during a storm when the power goes out

Don
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vh2q
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Re: Using I Miev for backup power unit

Mon Dec 21, 2015 3:20 pm

Using this in Bahamas for backup only... the power goes out a lot and I need to keep fridge, TV, water pump and some lights (all on a separate emergency panel) on for up to five days ... and you can't sell power back to the grid in that country so no point in gearing up for that. At some point I would like to be able to charge my car from solar panels and run my emergency panel from the vehicle all the time, as electricity is v. expensive circa 50c per kwh. Then I would only need the grid for A/C in the summer as I already use solar for hot water. But I am waiting for solar panels to get cheaper and more efficient. Seems like they are around 20% efficient and cost around $2 per watt at the moment. 25% and $1 would be a more attractive formula. You need at least 1000W peak to charge the car and then you can get around 4 hours of charging time every day. So $1000 worth of panels plus the associated boxes (another $1000) and wiring. Powerbox doesn't seem that expensive in comparison.

Don
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Re: Using I Miev for backup power unit

Tue Dec 22, 2015 9:59 am

Maybe it's expensive to ship panels to the Bahamas? I bought a pair of 160 watt panels on eBay last month for my boat and the cost was less than $300, and that included shipping

A Honda EU2000i would do what you need when the power goes out - Especially if it's going to be out for several days. While it would be capable of doing what you envision, cycling your car battery in this manner would be very expensive in the long run - Much more than the cost of a small genset

Don
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jray3
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Re: Using I Miev for backup power unit

Wed May 18, 2016 4:23 pm

Some updated info on the Mitsu PowerBox today on the Seattle EV list. At current exchange rates, it sells for $1400 along with the car, but Mitsu won't sell them as standalone units. The instructions say that a software update may be required of the car for proper function. Nevertheless, here's a site listing 'em for sale.

When one considers that a 3D printed copycat CHAdeMO cable and handle runs $900, http://www.emotorwerks.com/index.php/st ... pathway-17
the PowerBox would seem a bargain, even though it only offers 1500 Watts.

What'll it take to convince somebody to produce a vehicle-to-home PowerBox for the US market? If CHAdeMO protocol has varied enough to prevent plug-n-play solutions, then it may be too much to ask a third party.
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JKO
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Re: Using I Miev for backup power unit

Thu May 19, 2016 2:48 am

Everybody talks about to charge with high power.
I want to charge with very low power directly from my sun panels.
So can I connect this Cable to my dc-dc converter (35v > 350V) an charge my car by using CHAdeMo port?
http://www.emotorwerks.com/index.php/st ... pathway-17

pbui19
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Re: Using I Miev for backup power unit

Thu May 19, 2016 7:06 am

vh2q,

your biggest advantage in the Bahamas is the abundance of solar insolation, you ought to be able to get way more than 4 hrs per day. You can get an idea of sun hours here by entering your coordinates, though am not 100% sure it'll work for the Bahamas:

http://www.sunearthtools.com/dp/tools/p ... hp?lang=en

so you don't really need a large array. A forum member here, Aerowatt, has a really nice set up using an external 12-v battery bank. The idea is to "trickle charge" the external 12-v bank, using the iMiev 12-v source and the PV. The external bank acts as a buffer for the high demand while constant getting small feed, sort of like the water tower in the old days. Obviously you can also charge the iMiev via a 12vdc->120vac converter using the level 1 charger. You can size the external bank accordingly for peak load while tapping the iMiev 15kwh pack capacity slowly.

Given there is about 1kw/m^2 at 0 latitude, the Bahamas at 25 lat, gets cos(25) ~> 0.9 kw/m^2, loads of power ! but you have to mitigate hurricane wind force...

sorry, i get carried away, sounds like a fun project. :D

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