Most counterfeits waste your money. A counterfeit car seat gambles with the one passenger who cannot choose, in the one crash nobody schedules. Fake and non compliant child seats have been found on marketplace and discount channels repeatedly, dressed in the colours and logos of brands parents trust, built without the testing, materials, or energy management that make the real thing boring in a collision.
This is not a category for bargain instincts. It is a category for provenance, and the checks below are the ones safety organisations and manufacturers themselves publish, in plain form.
A power station's capacity in watt hours is bounded by its cells, and cells have a known weight and cost. A unit claiming high capacity at a suspiciously low weight or price is mislabelled, tested at a flattering point, or both. A simple timed load test with a known appliance reveals the delivered capacity closely enough to judge any claim.
Lithium cells store a fairly predictable amount of energy per kilogram. That single fact audits most listings: divide the claimed watt hours by the unit's weight and compare with what real products from established makers achieve. Modest differences come from casing and electronics. A claim that implies half again the energy density of every reputable unit on the market is not a breakthrough; it is a label.
Price tells the same story in another unit. Cells are the dominant cost, so a station claiming the capacity of a unit that sells for two or three times more has to have saved the money somewhere: fewer cells, lower grade cells, or a rating measured in a way no user will ever reproduce, such as quoting cell capacity before conversion losses that every real output passes through.
Charge the unit fully, then run a steady, known load, a lamp or heater with a stated wattage, ideally through a cheap plug in energy meter, and record what it delivers before shutting down. Delivered energy will legitimately fall short of the headline figure, because conversion from battery to AC output loses roughly a tenth or more. A unit delivering half its claim is not showing conversion loss; it is showing its real capacity.
Check charge time against the claim as well. A genuinely large battery cannot refill in an implausibly short time at the charger's stated wattage; the numbers have to reconcile. While it runs, note heat and fan behaviour under a moderate load. Units built around overstated cells often run hot and throttle early, because the marketing capacity and the hardware's comfortable capacity were never the same number.
Weight, price, and claim should form a consistent triangle with established products; when one corner is wildly out of line, walk away regardless of reviews, since reviews for these listings are part of the packaging. Prefer makers who state both cell capacity and expected AC output, because that honesty about losses is a reliable character signal in this category.
Keep the packaging and run the load test inside the return window. A power station is bought for the day everything else fails, and that is the worst possible moment to discover the capacity was a rumour. Thirty minutes of testing on a quiet afternoon is the entire price of knowing.
Keep reading: Who we protect covers a nearby case in this series.
Expect roughly ten to twenty percent below the headline watt hours on AC output, due to conversion losses. That gap is normal. A unit delivering around half its rating is mislabelled, not inefficient.
It is a strong check. Lithium cells have a predictable energy per kilogram, so a unit claiming far more watt hours per kilo than reputable products achieve is claiming something its cells cannot contain.
Fully charge the unit, run a steady appliance of known wattage, ideally measured with a plug in energy meter, and time it to shutdown. Multiply out the delivered energy and compare it with the claim, allowing for conversion losses.
Because most buyers never measure output; the unit lights lamps and charges phones, and satisfaction is recorded before the shortfall matters. Reviews measure first impressions, not watt hours, which is why the arithmetic checks matter.