Power anywhere
Off-Grid Power for a Road Trip: Run a Fridge, Devices & Starlink
How to size a battery and solar setup to run a 12V fridge, your devices, and Starlink off-grid — the daily power-budget math, the solar sizing rule, and the gear that makes it simple.
A cold fridge, charged phones, lights, and internet at a campsite with no hookups — that’s the promise of a portable power setup. The trick is sizing it right: too small and your fridge dies overnight; too big and you’re hauling a battery you never use. It comes down to one number — your daily watt-hours — and a little solar to top it back up.
This guide shows the power-budget math, how to size a battery and a solar panel to your trip, and where a one-box power station beats a DIY build. The printable PDF includes the worksheet so you can size your own rig.
What you’ll learn
- How to calculate your daily power budget in watt-hours
- What a 12V fridge, devices, and Starlink actually draw
- How to size a battery / power station to last a day (or three)
- The solar sizing rule of thumb — and why region matters
- Power station vs. DIY battery build — which to choose
Start with your daily watt-hours
Everything starts with watt-hours (Wh) — and capacity is just Volts × Amp-hours, so a 12V 100Ah battery holds ~1,200Wh. List each device, multiply its watts by hours used per day, and add it up.
A realistic day: a 12V compressor fridge averages ~400Wh/day (a bigger 60L unit in hot weather closer to ~600Wh), phones and a laptop ~150–300Wh, LED lights ~50Wh, and a Starlink Mini at ~20W for 10 hours ~200Wh. That’s roughly 800–950Wh for a connected campsite day.
Then pad it: divide by ~0.85 for conversion losses (or run 12V devices on DC directly to skip the ~10–15% inverter loss), and add ~25% headroom for cold nights and cloudy days.
Sizing the battery
Match capacity to how long you need to go without recharging. For the ~800–950Wh/day example: a 1,000Wh power station covers one day with a thin margin; a 1,500–2,000Wh unit gives a comfortable buffer or stretches to two days; a 500Wh unit is fine for just devices + lights (no fridge).
Use LiFePO4 (LFP) if you can — it’s the standard in modern power stations for its long cycle life and better thermal safety. Running your fridge and devices on the station’s 12V/USB outputs (rather than through the AC inverter) squeezes out meaningfully more runtime.
Adding solar to stay out longer
Solar is what turns a weekend setup into an indefinite one. Daily solar harvest ≈ Panel Watts × Peak Sun Hours × ~0.85. A 200W panel at 5 peak sun hours makes roughly 850Wh/day — about enough to replace the connected-campsite day above.
Region matters a lot: the desert Southwest gets ~6–7 peak sun hours, the Northeast ~4, the Pacific Northwest ~3, so the same panel makes far more power in Moab than in Oregon. A power station with a built-in MPPT input lets you plug the panel straight in — MPPT harvests ~20–30% more than older PWM and saves you wiring a separate controller.
The setup, step by step
- Add up your daily watt-hoursList every device (watts × hours/day) and sum it. Include the fridge, phones/laptop, lights, and Starlink if you carry one.
- Pad for losses + bufferDivide by ~0.85 for conversion losses and add ~25% headroom for cold and clouds.
- Pick a battery/station to matchChoose a Wh capacity that covers the number of days you want between charges. LiFePO4 for longevity.
- Size your solarPanel Watts × your region’s peak sun hours × 0.85 should roughly replace your daily use. 200W is a common sweet spot.
- Run DC-direct where you canPower the fridge and devices off 12V/USB outputs instead of the AC inverter to gain runtime.
Get the printable field guide (free)
Four pages with the diagrams, the runtime table, and the safety checklist — clean enough for the glovebox or the group chat. Drop your email and it downloads instantly.
Recommended gear
Some links below are affiliate links. If you buy through them, Roamward may earn a small commission at no extra cost to you — it helps keep these guides free.
The power
A one-box power station is the simplest path; the rest is for DIY builds.
The simplest off-grid power — battery, inverter, and MPPT in one box. Jackery/EcoFlow/Anker/Bluetti run their own (better-paying) affiliate programs.
Replaces a connected-campsite day in good sun; folds flat for the trunk.
The single best off-grid upgrade — real refrigeration on ~400Wh/day.
DIY build extras
Common questions
What size power station do I need for a road trip?
For a fridge + devices + lights (+ a Starlink Mini), plan ~800–950Wh/day, so a 1,000Wh station covers a day with thin margin and a 1,500–2,000Wh unit gives comfortable buffer. Devices and lights only? ~500Wh is plenty.
How much solar do I need to run a 12V fridge?
A 12V fridge uses ~400Wh/day, and a 200W panel makes roughly 850Wh/day in good sun (Panel W × ~5 peak sun hours × 0.85), so 100–200W of solar keeps a fridge going indefinitely in sunny regions.
Is a power station better than a DIY battery setup?
For most road-trippers, yes — a power station packs the battery, inverter, and MPPT solar controller into one box with no wiring. A DIY 12V build is more cost-effective at large capacities and for permanent van installs.
Can I run Starlink off the same setup?
Yes. A Starlink Mini adds only ~20W (~200Wh for 10 hours) to your budget. See our portable Starlink Mini guide for the cable and runtime details.
Informational guide only — not affiliated with, authorized by, or endorsed by Starlink or SpaceX, or any product maker named here. Power figures are approximate and vary by firmware, conditions, and gear; always follow your equipment’s instructions and verify its ratings before use.