About Power Bank Tools

What this site is

Power Bank Tools answers three kinds of question: how much energy a battery holds, how many times one battery can charge another, and whether the charger and plug you own will work where you are going. Every tool states the formula it used, the assumptions behind it and the point at which it stops being able to answer.

What it deliberately does not do

• It does not predict charging speed, full-charge times or real-world runtime.
• It does not certify electrical safety, and nothing here is a substitute for a manufacturer's documentation.
• It does not rank products. There is no "best charger" list and no score out of ten.
• It does not publish product recalls as a service. Where a recall matters, check the manufacturer directly.
• It does not guess. When the data needed for an answer is missing, the answer is "needs verification" rather than a plausible number.

How the site is funded

Some links to products may earn a commission if a purchase follows. That has no influence on the calculations, which run on your device from published formulas, and no influence on which products appear. No affiliate programme is assumed to be in place: where no approved link exists, the site uses a plain reference link and says so. See the affiliate disclosure.

Independence

This site is not affiliated with, endorsed by or authorised by any charger or power bank manufacturer, including brands named in explanations or examples. Brand names appear only where they are necessary to describe a device category or a specification problem.

Who writes it

The site is maintained by a single editor. Methods and sources are recorded per page; the rules behind the calculators are published in how we calculate, and the standards applied to content are in the editorial policy.

Where to start

• Power bank calculator — estimated charges from a pack.
• mAh to Wh converter — read the label correctly.
• Travel adapter finder — socket shape and voltage together.

Last reviewed 6 November 2026.