Guides and evidence
Guides, diagnostics and research
Everything published here, grouped by the job you are trying to do. Each card states the question it answers and how it was produced — an interactive diagnostic, a reproducible research table, the published method, a case boundary, or an editorial guide.
Keep a refrigerator cold during an outage
Start from the EnergyGuide number on your own refrigerator, not from a capacity chart.
- Interactive diagnosticRefrigerator outage check“Will 1,000 Wh or 2,000 Wh keep my refrigerator cold for my outage?”A two-minute check: one EnergyGuide figure, an outage length and your realistic daily recharge. Returns a plain-language verdict with the arithmetic on request.Live · deterministic rules · abstains when nothing fits
- Reproducible research tableRefrigerator outage sizing table“Where do those numbers come from, and can I reproduce them?”Converts EnergyGuide annual kWh into 24-, 48- and 72-hour capacity screens, with the formula, the assumptions and the gates capacity alone cannot answer.Reproducible · 15 published scenarios · XLSX and CSV download
- Editorial guideBattery backup for a refrigerator“How much battery backup does a refrigerator actually need?”The daily energy band, the planning factor behind it, and the decision boundary where a portable battery stops being the right architecture.Editorial · primary sources cited · reviewed 10 August 2026
- Editorial guidePortable power station for a refrigerator“Which portable power station size works for a fridge?”Why the running-watts and startup-watts gate decides more size questions than watt-hours do, and where the honest limit sits.Editorial · primary sources cited · reviewed 10 August 2026
Power an RV or travel-trailer weekend
Shore power, TT-30, the house battery you already own, and the loads you will actually run.
- Interactive diagnosticRV weekend power check“Is a portable station enough for my weekend?”Declare your shore-power situation, the battery you already have and the loads you plan to run. Returns whether the weekend closes, or why it does not.Live · deterministic rules · abstains when nothing fits
- Published methodologyRV sizing method (pillar)“How is RV power actually sized, equation by equation?”The four equations behind the RV check — daily energy, mission energy, the 0.765 usable-energy factor and the conservative system peak — plus the points where the method refuses to answer.Published equations · abstention boundaries stated · no product named
- Case boundary and abstentionDecision cases“Can I see a complete worked RV case before I trust the tool?”RV-01 shows a complete declaration that closes; RV-02 shows an air conditioner without shore power, where the same method abstains and escalates instead of naming a product.Frozen inputs · replayed against the live engine at render time
- Editorial guidePortable power station for an RV“What will a portable station cover in an RV, and what never will it?”Where a portable station fits an RV weekend, the TT-30 arithmetic, and the point at which air conditioning ends the conversation.Editorial · primary sources cited · reviewed 10 August 2026
- Editorial guidePortable power station for a travel trailer“My trailer has no alternator or inverter — what changes?”How the missing charge path changes the sizing for dry camping, and where a portable station stops being enough.Editorial · primary sources cited · reviewed 10 August 2026
When a portable battery is the wrong answer
The site's most useful output is sometimes that none of the portable options fits. These assets describe that boundary and what comes after it.
- Editorial guideInstalled backup: what to collect before you request quotes“A portable station cannot close my outage — what do I gather next?”The exact information to write down before the first installer conversation, so that conversation is a real one. Nothing is sold, requested or forwarded here.Editorial next-step guide only · no installer quotes, no lead capture, no prices, no product recommendation
- Case boundary and abstentionAbstention and case boundaries“When does this site refuse to answer?”The declared conditions under which the correct output is 'none of these fits' rather than a ranked least-bad unit, and how missing, unknown and not-applicable stay distinct states.Published rules · dated · open to correction
France / residential storage missions (fr-FR)
Three separate French missions, each with its own page: what a page treats, what it refuses to treat, and whether the evidence is closed. Nothing is merged, and the protected-circuits page recommends no product at all.
- Interactive diagnosticCoupure de courant : plusieurs appareils essentiels sur prises“Plusieurs appareils essentiels sur prises pendant une coupure ?”Simultaneous draw and the number of plugged appliances decide, not a capacity figure. The named configuration appears only after a compatible result, and no lasting price is stated.Live · fr-FR · evidence-gated · one named configuration only after a compatible result · no panel circuits, no fixed installation, no whole-home
- Interactive diagnosticStockage solaire : valoriser un surplus photovoltaïque existant“Valoriser un surplus photovoltaïque déjà produit ?”For a roof installation already in service: what leaves for the grid today, and whether storing it is coherent. An abstention above the declared surplus range is a valid terminal result.Live · fr-FR · evidence-gated · self-consumption retrofit only · no outage, no backup outlet, no guaranteed saving
- Case boundary and abstentionCircuits protégés : qualification seulement“Protéger des circuits du tableau : que faut-il prouver ?”Dated manufacturer figures on one side; grid separation and changeover, protections, the circuits actually backed up, commissioning and NF C 15-100 / Consuel still to be confirmed on the other.Qualification only · fr-FR · no product, no merchant action, no price until the electrical architecture is proven
Check the method before trusting the answer
Every rule, assumption and correction is published and dated.
- Published methodologyMethodology“How is any of this calculated?”The sizing policy, the catalog evidence policy, and the rule that ranking is computed before any commercial layer is applied.Published · dated · usable energy, losses, reserve, peak as a pass/fail gate
- Published methodologyRevision log“What changed, and when?”Every rule change, catalog status change and correction, with its date and its reason.Dated entries · corrections recorded, not overwritten
What is not here: no installed system quotes, no solar-plus-storage design service, no lead capture, no prices and no product recommendation outside an evidence-gated verdict. The installed-backup page is an editorial next-step guide only.