Auditing Your RV Power Needs: A Guide to Designing an Efficient Solar and Battery System

Embarking on a journey in your recreational vehicle (RV) is all about freedom, adventure, and the thrill of exploring new places. However, to truly enjoy this lifestyle, it’s crucial to ensure that your RV’s power system is up to the task of supporting all your electrical needs. With the growing popularity of solar and battery systems in RVs, it’s time to audit your power requirements and design a system that meets your needs while keeping you off the grid for longer. In this blog post, we’ll walk you through the steps to audit your RV’s power needs and prepare for a new solar and battery system.    
Step 1: List All Electrical Appliances and Devices Start by making a comprehensive list of all the electrical appliances and devices you use in your RV. Include everything from lights and fans to kitchen appliances, entertainment systems, air conditioning units, and any other gadgets you rely on. Download a FREE energy audit worksheet on (Sign up for our newsletter on the home page pop up and you’ll get a download link) Step 2: Convert 120V to Watts
 Most RVs in North America operate on a 120V electrical system. To determine the power consumption of your devices in watts, you’ll need to multiply the voltage (120V) by the current (in amps) that each device draws. The formula is:
Watts (W) = Voltage (V) × Current (A)
For example, if you have a device that draws 5 amps at 120V, its power consumption would be: 
 W = 120V × 5A = 600W  
  Repeat this calculation for all the items on your list, and add up the total power consumption in watts.
 Step 3: Account for Daily Usage
To design an effective solar and battery system, you need to consider how long each device is used daily. Create a usage schedule, estimating the number of hours each device is in operation. Multiply the power consumption (in watts) by the daily usage time to find the daily energy consumption for each item. For instance, if your LED lights use 20 watts and are on for 4 hours a day:
Daily energy consumption = 20W × 4 hours = 80 watt-hours (Wh)
Repeat this calculation for all items, then sum up the daily energy consumption for your RV. Step 4: Factor in Inverter and Conversion Losses When designing a solar and battery system, don’t forget to account for losses during power conversion. Inverters and charge controllers are not 100% efficient, so you’ll need to factor in these losses. A common rule of thumb is to add 10-20% to your total energy consumption to account for these losses. Step 5: Determine Battery Capacity Now that you have the daily energy consumption with losses included, you can calculate the battery capacity needed. Divide the daily energy consumption by the voltage of your battery system (usually 12V or 24V) to find the required amp-hour (Ah) capacity: Battery Capacity (Ah) = Daily Energy Consumption (Wh) / Battery Voltage (V)
Step 6: Size Your Solar Array To keep your batteries charged, you’ll need to install a solar array that can generate enough energy to meet your daily needs. Solar panels’ output varies based on factors like location, orientation, and shading. Use an online solar calculator or consult with a solar professional to determine the number and wattage of solar panels required to meet your daily energy demands.