Independent analysis of third-party test data · est. 2026

The box says 1,070 watt-hours. The lab says 910.

Rated capacity is a marketing number. Usable capacity is the one that keeps your fridge cold. We collect the published bench measurements, put both figures side by side, and show every source.

How we rate → Start with your use case →

Data status● Current

11Units covered

10With lab-measured capacity

0Sponsored placements

SOURCES LAST CHECKED 5 SEP 2026 · 38 CITED WORKS

The premise

We haven't run our own bench yet — so we don't pretend to. Every measurement here is somebody else's published test, named and linked, and every runtime is arithmetic we show you.

The Solar Power Auditor desk Research-led analysis · no manufacturer relationships

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How every unit is scored

Usable capacity & output 30%

Recharge & solar input 20%

Build, ports & durability 20%

Portability & noise 15%

Value per usable Wh 15%

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The two pages most people need

Roundup The Best Power Stations for Home Backup (2026) — What Actually Keeps a Fridge Cold Home backup is a question of hours, not watt-hours. The EcoFlow Delta Pro 3 wins on 3,790 measured usable watt-hours and genuine 240 V output. Full calculated runtimes and every source. Updated 5 September 2026 · 7 min Review EcoFlow Delta Pro 3 Review — 93% Measured, and the Only 240 V Unit Anyone Has Tested The EcoFlow Delta Pro 3 returned 3,790 of 4,096 rated watt-hours in independent testing — 93%, the highest measured efficiency on this site — with native 120 V and 240 V split-phase output. Updated 5 September 2026 · 6 min

Start with the job you need done

10 use cases · each with a pick

Off-grid living Sizing, chemistry and solar maths Home blackout Whole-home and fridge-only picks Car camping Carry weight against nights of fridge Van & RV Recharge on the move CPAP overnight Nights per charge, calculated Under $700 Cost per usable watt-hour Running a fridge What 1 kWh really buys Sizing a system Load math, no guessing Rated vs usable Why the box overstates it Which brand Four brands, one table

Reviews & comparisons

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Roundup The Best Budget Power Stations Under $700 (2026) — Cost Per Usable Watt-Hour Cheap is not the same as good value. Ranked on list price divided by independently measured usable capacity, the Bluetti AC70 is cheapest per watt-hour and the Anker SOLIX C1000 Gen 2 is the best buy. Review EcoFlow River 2 Pro Review — The Lightest Unit Here, and the Least Efficient The EcoFlow River 2 Pro weighs 18.4 lb and recharges in a measured 1 h 18. It also returned just 81% of its rated capacity, the weakest efficiency of any unit we cover. Roundup The Best Power Stations for Camping (2026) — Ranked on Watt-Hours Per Pound For camping the number that matters is usable watt-hours per pound of carry weight. The Jackery Explorer 1000 v2 leads at 37.3, with full measured weights and calculated fridge runtimes. Roundup The Best Power Stations for a CPAP (2026) — Nights Per Charge, Calculated A CPAP draws about 35 W with the humidifier off and roughly double with it on. Here is how many nights each power station actually delivers, calculated from independently measured capacity. Roundup The Best Power Stations for Vans and RVs (2026) — Two Nights and a Way to Refill Van and RV power is about capacity you can recharge while moving. The Jackery Explorer 2000 v2 leads on 1,710 measured usable watt-hours at the best weight ratio here, with full comparisons. Roundup The Best Power Stations for Home Backup (2026) — What Actually Keeps a Fridge Cold Home backup is a question of hours, not watt-hours. The EcoFlow Delta Pro 3 wins on 3,790 measured usable watt-hours and genuine 240 V output. Full calculated runtimes and every source.

Guides & load math

All guides →

Guide Generator vs Battery for Home Backup — Fuel, Noise, Permits and Total Cost A generator runs indefinitely but needs fuel, ventilation and maintenance. A battery is silent and safe indoors but finite. Here is the honest comparison, including the case for owning both. Guide Running a Fridge Through a Power Outage — What Each Battery Size Actually Buys How many hours of refrigeration each class of power station delivers, calculated from independently measured capacity, plus the food-safety window that decides whether you need a battery at all. Guide How to Size a Power Station — Load Math for a Fridge, a CPAP and a Camp Kitchen Work out the watt-hours you actually need in five steps, with typical appliance draws, the efficiency correction almost everyone forgets, and a worked example carried through to a real unit. Guide LiFePO4 vs NMC — Which Battery Chemistry Should Your Power Station Use? LiFePO4 lasts four to eight times longer and is far harder to set on fire. NMC is lighter. For a power station the answer is almost always LiFePO4 — here is why, and the number that actually matters. Guide Rated vs Usable Capacity — Why Your Power Station Gives Back Less Than the Box Says Every portable power station delivers less energy than its rating. Independent testing puts the loss between 7% and 25%. Here is where it goes, how to work out your real number, and which units keep the most. Guide Solar Recharge in Practice — Why a 100 W Panel Does Not Give You 100 Watts A 100 W panel was independently measured averaging 50.7 W in full sun. Here is where the rest goes, how to plan around it, and the input ceiling that silently wastes half of some arrays.

Independent power-station analysis for real budgets

Portable power is a category where the number on the box and the number you get differ by 7% on a good unit and 25% on a bad one. Independent labs measure that gap; manufacturers rarely publish it. This site's whole job is to put those two figures next to each other, for every unit worth considering, with the source named.

We cover EcoFlow, Jackery, Bluetti and Anker SOLIX because that is what the US market actually buys.

Standing policy

＋Cite a named third-party laboratory for every measured figure

＋Publish the arithmetic behind every runtime we calculate

＋Say plainly when nobody has measured something

＋Show manufacturer claims and independent measurements as separate things

−Claim to have tested hardware we have not tested

−Accept sponsored placements, paid scores or free units

−Run display advertising anywhere on the site

−Quote a street price we have not checked

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