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Power station spec sheet checklist

By the Ferncharge team · Figures last checked

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The short answer: a power station has to pass two tests. Can it supply the power (watts) your appliances need at once, and does it store enough energy (watt-hours) for as long as you need them? EcoFlow's UK explainer puts it this way: a watt is "the rate at which energy is used or delivered at a given moment", and a watt-hour "measures energy used over time" (EcoFlow UK). Every other line on the spec sheet is about how, where and how fast. This checklist takes each column of our spec table in turn.

We explain what makers state. Ferncharge has not tested these products, and we don't rank them.

Watts and watt-hours, worked through

For a steady load, energy (Wh) = watts × hours. An example with invented figures: a 40 W load running for 5 hours needs 200 Wh at the appliance, and two of them need 400 Wh.

That's at the appliance. The power station loses some energy in its inverter and keeps some capacity in reserve, so you need more rated capacity than that. Our methodology page gives the factors we use, and the sizing calculator applies them. If you only know an appliance's volts and amps, watts = volts × amps (EcoFlow UK).

The checklist

Work through each line for the appliances you'll actually run together.

  1. Capacity (Wh). The stored energy: it sets how long things run. Rated capacity isn't all usable from the sockets. See why your power station runs out faster than expected.
  2. Battery chemistry and cycle life. LiFePO4 (LFP) or NMC, and how many cycles to what share of capacity. Bases differ between makers. See LiFePO4 vs NMC.
  3. Continuous AC output (W). The most the mains sockets supply at once, all sockets together. It must cover everything you'll run at the same time.
  4. Surge, peak or boost (W). A brief higher figure for start-up spikes, or a mode for heating devices. These aren't continuous ratings. See what is surge power?
  5. Waveform. Whether the maker states a pure sine wave output, which matters for motors and some medical and audio equipment. See what does pure sine wave mean?
  6. UK sockets. How many 230 V sockets, and whether the model is sold with UK sockets.
  7. 12 V car socket. Its current rating (A) decides what 12 V kit it can run, such as a cool box or diesel heater. See 12V fridge or cool box.
  8. USB-C output. The stated watts per port, and whether ports share a total. Laptops can charge from USB-C, and Starlink lists a USB-C option for its Mini kit, which skips the inverter. See laptop and monitor and Starlink.
  9. UPS or pass-through. Whether it can take over when the mains fails, with the stated switchover time, and what the maker says it's suitable for. See can you charge it while using it?
  10. Charging time and inputs. Mains charging time, any fast-charge mode, and car input. See how long does it take to charge? and recharging from your car.
  11. Solar input. Not just the maximum watts: the voltage range and current limit too, checked against your panel. See is a solar panel compatible? and what size solar panel do you need?
  12. Low-load and standby settings. ECO modes and timers that switch outputs off. See why it switches off with a small device.
  13. Temperature ranges. Charging, use and storage often have different ranges. Write each one down separately from the manual.
  14. Weight and size. Compare them with where you'll carry and store it, and leave room for the ventilation the manual asks for.
  15. Warranty (UK). The length, what it covers, and how a UK customer makes a claim. Find the warranty document, not just the headline.
  16. Flying. The Civil Aviation Authority doesn't allow lithium batteries over 160 Wh in passenger baggage (CAA), so check the capacity before you plan to fly with one. See flying with a power station.

Gaps and dates

  • Write down what the spec sheet doesn't say. Usable AC energy, combined port limits, fan noise or accessory availability are often missing. Ask the maker before you buy, rather than filling the gap with a guess.
  • Note the date you checked. Makers update pages. Our spec table shows the date each row was checked against the maker's page.
  • Don't buy on the biggest number. A model with more capacity can still fail the power test, and a boost mode isn't a substitute for a continuous rating.

Next steps

  1. Work out your figures with the sizing calculator.
  2. Compare models on the spec table, which lists each maker's stated figures side by side, in alphabetical order.

FAQs

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

Watts are power at a moment. Watt-hours are energy over time: watts multiplied by hours. A power station needs enough of both.

Does a bigger battery mean it can run more powerful appliances?

Not on its own. The continuous AC output decides what it can run; capacity decides for how long.

What should I check first on a spec sheet?

The continuous AC output against the appliances you'll run together, then the capacity against how long you need them.

Related: Spec table · Sizing calculator · LiFePO4 vs NMC · Methodology

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