How we choose

Straight answer first: we don’t physically test the products on this site. We research them. Here’s exactly how, so you can judge our picks for yourself.

Where our information comes from

• Manufacturer specifications — capacity (Wh), continuous and surge output, UPS switchover time, recharge time, weight and battery chemistry, checked against the Amazon UK listing.
• Live UK prices — every price button is pulled from Amazon’s own product API and refreshed through the day. We keep an hourly price history, so we can tell a real discount from a normal price.
• Owner reviews and support reputation — we read what UK buyers report about reliability, app quality and after-sales support, and weigh recurring complaints.
• UK-specific needs — UK plugs, UK power cut patterns and the devices people actually need to keep running: routers, fridges, phones, medical kit.

How runtimes are worked out

Runtime figures on this site are calculated estimates, not measurements. We use:

Runtime (hours) ≈ battery Wh × 0.85 ÷ device watts

The 0.85 allows for inverter losses. Real results vary with temperature, battery age, and how much your device actually draws — a fridge cycles on and off, for example, so it usually lasts longer than a flat-rate estimate.

How we pick and rank

• A product has to be sold on Amazon UK and currently available — our system checks this automatically and flags listings that disappear.
• We rank on how well the specs fit a use (a power cut, a campervan, a garden office), then on value at today’s price.
• When a product is replaced by a newer model, we update the page and say what changed.

How we’re paid

When you buy through our links, Amazon pays us a small commission at no extra cost to you. No brand pays to appear on this site, and commission rates don’t decide what we recommend.

Spotted a mistake?

Specs change and listings get swapped. If something on a page is wrong, tell us and we’ll fix it.