How to Wire a Van Solar System (Step-by-Step Diagram)
By Frank Zale · August 7, 2026 · 3 min read
A van solar wiring diagram looks intimidating, but the power path is actually simple and always the same: solar panels → charge controller → battery → fuse block → your 12V loads, with an inverter tapped off the battery for AC. Get that order right, fuse every source, and you have a safe system. Here's the whole thing, step by step.
The core power path
| Stage | What connects | Why |
|---|---|---|
| 1. Panels | Roof panels → roof gland → MPPT | Collect sunlight |
| 2. Charge controller | MPPT → battery | Regulates charging safely |
| 3. Battery | The heart of the system | Stores energy |
| 4. Bus bars / fuse block | Battery → distribution | One clean split point |
| 5. DC loads | Fuse block → fridge, fan, lights | Your 12V appliances |
| 6. Inverter | Battery → inverter → AC outlets | Only for AC appliances |
Every cable that touches the battery gets a fuse close to the battery. That single rule keeps a van from catching fire.
Step by step
- Panels to controller. Run panel cable through a weatherproof roof gland to the MPPT input, with a fuse or breaker on the line. Series or parallel is your choice — see series vs parallel.
- Controller to battery. Short, thick, fused cable from the MPPT output to the battery.
- Alternator (optional). A DC-DC charger links the starter battery to the house battery so driving charges you too.
- Battery to bus bars. Run the main positive through a main fuse to a distribution point (bus bar or fuse block) — everything branches from here.
- DC loads. Each appliance gets its own correctly-sized fuse. Sizing is in the wire & fuse guide.
- Inverter. Wire the inverter straight to the battery with a big fuse and thick cable — it pulls the most current of anything in the van.
The two cables that matter most
The battery-to-inverter and battery-to-bus-bar cables carry the most current. Undersize either and you get voltage drop, heat, and fire risk. Use the wire gauge calculator for these — don't guess.
Ground properly
Connect the negative bus bar to the chassis at one clean, bare-metal point. A single solid ground avoids odd faults and is standard practice.
Don't want to design it by hand?
The free calculator takes your appliance list and outputs the whole system — panel size, controller, battery, and the exact wire gauges and fuse ratings for each run.
FAQ
What order do van solar components connect in?
Panels → charge controller → battery → fuse block → 12V loads, with the inverter wired directly to the battery. Every connection to the battery gets a fuse.
Do I connect solar panels straight to the battery?
Never. Panels must go through a charge controller, which regulates voltage and prevents overcharging. Connecting them directly will damage the battery.
Where do the fuses go in a van solar system?
As close as possible to the battery on every cable that leaves it, and one per DC appliance at the fuse block.