Evidence page
Portable power station for an RV
Short answer: a portable station is a good fit for RV lights, water pump, fridge in DC mode, laptops and charging — typically 300–1,200 Wh per night. It is the wrong tool for roof air conditioning without shore power, and no capacity figure changes that.
Published 8 August 2026 · Last reviewed 10 August 2026
By Alexis Marchais, engineer and independent decision-system builder.
How this guide calculates
Stored capacity needed = nightly Wh × nights ÷ 0.765, minus usable on-board energy after inverter losses, checked night by night against declared recharge.
Observed / model inputs
- TT-30 connector arithmetic: 120 V × 30 A = 3,600 W nameplate.
- Declared per-night loads in Wh, and measured or nameplate watts for any air conditioner.
- Usable DC energy already on board, and declared alternator or solar recharge in Wh per day.
Before the Battery planning assumptions
- 2,880 W as a conservative planning ceiling on a TT-30 pedestal, not a code limit.
- 85% AC delivery and a 10% retained reserve, giving the 0.765 planning factor.
- Existing DC battery energy is credited against AC loads only after the same 85% inverter factor.
- Air conditioning is never sized from a Yes/No answer; without declared watts and hours the diagnostic escalates.
Start with shore power, not with the battery
If a TT-30 pedestal is available for the whole trip, the pedestal is the architecture and the station is a convenience. A TT-30 inlet is 120 V × 30 A nameplate — 3,600 W — but it is a connector, not a promise. Before the Battery plans against roughly 2,880 W continuous as a conservative in-house planning ceiling — not a universal code limit, and expect less on a hot afternoon at a crowded campground.
The loads that actually matter for a weekend
- LED lighting: 20–60 Wh per night.
- Water pump, intermittent: 30–80 Wh per day.
- 12 V compressor fridge: 300–700 Wh per day, the single largest steady draw.
- Laptops, phones, CPAP without a humidifier: 100–400 Wh per night.
Two nights of that is commonly 800–2,400 Wh at the outlet, before conversion losses. Apply the same 85% delivery factor and 10% retained reserve (both Before the Battery planning assumptions) and a 2,000 Wh class station is a realistic two-night unit for everything except air conditioning.
Air conditioning is the decision boundary
A single roof unit typically runs around 1,300 W and surges far higher on startup. Even four hours a night is over 5,000 Wh, before losses. That is not a portable-station problem — it is a shore power, generator, or properly installed lithium-and-inverter problem. This publication refuses to size it from a Yes/No answer: without declared AC watts and hours, the diagnostic escalates rather than guessing.
That boundary is worked out in full in decision case RV-02: a 13,500 BTU unit, six hours a day, no shore power and no soft start — arithmetic published, product refused.
The battery you already own counts — but not one-for-one
Existing house-battery energy is DC. Running AC loads through an inverter costs roughly 15% of it, so usable DC watt-hours are credited against AC loads only after that factor is applied. Alternator charging counts only when you declare both the charging watts and the hours you actually drive.
Check your own trip
Run the RV weekend check, or read the travel trailer variant.
The equations behind that check are published on the RV sizing method page, and each decision case replays a frozen situation against the live engine — including RV-01, a two-night weekend with every peak declared.
Reproducible dataset
Refrigeration is the load most RV owners size first, and its arithmetic is published separately as a reproducible dataset with visible assumptions and abstention rules.
Refrigerator outage sizing table: 15 transparent scenarios — formula, assumptions, gate states, XLSX and CSV.
Primary sources
Merchant marketing is never used as a primary source for generic arithmetic. Specific product or model specifications still require dated OEM documentation plus independent measured evidence.
- 30 amp general electrical information (RV shore power)Heartland Owners technical reference
Supports: The TT-30 connector arithmetic: 120 V × 30 A = 3,600 W nameplate.
Manufacturer/owner technical reference, not a government source. Used only for the connector arithmetic.
- PVWatts CalculatorUS National Renewable Energy Laboratory
Supports: That realistic daily solar yield is location- and season-dependent, and must be estimated rather than assumed from panel nameplate watts.
- ENERGY STAR certified residential refrigerators (product finder)US Environmental Protection Agency
Supports: The range of certified annual consumption figures behind the typical 1,000–1,900 Wh per day band used on this site.
Browse all guides, diagnostics and research — RV and travel-trailer guides, both diagnostics and the published method.