Planning an off-grid van build? The electrical system is the single most important — and most misunderstood — component of any camper van conversion. Get it right, and you’ll have reliable power for everything from your fridge to your laptop, whether you’re parked at a Florida state park or boondocking in the mountains of North Carolina. Get it wrong, and you’re looking at dead batteries, fried components, and a very expensive headache.
At Beachside Custom Vans in Jacksonville, Florida, we’ve designed and installed hundreds of van electrical systems. In this guide, we’re breaking down everything you need to know about building a proper off-grid electrical system for your van — from lithium batteries and solar panels to inverters, shore power, and the components that tie it all together.
Let’s get into it.
What Does “Off-Grid” Actually Mean for a Van Build?
When we say “off-grid van build,” we’re talking about a camper van that can operate independently from external power sources for extended periods. That means:
- Running your lights, USB outlets, fridge, and fan without plugging in
- Charging your batteries through solar panels and your vehicle’s alternator
- Having the option to connect to shore power (campground hookups) when available
- Powering 120V appliances like a microwave, coffee maker, or induction cooktop through an inverter
The goal isn’t to never plug in — it’s to not need to. A well-designed off-grid electrical system gives you the freedom to camp anywhere without worrying about power.
The Core Components of a Van Electrical System
Every van electrical system has the same basic building blocks. Here’s what goes into a professional off-grid setup:
1. Lithium Batteries (LiFePO4)
Lithium iron phosphate (LiFePO4) batteries are the gold standard for van builds in 2026. Here’s why we use them exclusively at Beachside Custom Vans:
- 3-5x longer lifespan than AGM or lead-acid batteries (2,000-5,000 cycles vs. 300-500)
- 50% lighter than equivalent lead-acid batteries
- Can be discharged to 80-100% of capacity (lead-acid should only go to 50%)
- Built-in Battery Management System (BMS) for safety
- Faster charging and more efficient energy use
For most van builds, we recommend 200Ah to 400Ah of lithium battery capacity at 12V. A couple heading out on weekend trips might be fine with 200Ah. A full-time van lifer running an induction cooktop and residential fridge will want 400Ah or more.
We install Victron Smart Lithium batteries and Battle Born batteries, depending on the build and budget. Both are proven, reliable options with solid warranties.
2. Solar Panels
Solar is your primary charging source when you’re off-grid. Panels mounted on your van’s roof convert sunlight into electricity that charges your battery bank.
For most Sprinter, Transit, and ProMaster builds, we install between 200W and 600W of rooftop solar. Here’s a general sizing guide:
- 200W: Light use — phone charging, LED lights, vent fan
- 400W: Moderate use — fridge, lights, devices, occasional inverter use
- 600W+: Heavy use — full-time living, induction cooking, residential fridge, multiple devices
We use rigid monocrystalline panels for most builds because they’re durable, efficient, and handle Florida’s heat well. Flexible panels look sleek but tend to degrade faster, especially in hot climates.
Pro tip: Solar panel output is rated under ideal lab conditions. In real-world use — especially in Florida where heat reduces efficiency — expect about 70-80% of rated output on a good day.
3. Solar Charge Controller (MPPT)
The charge controller sits between your solar panels and your batteries. It regulates the voltage and current coming from the panels to safely and efficiently charge your batteries.
We exclusively use MPPT (Maximum Power Point Tracking) controllers — specifically Victron SmartSolar MPPT controllers. MPPT controllers are 20-30% more efficient than cheaper PWM controllers, which means more usable power from the same solar panels.
The Victron SmartSolar line connects to the Victron app via Bluetooth, so you can monitor your solar production, battery state, and charging history right from your phone.
4. Inverter / Inverter-Charger
An inverter converts your 12V DC battery power into 120V AC power — the same electricity that comes out of your wall outlets at home. This is what lets you run a coffee maker, charge a laptop, use a blender, or power a microwave in your van.
For most builds, we install a Victron MultiPlus inverter-charger. The “charger” part means it also works in reverse: when you’re plugged into shore power at a campground, it charges your batteries and passes AC power through to your outlets.
Common inverter sizes for van builds:
- 1,000W: Basic needs — laptop, phone charger, small appliances
- 2,000W: Most popular — can handle a microwave, coffee maker, hair dryer (one at a time)
- 3,000W: Power user — induction cooktop, multiple appliances simultaneously
We size the inverter based on what you actually plan to run. Bigger isn’t always better — a larger inverter draws more power just sitting idle.
5. DC-DC Charger (Alternator Charging)
This is the unsung hero of van electrical systems. A DC-DC charger takes power from your vehicle’s alternator (which charges your starter battery while you drive) and uses it to safely charge your house batteries.
This means every time you drive, you’re charging your battery bank. On a long driving day, a good DC-DC charger can put 30-50 amps into your batteries — that’s a significant chunk of your daily power needs.
We install Victron Orion-Tr Smart DC-DC chargers, which are specifically designed for lithium batteries and modern vehicles with smart alternators.
