Use-case guides

Camping, van-life, and home-backup sizing guides. All math uses the same calculator defaults.

Example sizing for a 12-hour outage: mini fridge 40 watts times 12 hours is 480 Wh, laptop 180 Wh, LED 50 Wh, phone 20 Wh, total 730 Wh. A 15 percent buffer makes 839.5 Wh. Divided by 0.90 depth of discharge and 0.90 inverter efficiency, the AC nameplate is about 1,036 Wh, which fits the about 1,000 Wh class (results 513 to 1,152). Compare that result to the station label. All 12 V DC devices would be about 933 Wh. The fridge 40 W is an average because the compressor cycles. — EXAMPLE. 480 + 180 + 50 + 20 = 730 Wh. 730 × 1.15 = 839.5. 839.5 / 0.90 / 0.90 = 1,036.42, shown as ~1,036 Wh. 12 V DC skips the inverter: 839.5 / 0.90 = 932.78, shown as ~933 Wh. Fridge 40 W is an average over the window.

Weekend camping power station size — Size a portable power station for a weekend camping trip using Wh/day and WattNeeds defaults.
Camping fridge Wh needs — Duty cycle and real Wh/day: CFX3 35 at 32°C is 282 Wh/day. Holding 7.5 A for 24 h is 2,160 Wh. 12 V uses η=1.00. No freezer Ah/h is printed.
CPAP night on a power station — AirSense 10 at a printed 10 cm row: heated tube plus humidifier is 472.32 Wh versus 89.28 Wh on SlimLine only. DC converter uses η=1.00; AC inverter uses η=0.90. A 90 W supply rating is not the night.
Home outage essentials — power station size — EnergyGuide kWh/year → Wh/day, then two AC stacks: light essentials, or essentials plus one cited full-size fridge. No HVAC, no transfer switch, no panel backfeed.
Van-life daily Wh budget — One parked day: CFX3 35 test point plus plug-in loads. 12V/USB uses η=1.00; AC uses η=0.90. Hot-cabin fridge uplift is a labeled what-if.
Starlink / hotspot power draw planning — Mini sheet average is 25–40 W. 40 W × 8 h is 320 Wh: DC nameplate 409 Wh (η=1.00), AC nameplate 454 Wh (η=0.90). Standard 4X is a separate 75–100 W band.
Solar harvest vs battery Wh — Panel W × peak sun hours × 0.86. Seattle annual planning hours, 200 W, is 686.28 Wh/day at the battery: 52.95 Wh over camping on the AC path (633.33 Wh) and 50.48 Wh over a 12 V van day (635.8 Wh), 280.39 Wh short of an AC outage day (966.67 Wh). A dark day still uses solar = 0.
500 Wh vs 1000 Wh — where each label stops — A 366 Wh camp day on 12 V is 468 Wh for one day (a 500 Wh label covers it) and 935 Wh for two (1,000 Wh is the floor). A 1,050 W microwave input fits the watt-hours and fails a 500 W inverter.
1000 Wh vs 2000 Wh — where each label stops — A 385 Wh van day on 12 V is 984 Wh for two days (a 1,000 Wh label covers it) and 1,476 Wh for three (2,000 Wh is the floor). A 2,000 W oven input fits the watt-hours and fails an 1,800 W continuous line.
Diesel heater electrical draw (van) — Fuel makes the heat. Airtronic D2 catalogue: 8 W low, 34 W power, 100 W at start. An 8 h cold night is 277.333 Wh electrical, 354 Wh nameplate on 12 V (η=1.00). A 100 W bound on the 40 s cleaning glow adds about 1.111 Wh per shutdown: cold night about 356 Wh DC, cycling night about 96 Wh DC. The inverter path is η=0.90, and only through a 12 V adapter.
Cooler vs compressor fridge energy — Compare ice cooler vs 12V compressor fridge energy and power-station implications.
Rainy-weekend no-solar sizing — Size portable power for a rainy camping weekend with little or no solar harvest.
Surge traps — startup watts vs watt-hours — Running watts, startup watts, and Wh are three checks. EdgeStar's 575 W start misses a 500 W inverter. A Franklin 58.8 A locked-rotor current misses a 4,800 W surge screen. A 450 W window AC for 8 hours names to 5,111 Wh.

Wh calculator — nameplate = (Wh/day × days × 1.15) / (0.90 × 0.90).