Power the house with MiEV battery?

Last I remember couple of years back Mitsubish has an interface to allow the MiEV to seamlessly be used a home backup/emergency power supply.
The catches were IIRR it was hideously expensive and not available outside Japan.

But recently in a reply to another thread of mine our moderator, JoeS, said --
"my electric car is powering my house (even though it's just a simple 12v inverter."

OK, Joe (or anyone else):
Details please?

Do I correctly infer that (a) you just clipped an inverter onto the little 12 volt MiEV battery and (b) that the MiEV automatically uses energy in the main traction battery (as long as some is available) to keep the 12 volt topped up? Even when parked?

In any case raises questions?
How many watts can one safely draw out of the 12 volt without over loading its output or MiEV's ability to keep up with the drain. I infer (from the fact that when driving with lights on and heater running and that's got to be demanding quite a bit of wattage, which I _assume_ is all(?) coming out at 12 volts both to lights and the heater, that must be significant.

Joe.... What's been your experience with that kludge? What in the house can you run on it?
Do you just run an extension to a few items, or do you interface with or backfeed into your house wiring?

Alex

I think the DC to DC converter which charges the 12 volt battery from the 360 volt traction battery is rated at 75 amps, which is about 1Kw. I would limit that to 750 watts or so if you were going to use it for an extended period. The car can be parked, but it will need to be started and 'Ready' . . . . and the car will be using a bit of that power too - Maybe 500 to 600 watts would be a better upper limit

I've never thought of doing it personally - You have a vehicle which is essentially useless once it's traction battery is used up - Does it make sense to find another way to use up that battery while not driving the car? Maybe once in a while in an absolute emergency . . . . but I have a little Honda 2000i which will give me twice that power when needed in an emergency and it's cheaper to replace than an iMiEV traction battery

Don

Yeah Don,

I agree that using the MiEV as a whole house power supply isn't great idea. Let alone use it in a manner to drain it dead empty.
As you imply, during a zombie apocalypse it would be far better to keep the EV fully charged for transportation at a time when gasoline might be unavailable for many reasons than deplete it for one day's household power.
But for very short term to run some electronics (charge cell phones, keep the 'fridge on a tad) would be a lot easier than firing up the noisy generator (I have one too) .
But nice to have that option to bring into play as needed.

The cabin heater in the i-MiEV runs directly off the main battery, but all the HVAC controls and blower fan run on 12 volts. The A/C compressor also runs off the high voltage.

I've used my i-MiEV as a mobile battery before at events. It's easy to do. I take both keys, leave one in the car with the car READY, and use the second key to lock/unlock the doors (so nobody can just hop in and drive it away, but I can still get in). With the hood open and a small fold-up table, I hook up my 12 volt power inverter directly to the 12v battery and power up whatever I need to, staying under 400 watts total draw. The i-MiEV will stay in READY until the main battery goes to 0%.

As for the MiEV Powerbox, I haven't heard anything about it in several years. Last I heard in one of these conversations is speculation that NA i-MiEVs don't have the necessary firmware for one to work anyway.

Hi Folks,

Next month in Asheville there will be a Drive EV Day,
in a parking lot with no AC power.

I'm providing a small mixer, microphone, two-track interface and
a couple self-powered speakers.
The audio system will run off my 300W sine-wave inverter, connected to Maeve's 12V battery.

At modest levels, with no massive bass requirements, audio systems actually don't pull very much power.
Over the four hour event am expecting a drop of less than one bar.

Out here in the sticks we lose power for a few hours fairly often.
If it's hot and I want to keep the fridge cool I used to plug my 1000W inverter in to the truck.
Now I'll be using Maeve. (Fridge pulls about 550W.)

Thanks and good health, Weogo

Nice. Just a warning, though. You will lose at least one bar, more likely to lose 3 during that event. Don't forget that the car pulls a few hundred watts on its own when READY.

I have a set up with an external 12v 4kwh LiFe external pack to drive a 2000w dcac inverter. I can jumper the iMiev (or a Volt/Bolt) 12v to add charge to the external pack. But a recent test to power a 2 hoses portable ac/heater heatpump drew 120A on the jumper cable. Even a 6awg cable was getting warm. So I am now looking to limit that current in the jumper cable, probably with 60A "solar" charger.

