How we choose products

This page explains how we choose the products in our guides and how we rank them. It is the method behind every verdict on the site. We publish it because you should be able to judge our guides for yourself.

In short, we choose from published specifications. We read manufacturers' UK product pages, standards and official guidance. We then compare the figures that matter for each product category.

For product facts we use the manufacturer's own UK product page, such as the capacity, output, battery chemistry and warranty it lists. For standards we use the publisher. For example, IP ratings come from IEC 60529, the standard that defines the IP Code.

For official guidance we use regulators. Ofgem covers smart meters, and the Civil Aviation Authority sets the rules for power banks on aircraft. For solar yield in Britain we use PVGIS, the free estimator from the EU Joint Research Centre.

Each guide ends with a Sources section that lists every page we used. If a source changes, the guide may be out of date, which is why each page shows the date it last changed.

We do not physically test products. We have no lab, no test rig and no measurements of our own. Every figure in a guide is therefore either a published claim, which we attribute, or a simple sum that we show.

We do not take payments. We don't use affiliate or sponsored links and we don't run ads, so we earn nothing from the products we mention. Our picks are chosen on published specifications, not payments. We also give no star ratings, because a score would suggest testing we have not done.

We do not name a reviewer. No single person stands behind a verdict, and we will not invent one, since that would mislead you. Accountability sits with the sources we cite and with our corrections process below.

Our guides rank picks by role, such as best all-rounder, best for camping or best for home backup. A role ties a pick to the figures that matter for that job. For a power station, those are usable capacity, output in watts, battery chemistry and its stated cycle life, charge speed, expansion options and warranty.

For solar chargers we weigh panel watts above battery size, because panel area decides how much energy you gather. For garden lights we weigh the IP code, panel placement, battery access and light colour. For energy monitors we weigh the supply type, such as single-phase, and the safety of fitting.

Because manufacturers state cycle life and charge times under their own conditions, we say so where a figure is a manufacturer claim. Where two brands state figures on different bases, such as cycles to 80% against cycles with no stated end point, we say they do not compare directly.

Prices on UK stores change often, and several listings we read showed large reductions from a crossed-out list price. So we do not quote prices unless we can source them, and we label any price as the price at the time of writing.

We also give no pounds-a-year savings figures unless two independent primary sources support them. Instead, we show the arithmetic so you can use your own tariff.

We update a page when we change its content, and the page shows that date as Last updated. We do not currently follow a fixed review schedule, and we do not claim to re-check every figure every month.

Because listings change, always check the manufacturer's current page before you buy. The sources list on each guide takes you straight there.

If you spot a wrong or out-of-date figure, tell us through the contact form. We check the source, fix the page if we find an error, and update the date. We would rather correct a mistake in public than leave it standing, because readers rely on the page.