Most overlanders need between 200W and 400W of solar panels.
A basic setup — phone charging, lights, and a fan — can run on 200W. If you’re running a fridge, laptop, and multiple devices, plan for 400W or more. Not sure where you fall? Add up what you’re powering and how long you use it each day. We’ll show you exactly how below.
What Uses Power While Overlanding?
Before you pick a solar setup, you need to know what’s draining your battery. Here are the most common devices overlanders use:
| Device | Typical Watts |
|---|---|
| LED interior lights | 10W |
| Portable fridge/cooler | 40–60W |
| Phone charger | 10–20W |
| Laptop | 45–100W |
| Water pump | 30–50W |
| Fan | 20–50W |
| Portable AC unit | 300–600W |
Tip: Check the label on each device for its exact watt rating. This makes your estimate much more accurate.
How Solar Panels Work (The Short Version)
Solar panels turn sunlight into electricity. That’s really all you need to know to get started.
For overlanding, two types are worth knowing about:
- Monocrystalline — More efficient. Better if you have limited roof space. Costs a bit more.
- Polycrystalline — Slightly less efficient. Cheaper. Still works great for most setups.
Either type will do the job. Most overlanders go with monocrystalline because roof space on a vehicle is limited and you want to get the most power out of every panel you mount.
How to Calculate Your Solar Needs
Step 1: List Your Devices
Write down every device you plan to use. Next to each one, note the watt rating. You can find this on the device label or in the manual.
Step 2: Multiply Watts × Hours Per Day
For each device, multiply its watt rating by how many hours you use it each day. This gives you watt-hours (Wh) — the standard way to measure daily energy use.
Here’s an example:
| Device | Watts | Hours/Day | Daily Wh |
|---|---|---|---|
| LED interior light | 10W | 4 hrs | 40 Wh |
| Portable fridge | 50W | 24 hrs | 1,200 Wh |
| Phone/laptop charger | 60W | 6 hrs | 360 Wh |
| Water pump | 40W | 1 hr | 40 Wh |
| Total | 1,640 Wh |
Step 3: Add a 30% Safety Buffer
Solar panels don’t always run at full power. Clouds, shade, and the angle of the sun all reduce output. Add 30% to your total to cover these situations.
1,640 Wh × 1.3 = 2,132 Wh per day
Step 4: Divide by Your Daily Sun Hours
Solar panels only produce full power during peak sunlight hours. In most of the US, that’s about 4 to 6 hours per day, depending on location and season.
Divide your daily watt-hours by your expected sun hours to get the solar wattage you need:
2,132 Wh ÷ 5 sun hours = ~426W of solar
So for this example, a 400W to 500W solar setup would cover your daily needs.
Choosing a Solar System
Once you know how much power you need, you have to pick the right gear. Every overlanding solar setup has three main parts:
- Solar panels — collect energy from the sun
- Charge controller — protects your batteries from overcharging
- Battery bank — stores the power for later use
A 100W solar panel produces about 30 amp-hours per day. Most overlanders need at least 200W–400W of panels to cover daily use.
Tip: Use a solar calculator to get a fast estimate based on your specific devices.
Battery Selection
Your battery stores the power your panels collect. Choosing the right one matters a lot.
Here’s a quick comparison of the three most common types:
| Battery Type | Cost | Weight | Maintenance | Best For |
|---|---|---|---|---|
| Lead Acid | Low | Heavy | Yes | Budget builds |
| AGM | Medium | Medium | No | Mid-range builds |
| Lithium-Ion | High | Light | No | Best overall |
Lithium-ion batteries are the top pick for most overlanders. They’re lighter, last longer, and give you more usable power than the other options. Yes, they cost more upfront — but they’re worth it for serious off-grid travel.
How Much Battery Capacity Do You Need?
Take your daily watt-hour total from the calculation above and match it to your battery capacity. Most overlanders run on a 12V system, so make sure your batteries and panels are compatible.
Brands like Renogy offer solar panels and battery banks that work well together right out of the box.
