How many watts do I need?
Know your watts and you buy the right power station once: no paying for capacity you never use, and no running flat on the second night.
Choose a situation or build your own list. We work out the battery, solar and peak output you need, then show every unit in our list that fits.
1. Start from a situation
Pick one to fill in sensible numbers, then change anything.
2. What will you power?
Set how many, and the hours each runs per day. Zero means not used. The watts (W) under each name is how much power it draws while on.
3. Trip and conditions
What you need
Units that fit
Wh is battery size, so how long it lasts. W out is how much it can power at once. You need enough of both. Why both matter.
Show the working
Compare every unit in the list
How we choose
We work out the battery size, solar panel size and peak output your devices need. Every unit in the list that meets all of them is a candidate, whatever the brand.
We then show the best on each measure, such as smallest that fits and lightest to carry. One unit can win more than one.
Commission rates aren't part of our data, so they can't affect which units appear. Full method.
Specs for 34 units from EcoFlow, Jackery, Anker SOLIX and Bluetti, last checked on from retailer pages and spec databases, not maker spec sheets. Several sources disagree, which is flagged on the cards. Always check the maker's current specs before buying. Sun hours and efficiencies are rough UK planning figures, and motors and kettles can need more start-up power than their running watts.
Why it pays to know your watts
Portable power stations are sold by two numbers that most people never see explained: how big the battery is, and how much it can power at once. Getting either wrong costs money or leaves you in the dark.
- You don't overspend. A bigger battery costs more and weighs more. Knowing your daily use means you pay for the capacity you will actually use.
- You don't run out. Add up what you plug in and for how long, and you can see whether one battery gets you through the weekend or the power cut.
- You don't buy something that can't run your kit. A kettle or power tool can draw more at once than a small unit can supply, however big its battery is.
- You carry the right weight. Units range from about 3 kg to over 50 kg, which matters if you are lifting one in and out of a car.
How the power sizer works
- Say what you will power. Pick a situation such as a camping weekend or a power cut, or build your own list of devices and the hours each runs.
- Get your numbers. The sizer works out your daily energy use (in watt-hours), your peak load (in watts) and the solar panels needed, if you want to recharge as you go.
- See what fits. Every unit in our list that meets those numbers is shown, from EcoFlow, Jackery, Anker SOLIX and Bluetti. Each is ranked on spec measures such as size and weight, never on commission.
Common questions
How many watts does a fridge use?
A small camping fridge typically draws about 45 W while its compressor is running. Over eight hours that would be about 360 Wh if it ran the whole time. In practice compressors switch on and off, so real use is often lower.
What is the difference between watts and watt-hours?
Watts measure how much power something draws at a moment. Watt-hours measure how much energy it uses over time, so they set how long a battery lasts. A 60 W laptop running for four hours uses 240 Wh. Watts vs watt-hours, explained.
What size power station do I need for camping?
For a two-night weekend with lights, phones and a laptop, the sizer works out roughly 1,000 Wh of battery. Add a fridge and the number rises quickly. Three worked examples for camping.
Can a portable power station run a kettle?
Some can. A typical kettle draws about 2,000 W, so the unit's output has to be comfortably above that. A short boil does not use much energy, so the output rating, not the battery, is usually what limits you. How many watts a kettle uses.
How accurate is the sizer?
It is a planning guide. It assumes typical efficiencies and rough UK sun hours, and some devices, such as motors and kettles, can need more power at start-up. Always check the maker's current specs before you buy. How we choose.
Does commission affect which units are shown?
No. Commission rates are not part of the data behind the tool, so they cannot influence which units appear. Where we do earn a commission, we say so. Affiliate disclosure.