About Gadget Crunchie

Who's behind the site

I'm Zubair Abid, a web developer from Pakistan and the founder of MZA Dev. I build websites and web tools for businesses. I have been building websites since 2019. Gadget Crunchie is where I use the same skills to turn confusing battery and power questions into clear, checkable answers.

The site started with a problem I deal with at home. In Pakistan, scheduled power cuts (load-shedding) are part of daily life, and every household asks the same questions: how long will this UPS battery last, is a bigger battery worth it, should we add solar, which charger is enough? When I looked for answers, I found two kinds of pages: sales pages pushing one product, and calculators that assumed perfect efficiency and gave numbers nobody sees in real life.

So I built calculators that use realistic assumptions, show their working and warn you about the things that catch people out: lead-acid batteries that shouldn't be drained past half, fridges that need two to three times their running power just to start, and power banks that deliver roughly two-thirds of their rated capacity.

What you'll find here

The calculators cover four kinds of question. Batteries and runtime: how long a power station, power bank or UPS battery will keep your devices running. Charging: how long a battery takes to refill, whether a charger is strong enough, and whether a power bank is allowed on a plane. Home energy: what an appliance costs to run and how big a solar system needs to be. Screens: how sharp a monitor, laptop or TV really is.

The tools are built for people in the US, the UK, Pakistan and anywhere else. Energy units are the same everywhere, and where money or local rules come in, you enter your own price per unit, your own currency and your own battery voltage.

Every calculator page follows the same layout: a short answer at the top, the tool itself, the formula with a worked example, the mistakes people usually make and a list of common questions. Once you've used one, you know where to find everything on the others.

How the numbers are kept honest

• Formulas first. Every tool publishes its formula and a worked example, so you can check the result with a phone calculator in under a minute.
• Realistic defaults. Efficiency, reserve and usable-capacity values are set to typical real-world figures, not best-case marketing claims.
• Labelled estimates. Typical device wattages are shown as ranges and marked as typical. Specific product specs are only listed after checking them against the manufacturer's published data.
• Your data stays with you. The calculators run in your browser. Nothing you type is sent to or stored on a server.
• Dated updates. Each page shows when it was last reviewed. When rules change, such as airline battery limits, the page is updated and re-dated.

The full list of assumptions and where they come from is on the how we calculate page.

How the site is funded

Gadget Crunchie is free to use and supported by advertising. Some pages may later include affiliate links to products; if they do, it will be disclosed on the page, and it will never change a calculation. No manufacturer or shop pays to be featured or to influence results.

Get in touch

Found an error, want a calculator that doesn't exist yet, or have a question about a result? Use the contact page. Corrections are the most useful messages I get, and they're fixed quickly.

If you need a website, web app or a custom calculator for your own business, that's what I do at MZA Dev.