DIY Solar for RV: Build Your Own System for Under $1800

Why RVers Go DIY Solar

Generators have been the default off-grid power source for decades, but they come with serious drawbacks that solar eliminates:

• Boondocking freedom. Most BLM and national forest dispersed camping areas have quiet hours and some ban generators entirely. Solar runs silently 24/7, meaning you can stay as long as the 14-day limit allows.
• No fuel costs. A generator burning 0.5 gallons per hour at $4/gallon costs $48/day for continuous power. Solar panels pay for themselves in weeks of full-time boondocking.
• No maintenance. Generators need oil changes, spark plugs, air filters, and winterization. A solar system has no moving parts. The panels will outlast your RV.
• No noise. Even “quiet” inverter generators run at 50-60 dB. Solar is silent. Your neighbors at the next campsite will thank you.

Building the system yourself saves 30-50% compared to having a shop install one, and you will understand every component when something needs troubleshooting on the road.

Typical RV Power Needs

Before sizing your system, you need to know how much power you actually use. Most moderate-use RVers consume 400-800Wh per day. Here is a typical breakdown:

If you add a coffee maker (1000W for 5 minutes = 83Wh) or a hair dryer, your daily total climbs quickly. For heavy AC loads, you will need a larger inverter and battery bank. Use our DIY System Builder to size a system for your exact load list.

Recommended System Components

For a moderate-use RV pulling 400-800Wh per day, here is the system we recommend:

Step-by-Step Build Overview

This is a high-level overview of the installation process. Each step deserves careful planning and research before you start drilling holes in your RV.

1. Plan your layout. Decide where the battery, charge controller, inverter, and fuse box will live. Most RVs have a dedicated battery compartment. The charge controller should be close to the battery, not the panels.
2. Mount solar panels. Clean the roof, apply mounting brackets with Dicor self-leveling sealant, and run cables through a weatherproof entry plate. Use a combiner box if running multiple panel pairs.
3. Install the charge controller. Mount it near the battery in a ventilated space. Connect battery cables first (with an inline fuse), then connect solar cables. Never connect solar to an MPPT controller without the battery connected.
4. Install the battery. Secure it with a battery box or tie-down straps rated for the weight. LiFePO4 batteries can be mounted in any orientation. Add a main battery disconnect switch.
5. Install the inverter. Mount it close to the battery with short, thick cables (2/0 AWG or larger for 2000W). Install an appropriate fuse between the battery and inverter. Wire the AC output to your RV's breaker panel or to dedicated outlets.
6. Wire the fuse box. Every positive wire in the system needs a fuse or breaker. Use a bus bar or fuse block to keep things organized and safe.
7. Test and commission. Verify all connections, check polarity, then enable the system. Monitor charge controller readings to confirm panels are producing expected power.

For detailed wiring diagrams and cable sizing, see our DIY solar hub which covers each component in depth.

Roof-Mount vs Portable Panels

Both approaches work, and many RVers end up using a combination.

Our recommendation: mount 200-400W on the roof for always-on baseline charging, and carry a portable 100-200W panel for boosting production when parked in shade. The roof panels keep the fridge running while you drive, and the portable panel lets you chase the sun at camp.

Alternator Charging Integration

Your RV's alternator produces far more power than solar panels, typically 1000-3000W depending on the vehicle. A battery-to-battery (B2B) charger like the Renogy DCC50S or Victron Orion-Tr Smart lets you charge your house battery from the alternator while driving.

A 30A B2B charger on a 12V system pushes about 360W into your house battery. On a 4-hour drive, that is 1440Wh of free charging. This is especially valuable on cloudy days or when your solar panels are shaded by trees.

Important: do not simply connect your LiFePO4 house battery directly to the alternator. LiFePO4 batteries have very low internal resistance and will pull too much current, potentially overheating and damaging your alternator. A proper B2B charger regulates the current and provides the correct charge profile.

Shore Power Charger Integration

When you are at a campground with hookups, you want to charge your battery bank quickly. A dedicated AC-to-DC charger (like the Progressive Dynamics PD9160AV or a LiFePO4-compatible converter) replaces or supplements your RV's existing converter.

Most factory RV converters output a float voltage designed for lead acid batteries (13.6V). LiFePO4 batteries need a bulk charge of 14.2-14.6V and no float stage. Either replace the converter or add a standalone LiFePO4 charger wired to your battery bank.

Some inverter/chargers combine both functions: they invert DC to AC when off-grid, and charge the battery when shore power is connected. This simplifies wiring but adds cost. Check our best power solutions for RV guide for all-in-one options.

Budget Breakdown

A solid RV solar system costs $1200-1800 for components. Here is a typical breakdown for the recommended system:

For a detailed cost analysis of DIY solar systems at various sizes, see our DIY solar system cost breakdown.

12V Batteries for RV Solar

These 12V LiFePO4 batteries from our database are 100Ah or larger, making them suitable for RV solar systems. Larger amp-hour ratings mean more days of autonomy between charges. Read our best LiFePO4 battery guide for detailed comparisons.

We are still building our database. Browse the full 12V battery listing to see all available options.

12V Inverters for RV Solar

These 12V inverters are suitable for RV installations. Look for pure sine wave output, low idle draw, and enough continuous watts for your largest AC load.