if you leave a car continuously running, how large an inverter can be placed on it to make electricity?

I am trying to find a cheap back-up option for portable batteries that are solar charged. Could a car with a 2L engine run a 4000w or 5000w inverter to give 240V electrical power?


I want to power a food kitchen in a caravan for 4-6 hours a day in summer at the beach. Later I would like to have enough solar panels and deep cycle batteries to do it mainly by solar, but want a cheap start-up option, and a back-up later on. Would a car be as fefficient than a generator if excess power was stored in a few deep cycle batteries.

1 Answer

  • 7 years ago
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    What you are interested in is the capacity of your alternator, not the horsepower of the engine itself-- unless you plan to drive an external generator off of the engine, e.g. using a PTO on a tractor.

    Unless you are using a vehicle designed for it, e.g. an ambulance or other vehicle with a large air or water cooled alternator, you are going to get something on the order of 50A at around 13V from the alternator, which is on the order of 650W.

    The alternator is not a power-heavy device. It's purpose is to supply the amount of juice needed to run a cars lights and electronics, and in modern engineering practice it's not going to be oversized. What you are thinking about doing is similar to buying a clock to plug in to a wall so that you can use the second hand and a pulley to try and lift a heavy piece of furniture. You are much better off just buying an electric motor that uses the same power source. In your case, unless you have a direct drive off of your engine, that means buying a gasoline powered generator:


    If you DO have something, like a bus, that has a larger alternator, I doubt that it will be cheaper to idle the vehicle's engine. Traveling food service that I have seen either rely on a gasoline powered generator like above, or run on propane, aka lpg--this is a great solution for lighting and cooking, and you might be able to find a good, used propane powered refrigerator/freezer for around $500.


    I found this, you might find it interesting:


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