Campervan Electrical System: The Complete Guide to Campervan Electrics

Updated: 23 September 2026 · EuroVan Shop

What is a campervan electrical system?

A campervan electrical system is a second, independent 12 V network that runs your living area without touching the starter battery. It stores energy in a leisure battery, refills it from up to three sources, and delivers it safely to your fridge, lights, water pump, fan and USB sockets, plus 230 V sockets if you add an inverter.

The vehicle's own starter battery stays in charge of starting the engine. The two networks are linked only through a charger, so running the fridge overnight can never leave you unable to start.

You can build this system part by part, or buy it as a matched set: EuroVan Shop's campervan electrical kits combine a LiFePO4 battery, genuine Victron chargers and the protection parts, pre-sized and supplied with a detailed wiring diagram.

What electrics do I need in a campervan?

You need a leisure battery, at least one way to charge it, a protected distribution to your 12 V appliances and, only if you use mains appliances, an inverter. Everything else is comfort.

Solar panels are not included: you choose them to fit your roof.

Three ways to charge a leisure battery: alternator, solar and hook-up

The most reliable campervan electrics combine all three sources, because each one covers the gaps of the others: driving days, sunny days and campsite nights.

• Alternator, via a DC/DC charger. The Victron Orion-Tr Smart 12/12-30A takes power from the starter battery side while the engine runs and delivers up to 30 A (40 A peak) to the leisure battery with a 3-stage charge. Engine-running detection means it never draws down the starter battery when you are parked. It replaces the older split charge relay; see our DC/DC charger vs split charge relay guide.
• Solar, via an MPPT controller. The Victron SmartSolar MPPT 100/30 accepts up to 440 W of panels on a 12 V system; in the VANPOWER kit it is specified for 300 to 500 W of panels. Read how many solar panels you need before choosing yours.
• Mains hook-up. Without an inverter, the Victron Blue Smart IP22 12V 15A charger recharges the battery from a 230 V socket. With an inverter, its built-in 20A charger does the job and the automatic bypass powers your 230 V appliances at the same time, with nothing to switch.

All three Victron chargers can be monitored over Bluetooth in the VictronConnect app.

Fuses, isolators and distribution: the safety layer

Every circuit that leaves the battery must be protected by a fuse and be able to be cut, and the protection belongs as close to the battery as possible. This layer is what keeps a short circuit from becoming a fire.

In the VANPOWER kit, the battery isolator switch (275 A continuous) is used three times: on the battery, solar and alternator circuits. Bus bars gather the positives and negatives in one place so each device has a clean, short connection. The terminal lugs and fuses pack contains MEGA fuses and resettable fuses, sized to the inverter power you choose.

We do not give cable sections or fuse ratings in this guide: they depend on the current and the cable length of your layout. They are given in the VANPOWER wiring diagram (with cable sections); for any other layout, have them sized by a qualified person. The circuit logic is explained step by step in our 12V campervan wiring diagram guide.

Do you need an inverter in a campervan?

Only if you use 230 V appliances such as a coffee machine, microwave or kettle. A 12 V compressor fridge, LED lights, a roof fan and USB charging run directly on 12 V, which is more efficient.

To size an inverter, read the wattage on your most power-hungry appliance and multiply it by 1.25 to 1.5: an 800 W appliance needs a 1000 to 1200 W inverter. Keep in mind the current it pulls from the battery: roughly the appliance wattage divided by 12, plus conversion losses, so a 1000 W load draws in the region of 85 A or more (estimate). That is why the 1500 W and 2000 W options are recommended with the 314 Ah battery.

• No inverter: fridge, USB and 12 V; you can add one later.
• 600 W: laptop and small appliances.
• 1000 W: one small appliance such as a mini-oven or microwave.
• 1500 W: one powerful appliance such as a kettle (about 1200 W).
• 2000 W: several appliances at once.

More detail in what size inverter for a campervan. Any 230 V installation should be checked by a qualified electrician.

How big a leisure battery do you need? 100, 200 or 314 Ah

Choose 100 Ah for weekends, 200 Ah for several days off-grid and 314 Ah for full-time van life or a powerful inverter. To compare, convert amp-hours into watt-hours: Wh = 12.8 V × Ah. A LiFePO4 battery lets you use most of that energy (the VANPOWER sheet quotes 95%).

As a real load, a VANCOOL 50 L compressor fridge draws 25 to 30 W in use, roughly 50 to 60 Ah over a full day. The runtimes below are estimates for that fridge alone, with no charging at all.

In practice, solar and driving top the battery up every day, so real autonomy is longer. See how long a 12V fridge runs on a leisure battery and LiFePO4 vs AGM.

12V or 24V: which is better for a campervan?

For a campervan, 12 V is the practical choice: the vehicle, the DC/DC charger and most van appliances already work on 12 V, and the VANPOWER kit is a 12 V system. A 24 V system halves the current for the same power, which mainly helps very large installations.

A 24 V battery does not last longer by itself: what counts is the stored energy in watt-hours. A 12.8 V 200 Ah battery and a 25.6 V 100 Ah battery hold the same energy.

Kit, individual components or a portable power station?

A complete kit is the simplest route for a fixed installation, individual components suit builders who already own part of the system, and a portable power station suits people who do not want to install anything.

Every VANPOWER component is also sold separately, so you can complete an existing system. Not sure? Our team can build a custom kit: contact us.

What is in the VANPOWER campervan electrics kit?

The VANPOWER kit contains everything between the solar panels and your appliances, pre-sized to the battery and inverter you choose.

The components are ECE R10 certified. For conversion approval, check your national rules (DVLA/VCA, TÜV, RDW).

Configure the VANPOWER kit

VANPOWER or VANPOWER SMART: which kit should you choose?

Both kits share the same battery, Victron chargers, inverter options and wiring diagram; the only difference is how you switch your 12 V circuits.

Choose VANPOWER for classic wall switches; choose VANPOWER SMART to control lighting and 12 V circuits from your phone.

Frequently asked questions

What is the best electrical system for a campervan?

For most vans: a LiFePO4 leisure battery charged by a DC/DC charger while driving, an MPPT solar controller and a mains charger, with fuses and isolators near the battery. Add an inverter only if you use 230 V appliances.

What electrics do I need in a campervan?

A leisure battery, at least one charging source (alternator, solar or hook-up), a fused 12 V distribution with a switch panel, and an optional inverter for 230 V appliances.

Which is better for a campervan, 12V or 24V?

12 V for most campervans, because the vehicle and most van appliances are 12 V. 24 V halves the current for the same power and mainly helps very large systems.

How long does a 100Ah lithium leisure battery last?

It stores about 1.3 kWh. As an estimate, a 12 V compressor fridge drawing 25 to 30 W alone would run roughly 1.5 to 2 days with no charging; solar and driving extend that.

Can I install campervan electrics myself?

Many builders do, with a clear wiring diagram. The VANPOWER kit includes one with cable sections, plus free technical support. Have any 230 V installation checked by a qualified electrician.

Related guides

• 12V campervan wiring diagram, explained block by block
• LiFePO4 vs AGM batteries for vanlife
• DC/DC charger vs split charge relay