6. Shore Power Inlet
Even on an off-grid build, having a shore power connection is smart. It lets you plug into 30A campground power when available, which charges your batteries and powers your AC outlets simultaneously.
We install weatherproof 30A shore power inlets on the exterior of the van, wired through the Victron MultiPlus inverter-charger. Plug in, and the system automatically switches from inverter mode to pass-through charging.
7. Fuse Box, Bus Bars, and Wiring
This is where professional installation really matters. Your electrical system is only as good as its wiring. We use:
- Blue Sea Systems fuse boxes and bus bars
- Marine-grade tinned copper wiring
- Properly sized fuses and breakers for every circuit
- Heat shrink connectors and cable management throughout
Cheap wiring and poor connections are the #1 cause of electrical fires in DIY van builds. This isn’t where you cut corners.
The Victron Ecosystem: Why We Build Around It
You’ve probably noticed we mention Victron a lot. That’s intentional. At Beachside Custom Vans, we build almost every electrical system around Victron components, and here’s why:
Victron Connect App & GX Monitoring
Every Victron component connects via Bluetooth to the VictronConnect app. But the real power move is adding a Victron Cerbo GX — a central monitoring hub that ties your entire electrical system together.
With the Cerbo GX and a GX Touch display (or the VRM online portal), you can see:
- Real-time battery state of charge, voltage, and current
- Solar production and history
- Shore power status
- Inverter load
- Historical data and trends
It’s like having a dashboard for your entire electrical system. Our clients love it because it takes the guesswork out of power management.
Reliability and Support
Victron is a Dutch company that’s been building power electronics since 1975. Their products are used in marine, off-grid, and industrial applications worldwide. When we install Victron, we know it’s going to work — and if something ever does go wrong, their support and warranty are excellent.
How Much Does an Off-Grid Electrical System Cost?
Let’s talk real numbers. At Beachside Custom Vans, our electrical system installations typically fall into three tiers:
Basic Off-Grid Package ($4,000 – $6,000)
- 200Ah lithium battery
- 200W solar
- MPPT charge controller
- DC-DC charger
- Basic 12V distribution (lights, USB, fan, fridge)
- Shore power inlet
Mid-Range Off-Grid Package ($7,000 – $10,000)
- 300Ah lithium battery bank
- 400W solar
- MPPT charge controller
- DC-DC charger
- 2,000W inverter-charger
- Full 12V + 120V distribution
- Shore power inlet
- Victron monitoring
Full Off-Grid Package ($11,000 – $15,000+)
- 400Ah+ lithium battery bank
- 600W solar
- MPPT charge controller
- DC-DC charger
- 3,000W inverter-charger
- Complete 12V + 120V distribution
- Shore power inlet
- Cerbo GX + GX Touch monitoring
- Induction cooktop circuit
These prices include parts and professional installation. Every build is different, so these are ranges — your specific needs may push the price up or down.
DIY vs. Professional Installation: An Honest Take
We get it — YouTube makes it look easy. And honestly, a handy person with electrical knowledge can build a functional system. But here’s what we see regularly from DIY electrical jobs that come into our shop:
- Undersized wiring that overheats under load
- Missing or incorrect fuse protection
- Poor connections that corrode and fail
- Incompatible components that don’t communicate properly
- No proper grounding
- Lithium batteries without correctly configured charging profiles
An electrical system is the one part of a van build where mistakes can be dangerous. We’ve repaired and rebuilt dozens of DIY electrical systems, and in many cases, the owner ends up spending more on the fix than a professional install would have cost in the first place.
If you’re going to DIY, at minimum: use a proper wiring diagram, size your wires correctly, fuse everything, and don’t mix component brands without understanding compatibility.
Common Electrical Questions We Get
“Can I run an AC unit off my battery bank?”
Technically yes, but it’s impractical for most builds. A rooftop AC unit draws 1,000-1,500W continuously. Even with a 400Ah battery bank, you’d drain it in 3-4 hours. We recommend a MaxxAir fan for ventilation and AC only when connected to shore power.
“How long will my batteries last without charging?”
With a 300Ah lithium bank and moderate use (fridge, lights, devices, fan), most of our clients get 2-3 days of comfortable use without any charging. Add a couple hours of driving or a sunny day, and you can go indefinitely.
“Do I need solar if I drive every day?”
Solar isn’t strictly necessary if you drive daily — your DC-DC charger will handle most of your charging needs. But solar gives you the freedom to park for multiple days without moving. For most people, the peace of mind is worth it.
Ready to Build Your Off-Grid Electrical System?
Whether you’re planning a full van conversion or just want to add a proper electrical system to your existing van, we can help. At Beachside Custom Vans, we design and install electrical systems as standalone projects — you don’t need a full build to get professional-grade power in your van.
We’re located in Atlantic Beach, just outside Jacksonville, Florida. Stop by the shop, give us a call, or fill out our contact form to get started on your off-grid van build.