Off-Grid Van Electrical System: What You Actually Need

· 3 min readElectrical System
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Off-grid van electrical comes down to one equation: daily energy in must equal or exceed daily energy out. Here's what that means practically.

What "off-grid" actually demands

Off-grid means no shore power hookups — you rely entirely on solar, driving (via DC-DC charger), or a generator for recharging. The electrical system must be sized for your typical daily load plus enough buffer for cloudy days or low-mileage weeks.

Minimum viable off-grid system

For typical van life loads (fridge, laptop, phone, lighting, fan — no induction cooking):

ComponentMinimum specWhy
Battery200Ah LiFePO42–3 days autonomy at 600Wh/day
Solar300WSelf-sustaining in moderate sun
MPPT charge controller30–40A at 12VMatches 300–400W panel array
DC-DC charger30A (Renogy DCC30S or equivalent)Alternator backup on driving days
Fuse/breaker200A main fuseSized for battery and inverter
Shunt/monitorVictron SmartShuntKnow your actual state of charge

This system costs roughly $1,200–$1,800 in components and handles most van life scenarios comfortably.

Scaling up for heavy use

If you run an induction cooktop, work from a desktop setup, or frequently camp in cloudy climates:

ComponentUpgraded spec
Battery300Ah LiFePO4 (or 2× 200Ah in parallel)
Solar400–600W
DC-DC charger40A (Victron Orion XS or Renogy DCC50S)
Inverter2,000W pure sine

What drains a battery fastest

The two biggest loads in most van builds:

  1. 12V compressor fridge: 40–80Wh per day depending on ambient temp and thermostat setting. Highest single daily draw but spread over 24 hours.
  2. Induction cooking: 1,500–1,800W for 15–30 minutes = 375–900Wh per cooking session. Often the biggest single-event drain.

If you run induction cooking twice a day, you might need 800+ additional Wh beyond your baseline — which means more battery and solar than a non-cooking build.

Off-grid realities

Sunny weather: 300–400W solar generating 1,200–1,600Wh/day easily covers a 600–800Wh daily load. Battery stays topped up.

Overcast weather: 300W solar might produce only 200–600Wh. You draw down the battery. After 2–3 cloudy days, you're driving to recharge or plugging in somewhere.

Winter at northern latitudes: Fewer peak sun hours, panels may be snow-covered, and heating loads are higher. Many full-timers migrate south in winter or use a generator as backup.

Parking in the shade: Solar produces little or nothing. The DC-DC charger while driving becomes the primary recharge source.

Size for your worst-case week, not your best day

Design the system for a week of overcast weather, not a sunny July day at 40° latitude. A system that handles the bad week comfortably handles the good week effortlessly.

VP

Roam Wired

We help self-builders design safe, reliable campervan electrical systems. Our tools and guides are free — always.

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