How to Set Up a 12V Battery System for Vanlife

Going off-grid in your campervan? A 12V battery system is the heart of your vanlife setup — powering your lights, fridge, fans, USB chargers, and more. In this step-by-step guide, we’ll show you how to build a beginner-friendly electrical system that’s safe, reliable, and totally DIYable.

Whether you’re converting your first van or optimizing an existing setup, this guide walks you through planning, components, wiring, and installation.

🔋 What Is a 12V Campervan Electrical System?

Most campervans run on a 12V DC system because it’s efficient, low voltage, and perfect for off-grid use. Unlike AC systems, it doesn’t require massive infrastructure or high voltage safety certifications.

Key components include:

• Leisure battery – typically AGM or LiFePO4
• Charging sources – solar panels, alternator (via DC-DC charger), shore power
• Distribution system – fuse block, cables, switches
• Loads – all your appliances: lights, fridge, fans, etc.

New to battery types? Read our full guide: RV Battery Types Explained.

🧠 Planning Your Power Setup

Before you buy anything, plan how much power you’ll need. The easiest way: add up the watts of each device, calculate how long you’ll use them per day, then convert to amp-hours (Ah).

• 12V fridge – ~30-50Ah/day
• LED lights – 1–3Ah/day
• MaxxAir fan – ~10–15Ah/day
• Phone charging – ~2Ah/day

➡️ Use our free tool to simplify it: Camper Battery Capacity Calculator

🔧 Choosing the Right Components

Here’s a basic component list for a beginner-friendly 12V setup:

• Battery: 100–200Ah LiFePO4 or AGM
• MPPT Solar Charge Controller: Victron or Renogy
• DC-DC Charger: For charging via alternator while driving
• Fuse Box: With labeled blade fuses
• 12V Cables: Proper gauge (e.g. 10AWG, 6AWG, 2AWG)
• Inverter (optional): To run AC devices

Compare AGM and lithium in detail: AGM vs Lithium – Pros & Cons

🪛 Installing the System (Wiring Guide)

1. Mount your battery in a secure, ventilated space using a box or straps.
2. Install the solar controller near the battery for efficient voltage regulation.
3. Wire in the fuse block and label every circuit clearly.
4. Connect your DC-DC charger to the starter battery via an ignition line.
5. Install all loads (lights, fan, fridge, etc.) with fuses.

Coming soon: downloadable PDF wiring diagrams. Need charging help? Read DC-DC vs Shore Power.

🧰 Safety Tips for DIY Electrical Work

• Disconnect all power before making connections
• Use the right fuse rating for each device
• Check polarity before powering on
• Secure cables with conduit and mounts
• Double-check grounding and bonding

🛒 Sample Shopping List

• 1x 100Ah LiFePO4 Battery
• 1x Victron MPPT Solar Controller
• 1x 20A DC-DC Charger
• 1x Fuse Box + Blade Fuses
• 10AWG/6AWG Wire Kit
• 1x Battery Monitor (e.g. Victron SmartShunt)
• 1–2x 100W Solar Panels

📦 Final Tips

This setup is ideal for weekend trips, digital nomads, or full-time vanlifers running 12V appliances. You can scale it up later with more batteries or solar.

Want even more power? Explore our best AGM RV Batteries for advanced setups.