Anyone Using Electric car as storage battery

[montreid]

Have a grid-tied 4kw PV net metered system in SoCal and driving two EV cars. With new rates coming, was thinking of adding Powerwall option.

Thinking: But how about the 30+ kw battery that's sitting in my driveway in the evenings? why can't I use that to power the house for the 3 hours 6p-9p and then turn around and charge from 12mn to 4am? Yes, it cycles out the battery deeper, but it's still cheaper than buying another set of batteries (and environmentally friendlier).

Anyone been able to do this? My non-electrician brain thinks that powerwall is just a non-mobile tesla battery. Thoughts anyone?

[DanKegel]

Great idea, but looks like it's not mainstream yet?

See http://www.nrel.gov/transportation/p...tegration.html for a teaser on the topic that mentions some equipment.

[SunEagle]

Maybe someday an EV could be used to store solar power but the hardware to make the circuit work is really not that common or as far as I know even available. Although I am sure someone has an experimental system that they feel works well but may hurt the EV's overall performance and not really save any money.

[Sunking]

Can it be done? Yes.
Has it been done? Yes

The question is how. You have 3 issues:

1. Vehicle Warranty void.
2. Fabrication of an Interface Device to access the EV battery. Dead give away to dealer and voids your warranty.
3. Is the show stopper. Just try to find an Inverter that can use an EV high voltage of 300 to 500 volts. Good luck with that one.

Who as done it? Mostly by people who build a DIY or Custom EV. Those guys use lot lower voltages than commercial EV's in the range of 48 to 144 volts in 12 volt increments which there are many Inverters available on the market. Also no warranty issues as they use standard used vehicles as a donor car out of warranty.

[DanKegel]

Maybe someday an EV could be used to store solar power but the hardware to make the circuit work is really not that common or as far as I know even available.

Oh, it's available in Japan; Nichicon sells one there called the EV Power Station (though most posts about it seem to be from 2012 and 2014).
Nissan seems to like them; they're even working with them to arrange for Nissan's hydrogen vehicle to serve as a generator to power a house, see

http://www.nichicon.co.jp/english/product_news/new145.html

It's just, well, everybody has bigger fish to fry in the US, like getting EVs adopted at all, to worry about cool other ways EVs could be used. I think.

[santaclaws]

I was searching the forum for some news regarding battery technologies and I came up with this thread too.

Just a quick thought: what about using the car 12V socket(s) to run an inverter? This way, you're not voiding any warranty and you could suck enough energy for regular evening activities.

[littleharbor]

As long as your regular evening activities don't require more than 2-300 watts. Any sizable inverter needs large cables supplying DC voltage from the battery source. Any inverter that comes with a cigarette lighter plug should be of minimum output and likely will be of minimum quality.

[peakbagger]

On one of the forums there is an individual who uses a prius to run his house when the power is out. He hooks the Priius battery to a computer UPS which is specifically set up for the Prius battery voltage. I expect that the big challenge is getting a charger that will integrate with the vehicle charging system

[SunEagle]

On one of the forums there is an individual who uses a prius to run his house when the power is out. He hooks the Priius battery to a computer UPS which is specifically set up for the Prius battery voltage. I expect that the big challenge is getting a charger that will integrate with the vehicle charging system

My hope is that someone will start to manufacturer more equipment to allow the use of an EV battery as an emergency power source.

The big problem I see is that using the EV battery that way will probably shorten it's useful life and IMO those batteries cost a lot more then an FLA system to replace.

[santaclaws]

Why do you think that a ridiculous load (few hundred watts) would afect the EV battery?

After all, by using the 12V socket you're not by-passing any battery control system hence no harm could be done.

By the way, there are many quality sine wave inverters available for 12V input (500W - 1kW range, by example).

[SunEagle]

Why do you think that a ridiculous load (few hundred watts) would afect the EV battery?

After all, by using the 12V socket you're not by-passing any battery control system hence no harm could be done.

By the way, there are many quality sine wave inverters available for 12V input (500W - 1kW range, by example).

Like any battery, they have a designed lifetime of cycles or partial cycles. While I agree that a minor discharge to a remote load from an EV battery would be similar to using the AC or some other electrical load that is in the car but how does that battery usage affect the number of life cycles before it needs to be replaced?

On the other hand if you decide to use more than a few hundred watt hours out of your EV for a remote load in the home, the question you have to ask yourself is, will there be enough power tomorrow when I have to use my car to get to it's destination? Except for a very few models (like Tesla) the round trip range of the battery is pretty small.

[santaclaws]

Well, the OP question was about "borrowing" some power from the EV battery during evening (or for an emmergency on that matter).

I also think that an EV battery is rugged enough to ignore (aka not counting for cycling) such a small load (for only few hours).

The OP said that the battery would be put on charge during night anyway so the "damage" should be minimal.

[J.P.M.]

Well, the OP question was about "borrowing" some power from the EV battery during evening (or for an emmergency on that matter).

I also think that an EV battery is rugged enough to ignore (aka not counting for cycling) such a small load (for only few hours).

The OP said that the battery would be put on charge during night anyway so the "damage" should be minimal.

Does anyone have any real, unbiased, vetted, technical or experiential information on this subject ?

[littleharbor]

Why do you think that a ridiculous load (few hundred watts) would afect the EV battery?

After all, by using the 12V socket you're not by-passing any battery control system hence no harm could be done.

By the way, there are many quality sine wave inverters available for 12V input (500W - 1kW range, by example).

Where do you intend to tap your 1000 watts from? I seriously doubt any wiring running a 12 volt port in autos is up to carrying that much amperage.

[santaclaws]

I've just mentioned the availability of those inverters.

Using an 1kW inverter doesn't mean you have to run it at full power (we're talking about surging 3-400W only).