how recommendations on this site are made
Short version: by reading specifications carefully, checking them against published data and standards, and being explicit about what has not been verified.
This is a researched resource, not a test lab. That distinction matters enough to put at the top rather than bury.
what the research actually is
Manufacturer specifications, read properly. The single most useful skill in this category is knowing which number you are looking at. A power station rated at 3,600W is quoting surge. Its continuous output is lower, and continuous output is what runs a device overnight. A generator rated at 22kW produces that at sea level, at 77°F, with clean fuel and a fresh filter. Published capacity and usable capacity are different numbers, and the gap is where people get caught.
The device side of the arithmetic. Backup power questions are really two questions: what does the device draw, and for how long. A CPAP without a humidifier draws very little; with the heated humidifier and a heated hose it can draw five times as much. A home oxygen concentrator draws enough that battery-only backup is usually not realistic, and this site says so rather than selling you a battery anyway.
Published standards and safety guidance. Carbon monoxide risk, transfer switch requirements, and fuel storage rules come from published standards and manufacturer instructions, not from opinion.
Owner and installer reports. Warranty patterns, parts availability and what fails after three years is not in a spec sheet. It is in owner groups and electrician forums. This is genuinely useful and it is genuinely second-hand, so it is described that way.
what this site does not do
No bench testing. There are no runtime figures here from a stopwatch in my house. An earlier version of this site claimed detailed hands-on testing — specific measured efficiencies, multi-day runs, a fleet of units evaluated over three years. None of that testing happened, and all of it has been removed.
No scores out of ten. A decimal point implies a measurement. Where one product is the better choice, this site says which and why, and says who should buy the other one instead.
No unsourced numbers. If a figure cannot be traced to the company that published it, it does not go on the page.
what disqualifies a product
- Continuous output that will not actually carry the device it is being recommended for.
- A manufacturer that publishes only peak figures and will not state continuous ones.
- Any indoor-use claim on a fuel-burning generator. That is a carbon monoxide hazard, and no runtime figure makes it acceptable.
- A product that cannot be bought — discontinued lines and permanently out-of-stock models come off the list rather than sitting there.
corrections
If a figure here is wrong, that is worth more to me than looking consistent. Send the page where the correct number is published and it will be fixed and re-sourced.
the disclosures
Does anyone pay to be here? No. No manufacturer has editorial input and nobody pays for placement.
How does the site make money? Affiliate commissions. Commission does not change what gets recommended.
Are you an electrician? No, and nothing here replaces one. Anything involving a transfer switch or your panel needs a licensed professional.
Is this medical advice? No. If a device keeps someone alive, your equipment supplier and their clinician belong in the backup plan.