I was talking to my aunt about generators and she brought up the idea as using the car with a inverter. Would this work? Why or why not?

I've heard that a modern car or truck in neutral or park will drain its own battery rather than charge it, due to the large electrical load and the limited (i.e., efficient) power output of an idling vehicle.

That doesn't answer your question, but it's food for thought.

Sure it'll work, and work well, but it is an expensive way to power your batteries. I have never made the test, but I'll bet that most any car will use 5 times the gasoline for the same running time as a good generator.

I've done it before during a power outage. I used my truck and a 400 watt inverter to watch TV and power a few lights. It's better than nothing.

This is how I watch movies on my laptop during long road trips.

we ran a laptop , a movie projection thingy shooting the laptop movie onto two 4x8 sheets of white board on the side of a dump trailer, stereo reciever for sound that was powering 2 stage type speakers. With an inverter run off a kawasaki mules battery out in the middle of the woods so we could watch an 8x8 screen of Apocolypse now ... While it will not power a house it will definatly run some creature comforts like a couple light bulbs for you or somththing.

Bigger inverters get expensive quick and dont put out the power of even cheap generators. 2 yrs ago we got two 6000 or 6500 watt gen sets ( one for each camper/ race trailer)  from home depot for well under 400 each. I think mine I paid like $347 and big Bill got his a couple months after me for $325 or so with subaru motors. Im pretty sure somthing like a 1500 watt inverter is $250+

Here are some examples I found

5000 watt inverter $749.99
http://www.northerntool.com/webapp/wcs/stores/servlet/product_6970_200380045_200380045

ETQ Portable Generator — 6000 Surge Watts, 5250 Rated Watts  $ 499.99

My gen set runs the inside and outtside lights on my little RV plus the AC , fridge , microwave , tv and a dvd player. With halogen lights on the trailers roof running and  floresant tubes on the trailers roof all running at once.

Here is a page with some running watts for appliances ect http://www.gillettegenerators.com/sizing/sizing02.html

If you shop around you can find a low cost generator that will atleast give you some form of comfort. We used mine when we got a flood here and it saved out behind. THe RV was 2 1/2 hrs away stored. While the gen set didnt power this 2 family house fully It provided heat via 3 electric fan type heaters a single fridge a few lights and a tv with dv players to kill time PLUS the sump pump to keep the basement from getting deeper then 4ft of water after the POS electric company shut the street off.  We used a propane stove for cooking and faired alright. Really other the internet we had everything we needed to be comfy  ( heat and hot food)  Especially with my elderly grandmother who was 93ish at the time.

To an extent you can do this, but you are limited in how much power you can pull out.

You can look up the alternator output of your specific vehicle and I don't know what the alternator would put out at idle.  I doubt it is full output but since I no longer work on vehicles for a paycheck I forget what idle output usually would be.

You will have to include the electronics on the vehicle, computer perhaps, electric fuel pump, and what ever else is running.

Now with the big battery used to start your vehicle you might be able to run some big stuff for a short time period but if planning to do this for a lot of hours you need to keep things to a level that allows the alternator to keep the battery happy.

I disagree with the statement about a vehicle idling will kill its battery.  I work corrections and we kill a lot of alternators in the life of a vehicle but at idle you can turn on everything and not wind up using more electricity than the alternator can produce.

This is in stock state vehicles.  I am sure some special cases may exist, but it sure is not common.

Overall it is an inefficient way to go about getting things done.  It can be a tool in the tool box, but it uses a lot of fuel for the power output and it puts your vehicle at risk since a lot of vehicles do not handle idling very well and you will get fuel washing past the rings and contaminating oil and shortening the life of the engine.  And as I mentioned we go through a lot of alternators at the prison.

But it can be used.

Just understand what your vehicle can do and be smart about it.

You might also want to run a search on the prius as a generator, since hybrids often have a lot more battery than a regular car you might find other possabilities with oddball vehicles.

you should double your idle speed.  The alternator output is speed dependent.  The fuel consumed is load dependent.  So, an in engine in Park or Neutral is only trying to over come internal friction and pumping losses (the suction of feeding itself through throttle and intakes)

So, if you run your engine at 1200 RPM vs 600 your fuel burn may go up about 10%, but your alternator output will almost double.  So, put a tiny weight on the pedal like a book etc, experiment.  ligths and AC/heat off, everything.  Have an extra battery or two on a cart to charge.  Deep cycles, this will get you the most bang for your buck.  Then you can run things off of your little battery bank.

YOU must watch your alternator or battery gauge if you have one, voltmeter will work also.  If you are running under about 13 volts when doing any of this, you are going to end up with a dead car......  This can really suck in a bad situation.  Overall, using the car to charge batteries or run an inverter is the least efficent of any option you will have, but you should know how to do it right.

A good rule of thumb, that accounts for almost every gas powered car in the US is 1 gallon of gas per at idle.  Most are closer to 0.6 GPH, but plan on 1 gallon, plus a little extra when you increase the RPM.

did it for few days during and after a hurricane. Montero (4cyl) in back yard, iidleing all night and 1200 watt inverter running two pumps in my basement and twice a day, the referigerator and freezer. did not run out of fuel. 16 gallons and 30+ hours of running probably made the monty more fuel effient than a bigger genset. idle a car for that much time is not good for it (cylinder wash issue) but it was a 1989 with 170k and did not seem to hurt it.
ADAPT and OVERCOME.
Update is we bought a 2400 watt Yamaha inverter generator and use that now.
thanks
tj

I was lucky enough to have an excellent supply of freebie stuff on my last tour out here. I have a pretty big 12v to 110v inverter that I got for free. I am thinking, with the extra battery tray in my pickup, I wouldn't have to worry about making room for it. Not sure if it would hold up under the amount of heat in the engine compartment, though. It has 2 outlets, which is the same number as my dad's generator has.

We used a spare auto starting battery to power a 500 watt inverter during a power outage. When the low battery alarm on the inverter beeped we ran a long set of jumper cables thru the cat door to recharge the battery. Once the idle picked up and you knew the battery was full we shut it off.

Car only ran for 60 minutes of the 23 hour outage.

Gas fireplace provided heat, box fans moved it around the house. TV and DVD player were used as well on the inverter. We kept the fridge cold with water bottles set on the porch to freeze. Main room in the house was 74 degrees and the coldest room was only about 60 degrees.