RV SOLAR
SIZING GUIDE

STEP 1: CALCULATE DAILY POWER USAGE

List every device, estimate hours per day, multiply watts by hours for watt-hours (Wh):

• LED Lights (5 bulbs): 50W x 5 hrs = 250 Wh
• 12V Fridge: 50W x 12 hrs = 600 Wh
• Phone Charging (2): 20W x 3 hrs = 60 Wh
• Laptop: 60W x 4 hrs = 240 Wh
• Roof Fan: 30W x 8 hrs = 240 Wh
• Water Pump: 60W x 0.5 hrs = 30 Wh
• TV/Streaming: 60W x 3 hrs = 180 Wh

Example total: ~1,600 Wh/day

STEP 2: ACCOUNT FOR LOSSES

You get roughly 5-6 peak sun hours per day in most of the U.S. Factor in 20-25% loss for heat, wiring, and weather.

Formula: Daily Wh / peak sun hours / 0.75 = watts needed

Example: 1,600 / 5 / 0.75 = ~427W of panels

STEP 3: MATCH YOUR RV TYPE

Pop-Up Camper / Teardrop

100-200W. Limited roof space — consider a portable ground panel.

Travel Trailer / Small Fifth Wheel

200-400W. Good roof space for 2-4 rigid panels.

Class C Motorhome

300-600W. Sufficient roof for a full array.

Class A / Large Fifth Wheel

600-1200W+. Full-time living with plenty of roof space.

STEP 4: SIZE YOUR BATTERY BANK

Store at least 1.5-2x your daily usage. For 1,600 Wh: need ~200Ah at 12V (one or two 100Ah LiFePO4 batteries).

STEP 5: CHOOSE YOUR CONTROLLER

Divide total wattage by battery voltage: 427W / 12V = ~36A. A 40A MPPT controller fits. See our controller guide.

QUICK REFERENCE

READY TO BUY?

Now that you know your target wattage: