RV Solar Panel Calculator
Size a solar panel system for your RV or campervan. Calculate daily energy needs, panel wattage, charge controller size, and wire gauge.
System Settings
RV Appliances
| Appliance | Watts | Hours/Day | Wh/Day | |
|---|---|---|---|---|
| 120 | ||||
| 45 | ||||
| 260 | ||||
| 1200 | ||||
| 30 | ||||
| 320 | ||||
| 180 | ||||
| Total | 2155 Wh |
Battery Analysis
How It Works
This calculator helps you size a complete solar system for your RV, campervan, or off-grid vehicle. Here is how it works:
- Add your appliances — enter each device with its wattage and average daily hours of use. The calculator comes pre-loaded with common RV appliances.
- Total daily Wh — we sum watts x hours for every appliance to get your daily energy consumption in watt-hours.
- Panel wattage — daily Wh is divided by your average sun hours and an 85% system efficiency factor to determine how many watts of solar panels you need.
- Charge controller — total panel wattage is divided by battery voltage and multiplied by 1.25 (safety margin), then rounded up to the nearest standard controller size.
- Wire gauge — based on the calculated amperage, we recommend an appropriate wire gauge to minimize voltage drop and ensure safe operation.
Frequently Asked Questions
How many solar panels do I need for my RV?
It depends on your daily energy consumption. A typical RV using basic appliances (lights, fridge, phone charging) needs 200-400W of solar panels. Add up the watt-hours for each appliance you use daily, then divide by your average peak sun hours and a 0.85 efficiency factor to get the recommended panel wattage.
What size charge controller do I need for RV solar?
Your charge controller must handle the maximum current from your panels. Divide total panel wattage by battery voltage, then multiply by 1.25 for a safety margin. For example, 400W of panels on a 12V system needs at least a 42A controller — so you would round up to a 50A MPPT controller.
Can I run an air conditioner on RV solar?
Running a rooftop RV AC unit (1,200-1,500W) on solar alone is very challenging. You would need at least 2,000-3,000W of panels and a large lithium battery bank (400Ah+). Most RV solar setups are designed for lights, fans, fridges, and electronics rather than high-draw appliances like AC.
Should I use a PWM or MPPT charge controller for my RV?
MPPT (Maximum Power Point Tracking) controllers are strongly recommended for RV solar. They are 20-30% more efficient than PWM controllers, especially when panel voltage is higher than battery voltage. The higher upfront cost is quickly offset by increased energy harvest.