How these numbers were produced, and what we refuse to do

We do not re-host certification PDFs. When a claim depends on a safety standard or recall check, start here and verify the current document on the issuing site:

• UL 2743 — portable power pack safety standard overview (UL).
• IEC 62619 — secondary lithium cells/batteries for industrial applications (IEC).
• CPSC Recalls — search portable power / battery recalls before you buy used or clearance gear.
• Manufacturer specification pages linked from each station’s source note — the primary evidence for every nameplate figure we store.

1. Collection. Each product page is fetched once and cached, so a re-run reproduces the same dataset rather than silently drifting.
2. Spec-sheet isolation. Product pages routinely contain other products’ specifications — comparison modules, “related products” carousels, and on some vendors even the site navigation. We locate the vendor’s own specification table as the densest contiguous run of label/value rows and extract from that, discarding the rest.
3. normalization. We track 31 vendors, and they word the same specification in different ways. Values are converted to one unit each — watt-hours, watts, pounds, minutes, months — and a field is only emitted when a label and a unit pattern both match.
4. Evidence capture. Every stored value keeps a verbatim quote from the source page. This is not a note for our benefit; it is what makes step 5 possible.
5. Verification. Each value’s quote is programmatically re-checked against the source text. If the quote cannot be found, the value is discarded, regardless of how plausible it looks. A fabricated number cannot survive this, because a fabricated number cannot also appear in the vendor’s own page.
6. Physical plausibility. Surviving values are checked against physics. A complete LiFePO4 station delivers roughly 30–60 watt-hours per pound; a weight implying more than 70 Wh/lb belongs to a different product on the same page. That failure mode is real, we hit it, and it is now detected automatically.
7. Conflict reporting. Two independent extraction methods are run over every page. Where they disagree the disagreement is recorded rather than averaged away, so systematic problems stay visible.

These are not interchangeable headlines. Home and the Stations index quote the public power-station catalog (alias duplicates 301’d away); rankings need the comparability floor; Power Fit uses verified + comparable + Check Price. Pool sizes come from Affiliate Hub catalogStats on every build — the site does not keep a second denominator.

Not every vendor publishes every field. A missing value is displayed as “—” everywhere on the site and the model is excluded from any ranking that needs it. We never substitute a typical value, a predecessor’s value, or another model’s value. List price is commercial listing data tracked separately (see “Models with list price” above) — it is not one of these 19 keys and does not change brand disclosure rates.

• We do not invent reviews, ratings or testimonials. No invented people, no fictional user quotes, no made-up star ratings. Fabricated consumer reviews breach the US FTC rule on consumer reviews (16 CFR 465) and Google’s spam policies, and they are simple fraud. What we publish instead is described under owner reviews below. Our editorial analysis is written by us and labeled as ours.
• We do not invent instrumented lab scores. Editors are deep-use experience reviewers — hands-on use and owner themes are fair game when labeled. What we refuse is fake “we measured in our lab” numbers we did not take.
• We do not estimate missing specifications. A gap in the table is information: it tells you what the vendor is not willing to publish.
• We do not copy specs from other review sites. If a number is not on the manufacturer’s page, we do not have it.
• We do not present our composites as measurements. The home-backup readiness score and composite rankings are our judgment; their inputs and weights are published so you can disagree with them precisely.

Stated plainly, because a methodology page that only lists strengths is marketing.

• Vendor figures are vendor claims. Cycle life, noise and surge ratings are measured by manufacturers under conditions they choose. We verify that a figure was published, not that it is true.
• Coverage is not uniform. Larger brands publish more, so they rank in more dimensions. The power-station catalog is 120 models from 31 brands; 53 meet the Hub ≥6/19 comparability gate for rankings and Power Fit. Thin sheets stay on product pages but cannot take a ranked #1 or a Fit shortlist slot. Power Fit scores 47 verified + comparable models with Check Price links — a different pool on purpose.
• 2 models still lack a captured price. Some storefronts block our collectors (for example DJI’s Power line), so we show no price rather than an old or approximate one.
• Vendor imagery only. Where a vendor page exposes no usable product image, we show a labeled placeholder instead of stock photography that might misrepresent the product.
• Page-speed field data is opt-in RUM, not a lab claim. After analytics consent we report LCP / INP / CLS from the visitor’s browser into GA4. Chrome UX Report (CrUX) field data appears in PageSpeed Insights only after enough Chrome traffic; until then treat PSI numbers as lab or insufficient-field-data, not as a WattPicks bench score.
• Mobile checks are viewport smoke, not a device lab. We verify key templates at 390×844 (and the 720/680 CSS breakpoints) for page-level overflow and 44px touch targets. That is not a claim that every phone/OS combination was hand-tested.
• No acoustic or electrical measurements. Noise, inverter waveform quality, thermal behavior under sustained load and real-world efficiency are not knowable from a spec sheet. Where they matter, we say so and link to what the vendor claims rather than pretending to know.