Get 120-volt power on board just like at home.

If your boat is without a generator you’re stuck with 12-volt DC power like the cigarette lighter in your car—it’s fine for charging cell phones but it won’t work for a big screen TV. An inverter is the solution. Inverters take DC power from your boat’s batteries and turn it into AC power that you can use to power onboard electronics and appliances. Sensitive electronics like laptops and big screens are dependent upon the quality of the electricity used to power them. A modified sine wave output can result in poor picture and sound quality, and in rare cases cause a malfunction. An inverter such as Xantrex’s PROwatt SW offers true sine wave output, virtually free of higher frequency harmonics that often cause issues with sensitive electronics. How much electricity you want to produce and for how long depends upon how many batteries you want to carry.

Inverter technology has improved greatly over the past 20 years. In the early 1990s, a 2000-watt inverter weighed 100 pounds or more, and put out a modified sine wave form of AC current that was harsh on some electronics. While modified sine wave inverters are still offered, there are inverters now that put out a true or pure sine wave form of AC electricity that produces power like the 120-volt power outlet in your home. Pure sine wave inverters previously cost twice as much as modified sine wave inverters, but costs have come down dramatically in recent years. Today, the price difference is 10 to 20 percent more for a pure sine wave inverter, and the weight has been cut in half.

Inverters can be an efficient alternative to noisy generators that burn a lot of expensive gas or diesel. Inverters run silently, they don’t kick out any exhaust fumes and can provide up to 4.5kW of power depending on the size of the inverter and the battery bank you have on board.

To figure out how much power your battery bank will supply, simply find out the number of amp-hours the battery bank offers. Batteries serve as an energy source for 12- or 24-volt equipment as well as the DC power that the inverter uses to convert to AC power. The larger the battery bank— measured in number of amp-hours—the longer it will last.