How we test
We check every spec. We say what we tested and what we only read. We never take money to change a pick.
We read it
We check every number on the maker’s own page. If a number is missing, we say “We’re checking.”
We measured it
This stamp means we plugged real things in and used a power meter. Then we wrote down how long it really ran. No box has this stamp yet.
We lived with it
This stamp means the power went out, and this box kept a real home going. We tell you what worked and what did not. No box has this stamp yet.
What we do
- 1Pick boxes made for home outages.
- 2Check every spec on the maker’s page.
- 3Measure a box with a power meter when we can get one, and show the reading.
- 4Check again every few months, and fix what changed.
What we never do
- Take money to put a box on a list.
- Show star ratings or review counts we did not make.
- Show prices. They change every day.
- Say we tested something we only read about.
Where we are today
Right now every box on this site has the “Specs checked” stamp, and nothing more. We have not measured a box with a power meter yet, so no box has the “Measured by us” stamp. When we measure one, the page will show the reading.
How we do the math
We take the box size in watt-hours and keep 85% of it, because some power is lost on the way out. Then we divide by the watts your things use. That gives the hours. It is an estimate: your devices may use more or less.
Watts: how fast something uses power. Watt-hours: how much power a box holds. Surge: a short burst some things need to start.