Anyone Using Electric car as storage battery

[inetdog]

On the Prius the 12 electrical system is not powered by a step-down converter from the traction (main) battery. It is a very small (30AH?) AGM battery which is recharged from the traction battery through a converter when the car is turned on.
If the Prius is off, the 12V system can easily be run down to the point where you will have to use a jump pack to provide enough 12V to the controls to allow the engine to be started.

Be careful!
On the other hand, you can leave the Prius on and the engine will only run when the traction battery needs recharging. I have done that quite comfortably using a 500W inverter connected to the jump start terminals under the hood. It is really hard to get at the battery terminals.

[bcroe]

Cigar lighter sockets are likely fused at no more than 30A, and I doubt the wire harness to it is more than 12ga. 30A @ 12V is 360w Trying to use one for more than the 30sec is was designed to heat the glow element, will most likely be disappointing.

Yes, they have issues. To make serious connection to a vehicle battery, I use Anderson 50A or 175A
connectors; may also have an EC3 for battery maintainer, etc service. Bruce Roe

[SunEagle]

I have a degree in electronics but you can show me some pictures to get it right.

So let me repeat once again: you can even use a 5kW inverter with a 2-300W load and no damage would be done to any cigar socket.

Btw, I have such a car (brick) inverter and I'm reading from its nameplate: 400W (650W peak). I've used it for about 10 years now on many cars, on any regular 12V socket.

Anyway, the whole discussion was about accessing some (2-300W) of the EV battery power without voiding the guarantee.

You may have a degree in electronics but IMO have no idea what is required concerning electrical power systems or the NEC. By the way the NEC does print a larger code manual that includes pictures to help explain what is in the text.

As I stated in the other thread. Regardless of what the inverter is rated the wiring must be protected by an over current device. Usually the wire can withstand very short duration high currents (which will get it hot) but not for long term or the insulation will melt and the leads will short. So while that inverter might handle 650watt the wiring won't for anything other that a short surge.

[littleharbor]

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.

As long as your "regular evening activities" don't exceed your plug in inverter's limitations you should be just fine,

Hooking up a 5000 watt inverter to a cigarette lighter plug would be a tad on the ridiculous side. The power consumption of a 5000 watt inverter at idle would likely equal a 2-300 watt inverter at full tilt., plus a 5000 watt, 12 volt inverter is just plain dangerous. 5000 watts @ 11.5 volts is 435 amps. What's the surge rating divided by 11.5 volts?

[santaclaws]

If you do not understand what I am saying then you need to go research electrical properties and design.

I have a degree in electronics but you can show me some pictures to get it right.

So let me repeat once again: you can even use a 5kW inverter with a 2-300W load and no damage would be done to any cigar socket.

Btw, I have such a car (brick) inverter and I'm reading from its nameplate: 400W (650W peak). I've used it for about 10 years now on many cars, on any regular 12V socket.

Anyway, the whole discussion was about accessing some (2-300W) of the EV battery power without voiding the guarantee.

[Mike90250]

Cigar lighter sockets are likely fused at no more than 30A, and I doubt the wire harness to it is more than 12ga. 30A @ 12V is 360w Trying to use one for more than the 30sec is was designed to heat the glow element, will most likely be disappointing.

[SunEagle]

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 3-400W).

Even with 400 watts you need wire sized for #10AWG for very short runs and much larger for longer runs.

[SunEagle]

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 3-400W).

A 1kW inverter at 12volts could draw over 80 amps. Those plug in type can handle maybe 15 amps. You would have to find a way to tap the 12volt distribution bus in the EV and connect the appropriate wire including fusing to run that inverter.

If you do not understand what I am saying then you need to go research electrical properties and design.

[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).

[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.

[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 ?

[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.

[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]

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]

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.