Installing Solar on Your Van: A Practical Setup Guide

Solar panels are the primary charging source for most van builds when you're parked. They're silent, maintenance-free, and convert sunlight directly into battery charge. Getting the sizing and installation right means the difference between comfortably running all your devices and constantly worrying about battery levels.

We install solar systems on every build at our San Diego shop. This guide covers the same fundamentals we follow — from calculating your power needs to testing the finished system.

Should I Use Rigid or Flexible Solar Panels on My Van?

Two main options for van roofs: rigid and flexible.

Rigid Panels

• Higher efficiency (18–22%)
• 25+ year lifespan
• Air gap between panel and roof improves cooling and performance
• More durable — tempered glass top, aluminum frame
• Heavier and taller profile

Flexible Panels

• Lower efficiency (15–18%)
• 5–10 year lifespan
• Flat against the roof — no air gap means they run hotter and degrade faster
• Lighter and lower profile
• Easier to damage

We recommend rigid panels for most builds. The efficiency gain, longevity, and cooling advantage from the mounting gap make them the better long-term investment. Flexible panels make sense if you need an extremely low profile (stealth builds) or can't handle the extra weight.

How Do I Mount Solar Panels on a Van Roof?

For rigid panels, use Z-brackets or L-brackets bolted to the roof. Drill pilot holes, apply Dicor self-leveling lap sealant generously around the bolt holes, and torque the bolts down. More sealant is better than less — you're creating a waterproof seal that has to survive highway speeds and years of UV exposure.

Maintain a 1–2 inch gap between the panel bottom and the roof surface. This air gap allows cooling airflow under the panels, which improves efficiency. Solar panels lose output as they heat up — every degree above 25°C reduces output by roughly 0.3–0.5%.

If you have a roof rack, many rack systems have dedicated solar panel mounts that bolt directly to the rack rails. This avoids putting new holes in the roof.

How Do I Install an MPPT Charge Controller?

The charge controller regulates the power coming from the solar panels and delivers it to the battery bank at the correct voltage and current. Use an MPPT controller — it's 20–30% more efficient than PWM and converts excess voltage into additional charging amps.

Popular MPPT controllers for van builds include the Victron SmartSolar series and Renogy Rover series. Both have Bluetooth monitoring capability, which lets you check solar production and charging status from your phone.

Mount the controller in a ventilated spot — they generate heat during charging. Program it for your battery chemistry (lithium, AGM, or whatever you're running). Lithium charge profiles are different from lead-acid — wrong settings can damage batteries or leave them undercharged.

How Do I Test My Van Solar System?

With everything connected, check the charge controller display. You should see:

• Panel voltage (open circuit voltage or operating voltage depending on the mode)
• Charging current going to the batteries
• Battery voltage
• Charging state (bulk, absorption, float)

Test in full sun first to verify peak output. Then shade one panel to see how the system responds. If panels are in series, shading one will drop the entire string's output significantly — if that's a problem for your setup, consider parallel wiring or adding panel-level optimizers.

Monitor the system over a few days of normal use. You're looking for consistent charging that replenishes your daily usage. If batteries aren't getting back to full by the end of each sunny day, you may need more panel capacity. For more on the full electrical system, see our platform-specific guides.