Free Camping Power Budget Calculator | Off-Grid Solar & Battery Planner

Build your power budget

Trip settings

Trip length (days)

Peak sun hours/day

System loss (%)

System loss accounts for inverter, wiring, and charging inefficiencies. 15% is typical for portable stations.

Your devices

Device

W

Qty

Hrs/day

Days

Standby W

Battery status

0%

Daily energy 0 Wh

Trip energy 0 Wh

Battery needed 0 Wh

Recommended station 0 Wh

Solar recharge

Solar needed 0 W

With system loss 0 W

Solar sizing assumes 4 peak sun hours per day. Adjust in trip settings.

How camping power planning works

Watts vs Watt-hours

Watts (W) measure power — how fast a device uses energy. Watt-hours (Wh) measure total energy used over time. A 60W laptop running 4 hours uses 240Wh. Your battery is rated in Wh, so this is the number that matters most.

Battery capacity

Portable power stations are rated in Wh. To cover your trip, add up all device Wh per day, multiply by trip days, then add 20–30% buffer. Never plan to use 100% of battery capacity — 80% depth of discharge is a safe real-world limit.

Solar charging

Solar panels are rated in watts under ideal sun. Real-world output is lower — typically 60–75% of rated wattage. Use peak sun hours (PSH) for your location: 3–4 in overcast regions, 5–6 in sunny climates. Divide daily Wh by PSH to size your panel.

Typical camping device wattage

Device	Typical watts	Typical daily Wh	Notes
Phone	5–10 W	10–30 Wh	Charging, not continuous draw
Laptop	45–85 W	100–300 Wh	Varies with workload
Camera battery	8–15 W	15–40 Wh	Charger draw
LED lights	3–10 W	15–50 Wh	Per light
Fan	10–25 W	40–150 Wh	USB or 12V
Portable fridge	40–60 W	300–600 Wh	Compressor cycles — not continuous
CPAP	30–60 W	200–400 Wh	Without humidifier: ~30W; with: ~60W

These are typical ranges. Always check your device label for exact wattage. USB devices often list amps at 5V — multiply to get watts.

Energy-saving strategies

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Avoid phantom loads

Unplug chargers and inverters when not in use. Standby draw can add 5–15W continuously.

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Pre-chill your fridge

Cool your portable fridge at home before leaving. It will cycle less on battery.

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Use LED lighting

LEDs use 80% less power than incandescent. A 5W LED can light your entire campsite.

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Charge devices in bulk

Charge all devices during peak solar hours. This uses solar directly instead of draining the battery.

Frequently asked questions

How do I calculate my camping power needs?

List every device you'll bring. For each, note its wattage (W) and how many hours per day you'll use it. Multiply to get daily Wh. Add all devices together, multiply by trip days, then add 20–30% buffer for safety and battery health. That total is your required battery capacity in Wh.

What size portable power station do I need for camping?

For a weekend trip (2–3 days) with phone, lights, and a small fan, a 500Wh station is often enough. If you're running a portable fridge or CPAP, plan for 1000–1500Wh. For a week off-grid with multiple devices, 2000Wh+ is realistic. The calculator above gives you a precise recommendation based on your actual devices.

How much solar do I need to recharge my camping battery?

Divide your daily Wh by your location's peak sun hours (PSH). If you use 400Wh/day and get 4 PSH, you need at least 100W of solar. Add 20–30% for real-world losses — so a 130–150W panel is safer. Remember: solar only works while the sun is out, so combine with battery storage for overnight use.

Can I run a CPAP machine while camping?

Yes — but CPAP machines are power-hungry. Without a humidifier, most draw 30–60W. Over 8 hours that's 240–480Wh per night. For a 3-night trip, you'd need 720–1440Wh just for CPAP. Look for a travel CPAP (some draw under 20W) and always use a DC adapter when possible — it avoids inverter losses.

What's the difference between watts and watt-hours?

Watts (W) = instantaneous power draw. Watt-hours (Wh) = total energy consumed over time. A 100W device running for 2 hours uses 200Wh. Your battery is rated in Wh — that's the number that tells you how long it will last. Always calculate in Wh for energy planning.

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