Build an Emergency Power Generator

Learn how to build a portable power station in case of a power outage from plywood, inverter and battery, including construction, operation, materials list and diagrams.

| February/March 1998

Less than 30 years ago, a power outage would be little more than a minor inconvenience to most people. Today, with the proliferation of home-business computers as well as answering and fax machines, a prolonged power interruption can bring your livelihood to a halt. Large cities are served by more than one electrical transmission line and most power outages usually last only as long as it takes to bypass a downed line, but country dwellers might well be stranded for days.

The most commercially available solution is a backup power supply system, but these stand-alone units (those in the $200 to $500 price range) will only keep a personal computer operating long enough to allow you to quickly save information and shut down. Not a terribly versatile solution.

This project will allow you to be prepared for the next short term power outage and maintain an almost normal life style while waiting for the line power return. The station cannot power everything in your home, but it will run a computer and fax machine, or television and DVD player for up to six hours, and lighting for several rooms at the same time ... and can be built for a total cost of less than $400.

The system is designed to be stored out of the way until needed, then serve as your first line of defense in an emergency. You can also extend the power stations usefulness; load it in the car and take it on your next camping trip, or use it to power small tools or lights at the job site when a generator is not practical.

System Description

The power station has been designed around a battery charger, a deep discharge battery, and a DC to AC inverter, all mounted in an easy to build wooden cabinet. Each component has been carefully matched in performance to provide a very efficient system in a very small package.

We have chosen a deep discharge 12 volt, 850 cranking amp capacity, lead-acid marine battery. Although two 6 volt golf-cart batteries wired in series will provide much better long term performance, the marine battery is sealed and is much safer to handle and keep charged in a confined space. Since this is the heart of the system, buy a quality battery rated for extended deep discharge use. A standard automobile battery will not provide satisfactory operating time and will fail completely after several deep discharge cycles.

4/29/2016 11:24:18 AM

I would rather buy a because there's less risk. When you buy one, its tested and ready to go. If anything, there's the option of renting one.

9/20/2015 6:37:11 PM

Unfortunately, this article is about 20 years old. (The first computer I ever bought was a Dell Pentium 100 - with Windows 95 - when purchasing these made made me an early adapter!) It is further unfortunate that Mother Earth News recycles a lot of these old articles that no one bothers to update, or, as you're finding out, even cares to reply to from the editorial staff!

9/16/2015 5:31:04 PM

My question is the same as Chucks. Just where do you get detailed plans for the larger emergency power generators. I see Chuck had no response looking at this articles web page so I would be grateful for some help on this. Greg

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