How to Set Up a 12V Battery System for Vanlife (Step-by-Step)
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)
- Mount your battery in a secure, ventilated space using a box or straps.
- Install the solar controller near the battery for efficient voltage regulation.
- Wire in the fuse block and label every circuit clearly.
- Connect your DC-DC charger to the starter battery via an ignition line.
- 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.