Installation Considerations
Where and how you mount your panels makes a big difference. Here are the key things to think about:
Vehicle Type
- Trucks and SUVs — roof racks are the most common mounting spot
- Vans — roof mounts work great and keep panels out of the way
- Trailers — more roof space means you can run more panels
Available Roof Space
More roof space = more panels = more power. If space is tight, go with monocrystalline panels since they produce more power per square foot.
Your Location
More sun = more power. If you’re traveling through the Southwest US, you’ll get more out of your panels than someone camping in the Pacific Northwest in fall.
Your Budget
| Setup Size | Estimated Cost | Best For |
|---|---|---|
| 200W starter kit | $300–$600 | Light users |
| 400W mid-range | $600–$1,200 | Most overlanders |
| 600W+ full build | $1,200+ | Heavy users, long trips |
Don’t Forget Your Vehicle’s Electrical System
Your solar setup needs to work alongside your vehicle’s battery and alternator. Adding fuses to your system protects everything from electrical problems.
Monitoring and Maintenance
Once your system is installed, keep it running well with these basics:
Key Components to Know
- Charge controller — regulates power flow from panels to batteries. A PWM (Pulse Width Modulation) controller is the most common type and works well for most setups
- Fuse box — protects your system from power surges and short circuits
- Battery monitor — shows your battery charge level in real time so you know how much power you have left
Simple Maintenance Tips
- Clean your panels regularly — dust and dirt can cut output by 20% or more
- Check your connections every few trips for corrosion or loose wires
- Watch your battery monitor — don’t let your battery drop below 20% charge (50% for lead acid)
Portable and Alternative Charging Options
Not ready for a full roof-mounted system? Portable options work great for lighter use.
Portable Solar Panels
Foldable panels can be set up anywhere and packed away when you’re done. They’re perfect for:
- Weekend trips
- Smaller vehicles with limited roof space
- Supplementing a fixed panel setup
Portable Power Stations
These are all-in-one units with a built-in battery and outlets. Just charge them up with solar panels or at home before you leave. Great for phone charging, lights, and small devices.
Dual Battery Setup
Many overlanders add a second battery to their vehicle. This lets you run devices without draining your starter battery. Pair it with solar panels and a charge controller for the best results.
Electrical System Components: Quick Reference
Here’s a cheat sheet of the main parts in any overlanding solar setup:
| Component | What It Does |
|---|---|
| Solar panels | Collect energy from sunlight |
| Charge controller | Prevents battery overcharging |
| Battery bank | Stores power for later |
| Inverter | Converts DC power to AC for household devices |
| Fuse box | Protects the system from surges |
| Battery monitor | Shows real-time charge level |
| Wiring | Connects everything together |
Wire gauge matters. Thicker wire (lower gauge number) carries more power with less heat. Using the wrong gauge can cause energy loss or even a fire. When in doubt, go thicker.
Frequently Asked Questions
What size solar panel is best for overlanding?
Most overlanders do well with 200W to 400W of solar. If you’re just charging phones and running lights, 200W is enough. Add a fridge or laptop and you’ll want 400W or more.
How much solar do I need for an off-road trailer?
It depends on what you’re running. Use the calculation from earlier in this guide — add up your device watts, multiply by hours used, add 30%, then divide by your daily sun hours. That gives you your target wattage.
Is a 100W solar panel enough for camping?
It can be — if you’re keeping it simple. A 100W panel works fine for phone charging and LED lights. Add a fridge or laptop and you’ll likely need more.
How do I know how much solar I need to charge my battery?
Take your battery’s total capacity in watt-hours and divide by your daily sun hours. That tells you the minimum panel size needed to fully recharge it in one day.
What’s the difference between PWM and MPPT charge controllers?
- MPPT — more efficient, better for larger systems or low-light conditions
- PWM — cheaper, works well for smaller systems
For most overlanding setups under 400W, PWM works fine. Go with MPPT if you’re running 400W or more.