For emergency power, such as during an outage, power inverters can be used with an extension cord to plug in electric appliances. Power inverters are an electronic device that converts direct current (DC) of 12 volts to alternating current (AC) of 120 volts for operation of household appliances.

These are commonly used for energy for domestic appliances like electric lights, kitchen appliances, electric tools, microwaves, radios, and computers.

With DC AC power inverters, energy stored in a battery is transformed to AC electricity for usage in wide variety of applications. While switching from direct current to high voltage alternating current, many of these convert with a 90% efficiency.

These are available in different models varying in watts and sizes. The different capacity options should your main consideration when choosing one.

As these mechanisms normally assume that the source battery is in good condition and fully charged, it is necessary that the engine inside the source vehicle be started at least once an hour for 10-15 minutes to avoid discharge.

There are three basic types:

1. Square wave have become obsolete and are not recommended due to their inefficiency, noise and harshness.

2. Modified sine wave are most popular and are commonly sufficient to run most devices.

3. True-sine wave produce from the public utility grid system and are best for sensitive electronics. The output pattern is equivalent to 60Hz grid power.

Determining the best to suit and meet your requirements appropriately requires a careful consideration on these points:

* Would you use it daily or on an occasional basis?

* How many electrical outlets do you wish to plug in? Choose the size that best fits your needs.

* Does the entire load exceed 150 watts? If yes, a direct connection (DC) to the cell needs to be established.

* Are you planning to use heavy-draw equipment? If yes, a large-capacity unit and direct connection is required.

- Right Size for Your Needs

Deciding the best or suitable size of power inverters requires addition of the wattage requirement of all the appliances that will function at the same time. It is always recommended to consider the higher figure as this ensures that the inverter will provide for all appliances safely.

Depending on the amp-hour capacity available, the length of time an inverter functions can be estimated.

- Type of Batteries Recommended

Actual time for recharging depends on the age and condition of the battery and the demand being placed on the equipment being operated by the inverter.

For 500 watts and larger inverters we recommend use of deep cycle (marine or RV) batteries that provide several hundred complete charge/discharge cycles. Start the engine every 30 to 60 minutes and let it run for 10 minutes to recharge.

When DC to AC power inverters are operating appliances with high continuous load ratings for extended periods, it's advisable to connect to a stand alone battery - not the one in your car.

If car or truck battery is excessively used, it's possible that it will drain to a point when it has insufficient reserve, so use an extra deep cycle one. Deep cycle batteries are capable of withstanding repeated drains and have the highest reserve ratings.