Choose the best inverter type for the equipment being powered, calculate the size needed, make sure it can physically fit and have the appropriate battery system in place before you install an electrical power inverter into an RV. Many small inverters can be self-installed easily, however, some larger models may require professional assistance for wiring and other considerations for specific installations.
A true sine wave output inverter is the most expensive type, but it produces exactly the same type of current found in 120-volt residential supplies and runs almost any traditional electrical device if the output wattage is sufficient. A modified sine wave inverter is much less expensive but may not work with all devices and can potentially damage some.
Users must add up the wattage of the devices that they intend to use with the inverter and choose one with the necessary amperage. Small items, such as cellphone chargers, televisions and computers, may require less than a few hundred watts; however, items such as microwave ovens, coffee pots or hair dryers can need more than 1,000.
Inverters of less than 1,000 watts are generally small and plug into one of the RV's cigarette or utility 12-volt outlets and provide one or more 120-volt electrical plugs. This type is portable and requires no special installation. Larger units must be wired directly to the battery system and are usually installed in a cabinet or closet and wired to one or more outlets in the RV.
The larger the inverter, the faster it drains the batteries supplying it, so matching the inverter to the available batteries or increasing the battery capacity is necessary for extended usage.