Compare

How to read this page

Watt-hours: how much power a box holds. A bigger number means the box runs your things for more hours. If you only look at one row, look at this one.

Watts: how fast something uses power. This row tells you how many things the box can run at the same time. A fridge and a router need very little. A microwave or a space heater needs a lot.

Surge: a short burst some things need to start. A fridge or a pump asks for extra power for a second when it starts. A box with a higher surge number handles that start without shutting off.

The “Fridge + Wi-Fi” row is our own math, not the maker’s. We add the watts of a refrigerator and a Wi-Fi router, keep 85% of the box’s watt-hours, and divide. Estimates. Your devices may use more or less.

How to use this page

1. Pick the box you are thinking about.
2. Pick one that is a bit bigger or a bit smaller.
3. Read the “Fridge + Wi-Fi” row. That is about how many hours each one gives you on a normal night.

Which row matters for you

• You want the fridge to last the night. Look at watt-hours first. More watt-hours means more hours.
• You want to run a microwave, a kettle or a heater. Look at watts first. If the box gives fewer watts than the thing needs, it will not run it at all.
• You will carry it up stairs or take it camping. Look at weight. The big boxes are heavy. Check that row before you choose.
• You only need phones, a lamp and Wi-Fi. A small box is enough. A bigger one is heavier and harder to move.

When two boxes look the same

If the hours are close, we say “about the same.” We call it a tie when the gap is under 3%. In a tie, pick the lighter box, or the one that gives more watts if you plan to run something big.

You can add a third box with the “Add a third box” button. The bars always compare the boxes on the screen with each other: the longest bar is the biggest number in that row, not the biggest box on the market.

What this page does not tell you

It does not tell you how loud a box is, how many years the battery lasts, or how long it takes to charge. For those, read the maker’s manual and its warranty page before you buy.

Where the numbers come from

We read each number on the maker’s own page or manual, and we link that page on each box’s own page. When we could not confirm a number, the row says “We're checking” and we leave it out of the math. We have not measured these boxes ourselves.

We do not show prices or star ratings. Prices change every day, and Amazon shows the latest one. See how we check every number →