PV1,

Good point about the watts pulled by the car in READY for four hours.
Across the street from the event there's a free 240V charger at the Ingles grocery store that will be getting me home!
Or I could spend the big bucks on Chademo.
Nice to have options.

Pbui19,
How long is that jumper cable?
For 12V, two meters of 4ga can do 120A with an acceptable 4% voltage drop.
To keep voltage drop under 5%, 6ga would be limited to about 1.5 meters.

Thanks and good health, Weogo

Hi PV1.

You wrote...
"...cabin heater in the i-MiEV runs directly off the main battery, ..."

I ,m confident you know more about the MiEV traits that I do.
And I’m curious about that statement:

If I remember right the main panel ready and set a very high voltage. Something like 330 V.
I'd find it surprising if the heater coils are fed 330 volts.
If so, a damn giid reason to not be tinkering anywhere near those leads with car, let alone heater, "live" if ever trouble shooting or mantaining relative to cabin heat. :?

Acensor, the battery can top out at 361 volts at full charge, so definitely want to be really careful when working with orange wires in the car as that voltage can kill.

The heater coils themselves might not run at that voltage, but the heater component does indeed get fed from the main battery, as does the A/C compressor. These loads draw too much power to run from the 12 volt system. The heater pulls 5,000 watts at full power, which would be over 360 amps if pulled from the 12 volt system.

WReed82, that's what I did, too. After the event, I drove back to my buddy's shop and charged from level 2 to make it home. Worked out great.

acensor said:

...But recently in a reply to another thread of mine our moderator, JoeS, said --
"my electric car is powering my house (even though it's just a simple 12v inverter."
OK, Joe (or anyone else):
Details please?
Do I correctly infer that (a) you just clipped an inverter onto the little 12 volt MiEV battery and (b) that the MiEV automatically uses energy in the main traction battery (as long as some is available) to keep the 12 volt topped up? Even when parked?
In any case raises questions?
How many watts can one safely draw out of the 12 volt without over loading its output or MiEV's ability to keep up with the drain. I infer (from the fact that when driving with lights on and heater running and that's got to be demanding quite a bit of wattage, which I _assume_ is all(?) coming out at 12 volts both to lights and the heater, that must be significant.
Joe.... What's been your experience with that kludge? What in the house can you run on it?
Do you just run an extension to a few items, or do you interface with or backfeed into your house wiring?

Click to expand...

OK, finally getting around to answering acensor's query, which has already been very ably responded-to by Don and others.

Here's the full quote of what I wrote -
"Love razzing my friends that my electric car is powering my house (even though it's just a simple 12v inverter running the fridge). If things get serious, I have the ability to hook up a lot of 48v battery packs and charge my cars if needbe, with Solar to recharge."

The first sentence is tongue-in-cheek, as when the power goes out what I normally do is plug in an inverter into any of the many different dc sources I have in the garage and then simply run a long extension cord to the refrigerator in the kitchen. I was surprised that my latest fridge only draws a little over 100W, with a 50% duty cycle.

No, I haven't modified my all-electric house to provide for a serious standby generator (battery-powered inverter) with isolation switch and dedicated critical wiring. The longest that power was out at my house was for around ten days after the 1989 Loma Prieta Earthquake, and we did just fine as I brought my ancient MBZ L206D British camper conversion close to the kitchen and used its cooking facilities in addition to a propane camping stove in the kitchen.

I have given some serious thought to this and am still in the process of building a solar trailer with huge 48v battery packs and large inverter(s) that will enable me to not only power some of the house but also charge my electric cars if a serious calamity should knock out the grid. For now, I'm ok as I can kluge something together (as long as my garage is still standing) :roll:

So, back on topic and to answer the original question regarding our i-MiEV as an energy source: even though it could provide much more power, I personally wouldn't want to draw more than about 100W out of an inverter hooked up to our i-MiEV 12v battery (the car in READY), especially nowadays as our OBC/dc-dc is proving to be iffy.

Hi JoeS,

"even though it could provide much more power, I personally wouldn't want to draw more than about 100W out of an inverter hooked up to our i-MiEV 12v battery (the car in READY), especially nowadays as our OBC/dc-dc is proving to be iffy."

Ah, I see the light.

For the EV expo I'm going to pull the big AGM battery out of my truck for powering the sound system.
This has the added benefit of freeing up Maeve for ferrying interested folks around the parking lot.

Thanks and good health, Weogo