Understanding Inverters: When to Use, Features, Sizing for RVs

Author: Solar 4 RVs  

Understanding the Role of an Inverter in Your Power System

An inverter is a crucial component when you desire to utilize your 240V appliances without access to mains power. This device acts as a power transformer, converting the DC electricity from your battery into usable AC electricity.

Once an inverter is wired into your RV's 240V power system, you gain the flexibility to operate your 240V appliances using the electricity stored in your batteries. From powering your microwave to running essential appliances like an electric kettle, toaster, or hairdryer, an inverter makes it all possible.

However, if your power needs are limited to low power 12V devices such as LED lights, laptops, TVs, fridges, water pumps, or radios, purchasing and installing an inverter might not be necessary.

The Advantages of Pure Sine Wave Inverters

Pure Sine Wave Inverters are distinguished by several key features that improve the efficiency and performance of your electrical appliances:

  • Reduced current distortion leading to enhanced performance, especially for inductive load appliances like microwaves;
  • Minimized harmonic distortion, avoiding issues like flickering lights, lines across TV screens, or static on speakers;
  • Quiet operation for sensitive electronics, eliminating unpleasant humming or buzzing noises.

Choosing the Right Inverter Size

To select the right inverter, you need to calculate the power draw of your appliances in watts. Our guide can assist you in this process. Additionally, it's crucial to account for the start-up surge of your appliances, which can be 2.5-3 times their rated running watts.

If you're planning to run multiple appliances simultaneously, make sure to add up their total watts and account for the combined start-up surge. Note that an inverter's rating may be lower at higher temperatures (e.g., at 40 degrees).

Interpreting Inverter Specifications

Generally, inverters will specify two key values:

  1. Continuous Power Watts: The sustained power output the inverter can provide (e.g., 1000W).
  2. Peak Power Watts: The maximum power output available for brief periods (e.g., 3000W).

Your appliances will each draw a certain amount of power while running. As long as their combined power draw stays under the continuous power wattage of the inverter, everything will function smoothly.

Assessing Battery Capacity

It's essential to ensure that your battery capacity is adequate to supply the required power, particularly during power surges. After choosing an appropriately sized inverter, refer to the manufacturer's manual for recommendations on battery capacity, cable gauge, and fuse size.

Installation Guidelines

The inverter should be installed in a dry area with sufficient ventilation and ideally close to the batteries to minimize voltage drop. Be cautious if you're connecting to existing lead acid batteries, as they can produce flammable hydrogen gas when charging. Any spark from turning on the inverter could potentially cause an explosion albeit unlikely unless in an enclosed space with heavy charging/discharging of the battery.