Camper Van Solar Kit — Size It Right & Get the Wiring Diagram

Thin wire is how van fires start.

A cable that’s too thin overheats — and you sleep in the thing you built. Wattonomy sizes every conductor to carry its fuse and holds voltage-drop in check, then shows you the math. Oversize it and you waste hundreds; undersize it and it’s a fire risk. Sized right — to standard.

A van system in four numbers.

Four numbers that have to agree. Get one wrong and you run out at 2am — or overspend by hundreds.

Daily energy

Fridge, lights, devices, fan, Starlink — we add up real Wh/day from your appliances, not a sticker rating.

Battery

100–400Ah LiFePO4 at 12V, sized to your days of backup and the cold-weather capacity hit.

Solar + charging

Roof watts plus DC-DC (charge while you drive) and shore power, balanced to your climate.

Cables & fuses

Every gauge, fuse rating and AIC matched to the load and your real cable run lengths.

What you walk away with — free

A validated system sized to your appliances — not a template
A clean wiring diagram with every cable gauge and fuse spelled out
Cable & fuse sizing with the voltage-drop checked for your run lengths
A shoppable parts list, each line traceable to ABYC or Victron specs

Building it for real? Unlock the build binder.

Free gets you a safe, correctly-sized design. The build binder gets you the documents to build it right — and prove it's right.

Printable wiring diagram, yours to keep & tape inside the van

Full parts list, every line sourced

The volt-drop & fusing calculation trail — the "why" behind every spec

Save your build & compare options side by side

Start your design — free

The build binder is a one-time unlock — no subscription, no auto-renew.

Questions

Do I need an account?

No. Design your whole system free, no email required. You only create an account if you want to save builds or unlock the printable build binder.

Will it tell me the right wire gauge and fuse?

Yes — every conductor is sized to carry its fuse and stay within a 3% voltage drop, with the gauge, fuse rating and AIC shown and sized to ABYC E-11.

Can I add my own appliances?

Yes. Add any custom load with its watts and hours, and it feeds straight into the sizing.

Is this just trying to sell me a kit?

No. The parts list is vendor-neutral and standards-referenced — buy the components anywhere. We make the design, not the markup.

The standards we build to

Plain version: these are the recognized rulebooks your design is sized against, so the numbers hold up to a surveyor, an inspector or an insurer.

ABYC E-11The US standard for AC & DC wiring on boats — what a surveyor or insurer actually checks.
Victron datasheetsReal component specs — fuse classes, charge limits, MPPT ratings — not generic assumptions.

Wattonomy applies these standards in its calculations. It is not certified, sponsored or endorsed by ABYC, ISO, NFPA or Victron — it sizes your design to meet what they require, and shows the working.

Design my van system

It takes about a minute. No account, no email.

Camper van solar, sized right the first time.