A well-designed Victron off-grid system lets you camp for days without shore power — running your fridge, lights, water pump, and even AC from batteries that recharge themselves from solar and your tow vehicle. This guide walks through the core components, how they connect, and how to size each one for a camper.
Shop the full Victron Energy range to build your system, or read on for how the pieces fit.
The core components
- Battery bank - your energy store. Lithium LiFePO4 batteries are the standard for off-grid: light, deep-cycling, and long-lived.
- Inverter/charger - turns battery DC into household AC and charges the bank from shore power. See our MultiPlus vs Quattro guide to pick one.
- Solar charge controller (MPPT) - converts solar panel output into safe battery charging. Browse solar charge controllers.
- DC-DC charger - charges your house battery from the vehicle alternator while you drive. See DC-DC converters & chargers.
- System monitor (GX) - a Victron GX device shows state of charge, solar yield, and consumption at a glance.
- Distribution & fusing - Lynx busbars and fuses/circuit protection keep the system safe and tidy.
How it all fits together
The battery bank sits at the center. Three sources charge it: solar (panels → MPPT → battery), the alternator (vehicle → DC-DC charger → battery) while driving, and shore power (pedestal → inverter/charger → battery) at a campground. On the output side, the inverter/charger supplies AC to your outlets, while DC loads draw straight from the bank through fused distribution. The GX monitor watches the whole system.
Sizing each part
- Battery bank: add up your daily watt-hours (loads x hours) and aim for 1-2 days of storage. Lithium lets you use most of its rated capacity.
- Inverter/charger: size to the continuous AC watts you'll run at once; choose 12V for small rigs, 24/48V for larger banks.
- Solar + MPPT: fit as many panels as your roof allows, then choose an MPPT rated for that array's current and voltage. New to controllers? Read MPPT vs PWM.
- DC-DC charger: match it to your alternator's capacity (commonly 30A or 50A for campers).
Wiring principles that matter
- Keep solar array voltage well above battery voltage. An MPPT works best when the array is at least ~20V above the battery's charging voltage - often easier in series/series-parallel.
- Use the right wire gauge to minimize voltage drop and heat, especially on the high-current battery-to-inverter run.
- Fuse every source and load close to the battery. Don't skip circuit protection.
Frequently asked questions
Do I need both solar and a DC-DC charger?
They complement each other: solar charges while parked in the sun, the DC-DC charger tops up while you drive. Many off-grid campers run both for reliability.
What size battery bank do I need?
Total your daily watt-hours and aim for one to two days of autonomy. A weekend boondocker needs far less than a full-time rig with AC.
Why Victron specifically?
Victron components are designed to work together, share Bluetooth/GX monitoring, and are well supported - making system design and troubleshooting much easier.
Build your system from the Victron Energy collection, or start with an inverter/charger. Ships from Upland, CA - questions about your build are welcome.