What does cost per watt-hour mean?

We track and compare portable power stations by cost per watt, so you can find the best value faster. Our database covers 500+ models from brands like EcoFlow, Bluetti, Jackery, and Anker. We refresh prices daily. However, the cheapest station is not always the right one, so we also compare capacity, output, weight, and ports side by side.

Key takeaways, terms, runtimes & FAQ

Key takeaways

Compare cost per watt-hour, not just the sticker price.
Size continuous output for your largest appliance, plus a 20% buffer.
Choose LiFePO4 batteries for longer cycle life.
Check solar input if you plan to recharge off-grid.
Weight and ports matter as much as capacity for camping and travel.

Power station terms, defined

Capacity (Wh): How much energy the battery can store.
Continuous output (W): The steady power the inverter can deliver.
Peak or surge output (W): A short burst for motor startup.
Cost per watt-hour: Price divided by capacity. Lower is better value.
Cycle life: The number of full charge cycles before capacity fades.

What can a power station run?

Runtimes below are rough estimates for a 1,000 Wh station. Your device may draw more or less, so check its label.

Appliance	Typical draw	Runtime on 1,000 Wh (approx.)
Phone or tablet	5–20 W	50+ hours
LED light	10 W	~100 hours
Laptop	45–65 W	15–22 hours
12V camping fridge	40–60 W	16–25 hours
50-inch TV	80–120 W	8–12 hours
Coffee maker	800–1,200 W	Under 1 hour

What size power station do I need?

First, add the watts of everything you will run at the same time. Next, add 20% for surge and inverter losses. Finally, multiply that number by the hours you need.

Capacity (Wh) = Total watts × Hours
Cost per watt-hour = Price ÷ Capacity (Wh)

How to choose the right power station

1List every device you plan to power, plus its wattage.
2Add the watts for devices that run at the same time.
3Add 20% for surge and inverter losses.
4Multiply watts by hours to find your capacity in watt-hours.
5Divide price by capacity to compare cost per watt-hour.
6Check ports, weight, and solar input for your use case.

Frequently asked questions

What does cost per watt-hour mean?: It is the price divided by the battery's capacity in watt-hours. A lower number means more stored energy for each dollar you spend.
What size power station do I need?: Add the watts you will run at the same time, then add 20%. Multiply that total by the hours you need to find your capacity.
Are LiFePO4 batteries better than other types?: For most buyers, yes. LiFePO4 lasts more full charge cycles than older NMC cells, which matters when you use it often.
Can a power station run a refrigerator?: Many can, but check the fridge's continuous draw and startup surge against the station's output before you rely on it.
Do I need solar panels?: Only if you plan to recharge away from a wall outlet. Recharge speed depends on panel watts, sunlight, and the station input.
Are the prices on WhichWatts accurate?: We refresh prices daily, but retailers can change them at any time. Always check the live price before you buy.

Sources and methodology

Our comparisons use manufacturer specifications and current retailer prices. We label estimates clearly and update this page as data changes.

Last reviewed: August 2026.