Solar Panel Size Calculator for Van Builds

Quick Answer

Van builds running a laptop, fan, lights, and hotspot router typically need 500W of rooftop solar and a 450Ah LiFePO4 battery. That covers 1.6 kWh/day with 2 days of reserve. The EcoFlow River 2 Pro handles the full van-life load with room to spare. For a roof-mounted DIY system, 3 Renogy 200W flexible panels and a 30A MPPT controller is the most common van build configuration.

Pre-Calculated System Specs

Based on 5.5 peak sun hours, 2-day autonomy, and typical Van Build loads.

ComponentMinimum SizeNotes
Daily Load1.6 kWhRaw before system losses
Adjusted Load1.9 kWh+20% system loss buffer
Solar Panels500W3x 200W or 2x 400W panels
Battery450Ah at 12VLiFePO4, 2-day autonomy (4.8 kWh total)
Charge Controller60A MPPTNEC 1.25x safety factor applied
Inverter500W continuous500W surge capacity, pure sine wave

Want to adjust for your exact appliances? Customize these numbers with our solar calculator

Recommended Turnkey Solution

EcoFlow River 2 Pro

768Wh capacity, 800W AC output — runs a fridge, lights, and electronics for 1–2 days.

768Wh

Capacity

800W

AC Output

220W

Max Solar In

Buy on EcoFlow.comView Solar Bundle

DIY Component Approach

Prefer to build a custom system? Use these components matched to the calculated specs above. A DIY build typically costs 20-35% less than a turnkey power station for the same energy capacity.

Solar Panels

500W total (3x 200W panels recommended)

Renogy 200W 12V Monocrystalline on Amazon

Battery

450Ah at 12V LiFePO4

LiTime 12V 200Ah LiFePO4 on Amazon

Charge Controller

60A MPPT minimum

Renogy 40A MPPT Rover on Amazon

Inverter

500W pure sine wave

Renogy 2000W Pure Sine Wave Inverter on Amazon

Van Build Solar System Guide

Van solar systems are constrained in two ways that RV and cabin systems are not: roof space and weight. A Ford Transit roof holds 400–500W of rigid panels comfortably. A Ram Promaster, with its wider roof, accommodates 600W. Weight matters because every pound of panels and battery reduces payload and affects handling. This is why van builders prefer LiFePO4 batteries (half the weight of equivalent AGM) and why monocrystalline panels — more efficient per square inch — are preferred over polycrystalline.

Wiring a van solar system requires more planning than a cabin or shed install because everything is in a confined moving space with vibration loads on connections. Use marine-grade tinned copper wire, ring terminals with heat shrink, and DIN rail fusing. A Victron SmartShunt is worth the $75 for accurate battery state-of-charge monitoring — you want to know if you have 30% or 80% left before committing to a remote campsite. A Victron BlueSolar or Renogy Wanderer MPPT controller pairs well with a Victron SmartShunt for Bluetooth monitoring.

The alternator-to-battery charger is a frequently overlooked piece of van solar. While driving, the van's alternator can charge the house battery faster than the solar array. A DC-to-DC charger like the Renogy DCC30S isolates the house and start batteries properly while charging at a controlled 30 amps — better than a simple isolator relay that can flatten your start battery if your house bank is deeply discharged.

Frequently Asked Questions

How much solar does a van need?▼
A van build for remote work with a laptop, LED lights, fan, phone, and hotspot router uses about 1,200–1,400Wh per day. With 5.5 peak sun hours, that requires 300–340W of panels. Most van builders install 200–400W on the roof. Two 200W panels on a Promaster or Transit roof fit cleanly. The Renogy 200W Rigid Monocrystalline is the most popular van roof panel. Pair with a 100–200Ah LiFePO4 battery and a 30–40A MPPT controller.
What battery size is best for a van?▼
100Ah LiFePO4 at 12V is the minimum for a comfortable van build — it stores 1,200Wh of usable energy. For remote work with full-day laptop use, upgrade to 200Ah (2,400Wh usable). A 200Ah LiFePO4 combined with 300W of solar runs a full work day plus evening lighting and fan use without depleting the battery below 30%. The LiTime 100Ah and Renogy 100Ah Smart Lithium are both excellent choices at under $300.
Is 200W of solar enough for a van?▼
200W handles a minimalist van setup: laptop 4 hours, LED lights 4 hours, phone charging, and fan use. Daily output in a 5-sun-hour region is 800Wh, which covers about 800–900Wh of van loads. If you work 8 hours on a laptop daily, add a second 100W panel. The breakeven for 200W is roughly: no fridge, limited laptop use, no high-draw appliances. Most full-time van lifers end up upgrading to 300–400W within the first year.
Should I use flexible or rigid solar panels on my van?▼
Rigid monocrystalline panels produce more power, last longer, and cost less per watt than flexible panels. The main advantage of flexible panels is that they can be mounted on curved surfaces and weigh less. For a flat van roof, rigid panels are the better long-term investment. If your van roof has a significant crown or curve, BougeRV's flexible 200W panels are the practical choice. Avoid flexible panels rated under 20% efficiency — cheap flexible panels degrade significantly faster in the UV exposure of daily outdoor use.

Need a custom calculation?

The numbers above use typical van build defaults. Adjust for your exact appliances and location.

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