Q: I live in a small condominium and not long ago went through an extended power blackout. The building has no generator and there is no way for me to use one. I’d like to be able to use batteries to operate some appliances during a blackout — a small electric heater, refrigerator, microwave and so forth. Is this possible?
A: It is possible to run some appliances with batteries, but it might not be practical in a small condo. The main problem, of course, is that most household appliances run on alternating current (AC), while batteries produce direct current (DC).
In order for the two types of current to be compatible, a device called an inverter can be used. Power inverters in several wattage ranges are sold at some home centers, department stores, and on the Internet (the more wattage the better). Prices for inverters are reasonable. An inverter is connected to a 12-volt car battery, and extension cords or appliances plug into the inverter. Researchers for Consumer Reports magazine tested inverters to run appliances such as refrigerators, sump pumps, lights and television sets, and reported good results.
If that paints a rosy picture, there is a catch. Batteries hold a limited amount of power and will rather quickly become useless unless recharged. An inverter hooked to car battery is usually kept charged by running the car at idle, which lets the car’s charging system keep the battery powered. Batteries can also be kept charged with plug-in chargers, but that won’t work in a power blackout unless the battery and charger are hauled to a place outside the blackout area.
If you still want to try battery power for AC appliances, I recommend spending some time on research before spending any money on equipment. A fine place to start is Consumer Reports magazine, which had several articles on the subject. Many public libraries have searchable files of Consumer Reports.