Using your car as a generator : LUSENET : TimeBomb 2000 (Y2000) : One Thread

Isn't it possible to utilize the battery charging capability of an auto to generate power for small appliances? Are there ways to tie into the battery power via an AC hookup?

I think I've seen this done before and it might be a nice, inexpensive alternative if you are like me and you just can't afford a generator. Anyone with expertise know about this? Your information would be grately appreciated.


Mike ================================================================

-- Michael Taylor (, November 06, 1998


Mike, Radio Shack carries a device called a AC/DC inverter that plugs into the cigarrette lighter and becomes an elect. outlet . prices range $230 $150 $80 Someone else (on this forum) mentioned Walmart very recently.

-- Arthur Rambo (, November 06, 1998.


has inverters designed to do this, and they're fairly inexpensive to boot...

Arlin Adams

-- Arlin H. Adams (, November 06, 1998.

You can do it, using either of the above.

Think about the local situation first, and as things change between now and 2000 - we don't know availability of gasoline (then), nor how long the troubles may last until gasoline service resumes.

You will be be the only qualified judge about your transportation needs; so I'd recommend you plan carefully using transportation gasoline for "electrical power supply" gasoline via your car's engine - if it is available, go ahead - there is nothing technically wrong, but the extra extended idle time on the engine should be considered. It will be like driving slowly in rush hour traffic, rather than heating up the engine normally and running at highway speeds.

For short periods (less than 1 hour - probably no lasting effects other than carbon buildup that won't get cured by some high-speed driving..

Anybody see other problems?

-- Robert A. Cook, P.E. (Kennesaw, GA) (, November 07, 1998.

There are major inefficiencies in the auto/alternator system for the suggested usage. (1)An alternator does not charge at idle speed, So the engine speed must be increased (brick on the gas pedal?) thus increasing fuel consumption (2) The engine/alternator combination is like harnessing a race horse to a toy wagon. I. E. 100+ hp engine yielding perhaps 1KW electrical power. In contrast, a properly matched genset can use a 20hp engine to generate 12KW. (3) The storage battery in a car is not designed for the deep discharge cycles/continuous current drain demanded by an inverter and appliances. This could shorten the life of the battery, incapacitating the car just when it's needed most. Check out the "Pedal Power" thread.

-- Elbow Grease (, November 07, 1998.

>An alternator does not charge at idle speed...

That can't be so. I've resurrected a dead battery many times this way - get a jump, idle for a couple of hours, and the battery's fine.

-- Ned (, November 07, 1998.

>>An alternator does not charge at idle speed...

>That can't be so....

Quite right. Please note that I was speaking of inefficiencies, not absolutes, tho my wording is unclear.

-- Elbow Grease (, November 07, 1998.

Thank you, Sir Elbow of the Grease,

I hope he understands, its not that electricity can't be gen'ed up this way, it's just not the best way to do things. But, I'm glad he's thinking of alternative alternators.

If he has a real big solar panel hooked up to the alternator - can he run his engine backwards and fill the gas tank?

-- Robert A. Cook, P.E. (Kennesaw, GA) (, November 07, 1998.

Friend of mine in KY hooked up an airplane prop to an alternator and connected it to a battery in his attic. Used the power for attic lights for several years. He just liked to tinker with such gadgets - I suppose you could build a charger like his if you didn't need much power. I think it would work better if you used a permanent magnet generator rather than a field coil alternator - I kind of think the field coils would drain the battery after several days with no wind.

-- Paul Davis (, November 08, 1998.

With the running auto/inverter setup, as long as you don't draw more current than the alternator can supply at the speed your engine is running, the battery is irrelevant (after all, you can remove the battery entirely once you've got the engine started).

The charge/discharge characteristics of the battery shouldn't be of concern unless you draw power with the engine NOT running, and thus discharge the battery.

As to the wisdom of the technique, as noted by "Elbow", it's a lot like "swatting" a fly with a sledge hammer, but the fly still ends up dead.

-- Hardliner (, November 09, 1998.

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