How we pick

Why we say that so plainly

When we examined eleven competing pages while planning this site, six of them made testing claims with no supporting evidence — titles like "12 Best Portable Home Backup Generators (Tested & Reviewed)" and "5 Best Dual Fuel Inverter Generators: Hands-On Test".

Testing a dozen 250 lb generators is a serious logistical undertaking requiring space, fuel, load banks and instrumentation. The claim is also trivially falsifiable by anyone who asks for the data. We are not going to join that, and the words "we tested", "lab tested", "field tested" and "expert-tested" appear nowhere on this site.

What we actually do

1. Every specification is retrieved, not remembered

Product specifications come from each item's live listing data — the manufacturer's own published running and starting watts, engine displacement, outlet configuration, runtime, weight, decibel rating, total harmonic distortion, safety features and warranty — pulled programmatically rather than retyped from a secondary source.

That matters because it makes a remembered number structurally impossible. If a figure appears on this site, a machine fetched it from the manufacturer's listing.

2. Appliance wattages come from two published charts, both cited

All the load figures behind the calculator and the sizing guides are transcribed from two published sources: the Eugene Water & Electric Board's generator sizing chart (a public utility) and Champion Power Equipment's quick reference wattage chart (a manufacturer). Both are linked on the appliance wattage chart page.

Where they disagree, we show both. A refrigerator is 400 running watts to Champion and 700 to EWEB; a window air conditioner is 1,200 to one and 3,250 to the other. Neither is wrong — they describe different appliances — and that disagreement is the most useful thing on the page, because it is why a single confident number is misleading.

3. Where nobody publishes a figure, we say so

This is the part we are most deliberate about. Central air conditioning, well pumps above 1/3 HP and full electric ranges are absent from our appliance data, because neither cited chart publishes them — and those are precisely the loads that most often decide which generator somebody buys.

Printing an invented figure for the most consequential load on the list would be the worst thing this site could do. So instead we tell you how to read it off your own equipment's nameplate, and the calculator accepts it as a custom load.

4. We name the gaps in a manufacturer's own documentation

This is where a careful reading adds something a spec table does not. Across the machines we cover:

• Champion, Westinghouse and WEN publish running and starting watts for every fuel their machines support. DuroMax, DuroStar and Generac's tri-fuel do not — which means sizing for propane or natural gas on those machines is guesswork, and we say so on each one.
• Only Champion states a measurement distance with its decibel ratings on some models. Others publish "as low as" figures with no distance, and WEN markets machines as quiet while publishing no rating at all — comparing the noise to a conversation instead.
• Total harmonic distortion is published by most inverter machines and by a few conventional ones. Its absence on a machine sold on its inverter credentials is worth noticing, and we note it.
• Carbon monoxide shutdown is now common and still not universal. Westinghouse's WGen9500DF lacks one; its WGen10500DFc has one. We check per machine, never by brand.

How prices work

No price appears in prose anywhere on this site. Every price comes from a live data feed with the date it was checked attached, and the layer that reads it has a freshness gate: past 48 hours, every figure disappears and the button falls back to "check price".

That design is deliberate. If the daily refresh stops for any reason, the site goes silent about prices rather than quietly showing month-old numbers. The failure mode is an absence, never a false claim.

How the scores work

Every product carries per-criterion scores and a headline figure out of ten. These are our editorial judgment of how well a published specification serves home backup use, scored against criteria chosen for that product's category — fuel flexibility matters for a generator and is meaningless for a transfer switch, while panel fit certainty is the whole story for an interlock kit.

How products get chosen in the first place

1. 1Real, currently-sold models, identified from the keyword research behind each page.
2. 2Verified against a live product lookup, which is where the ASIN, the image and the published specification all come from. A product that does not resolve does not go on the site.
3. 3Scored against category criteria from those published figures.
4. 4Ranked, with every compromise named. A recommendation with no downside reads as an advert, which is why the data model makes at least one real limitation mandatory on every product.

What we will not do

• Claim to have tested anything.
• Invent a specification, a price, a rating or a review count.
• Publish a wattage figure we cannot cite.
• Rank by commission. Where Amazon is cheaper than a brand-direct option, Amazon is the link — buyer-first beats commission, every time.
• Describe installation steps for work that is licensed. We cover what to buy; your electrician installs it.
• Present a stock photograph as this site's own equipment or work.

Tell us when we are wrong

A methodology is only worth anything if it survives contact with readers who know more than we do. If a figure here is wrong, email contact@generatorandbackup.com with the page and the figure, and we will check it against the source and fix it.