How We Test
Most power bank reviews are written by someone who charged their phone once and read the Amazon spec page. These are not those reviews.
Who is behind these reviews
I started doing this because I like gadgets. Specifically, I like finding things that genuinely make life easier, cut out unnecessary effort, or just work better than whatever I was using before. I research purchases properly before I buy, and I tend to go deep. Over time, friends and colleagues kept asking where I got particular things. That charger. That power bank. That cable that actually stays seated. It happened often enough that I thought I might as well write it down somewhere useful.
That is how SmartGadgetKit started. Not as a business plan, but as a recommendation habit that outgrew my notes app.
Alan is a network engineer with nine years of experience in infrastructure and connectivity. He understands power delivery, USB-C protocols, and charging efficiency at a level most reviewers do not get near. When a spec sheet says 65W and the port delivers 58W under load, he can measure it and explain why. When a manufacturer’s claim does not add up, he can say so plainly.
Darleene is a nurse based in Singapore. She works 12-hour shifts and tests compact, portable gear in the conditions it was built for: on her feet, away from a plug, no time to fuss. She is not a gadget enthusiast. She is a practical person who needs her phone alive from the start of a shift to the end of it, and she knows better than most whether something genuinely fits in a pocket.
Neither of us is a professional reviewer writing from a press loan. We buy or borrow the kit, use it in real life, and write what we find.
How we score products
Every product on SGK is scored out of 10 using a weighted criteria system. The weighting varies slightly by product type, because what matters for a pocket power bank is not the same as what matters for a GaN wall charger. But the principle is consistent: each final score reflects multiple criteria, not a single impression.
For power banks, the criteria and their weights are:
- Charging Speed: 30%
- Carry Rating (portability): 25%
- Value for Money: 20%
- Build Quality: 15%
- Compatibility: 10%
A product that charges quickly but is too large to carry on a flight scores well on speed and poorly on portability. That tension shows in the final number, and we explain it in the review. A score without context is not useful to anyone.
How we choose what we review
We look for products that are readily available to buy in the UK, solve a real problem for a real person, and fit within SGK’s core categories: power banks, GaN chargers, and USB-C cables and accessories. We are not sent products by manufacturers in exchange for coverage. We buy or borrow what we test.
If a product is from a brand we have not covered before, we check independently that it is a legitimate, purchasable product before writing about it. If we cannot verify it, we do not review it.
What we actually test
Charge times to real devices
We time full charges to named, specific devices under real conditions: MacBook Pro 14-inch, iPhone 15, iPad Pro. Not “a phone” or “a laptop.” The specific devices matter because charge times vary significantly between them, and vague descriptions let manufacturers off the hook.
Bank recharge time
We also time how long the power bank itself takes to recharge from empty. This matters as much as output speed. A bank that takes eight hours to recharge is a problem if you need it topped up overnight. We note the charger wattage used, since this affects the result.
Port output under load
Alan measures what actually comes out of each port while a device is drawing power. The figure on the box is the ceiling, not the guarantee. Most of the time there is a gap between rated and real-world output. We say what it is, and for high-wattage products Alan explains whether it matters in practice.
Multi-port simultaneous output
Where a power bank has more than one port, we test what happens to output when both are in use at the same time. Total wattage is shared across ports, and how that sharing is managed varies significantly between products. A bank that claims 87W total but drops to 45W on the main port when a second device is connected is a different product from one that holds its output. We say which it is.
Pass-through charging
Some power banks support charging themselves and a connected device simultaneously. We test this where it is listed as a feature. Products that support pass-through often run warmer in this mode and sometimes throttle output. We note both.
Trickle and low-current mode
Small devices like earbuds and smartwatches draw very low current. Some power banks auto-shutoff when they detect a low draw, which means they cannot charge these devices at all. We check whether a bank supports low-current mode and flag it if it does not. For anyone who wants to charge a pair of wireless earbuds on a long flight, this matters.
Heat under sustained load
We note whether a unit gets uncomfortably warm during extended charging. We do not have thermal imaging equipment, but sustained heat that is noticeable to the touch is a signal worth recording. A unit that runs warm under normal use is also more likely to throttle output as a safety measure.
LED and display accuracy
Many power banks display remaining capacity as a percentage or a set of LED dots. We check whether these indicators roughly match real remaining capacity. A bank that shows three out of four LEDs and then dies minutes later is a usability problem the spec sheet will not mention.
Airline carry-on compliance
The UK CAA limit is 100Wh for carry-on without airline approval, up to 160Wh with it. We verify the actual Wh rating of every power bank we test and tell you clearly whether it qualifies. Manufacturer listings are not always consistent on this, and getting it wrong at the gate is an expensive mistake.
Physical dimensions
We measure the unit ourselves. Stated dimensions in product listings are not always accurate. A few millimetres can be the difference between something fitting in a bag pocket and not, so we measure rather than trust.
Build quality over time
First impressions are easy. We carry gear for weeks, not just days, and note whether finishes hold up, seams stay tight, and ports stay clean. Soft-touch coatings that look good in week one sometimes tell a different story in week four. We say so when they do.
Cable compatibility and protocol support
Where relevant, Alan tests USB-C Power Delivery and PPS negotiation. This matters most for fast charging. A charger that supports PPS can deliver exactly the voltage a device needs, rather than stepping between fixed voltages. The difference is real charging speed in the real world. We note when a product supports it and when it does not.
For GaN wall chargers, the methodology shifts toward thermal performance under load, multi-port output when both ports are in use simultaneously, and compatibility with specific laptop charging standards.
What we can’t measure, and where we get that data
We do not have lab equipment. We cannot produce efficiency curves to two decimal places or run controlled thermal imaging. When that level of precision is relevant, we say so and cite the source.
Charge-Test is one independent testing source we reference. When their figures appear in a review, they are attributed clearly as “independent testing by Charge-Test confirmed…” rather than presented as Alan’s own measurements.
The distinction always matters. If Alan timed it himself, you read “I timed this at…” If the figure came from an independent source, you read “independent testing by X found…” You can always tell which is which. That is intentional.
Products we haven’t personally tested
Some reviews are built from manufacturer specifications cross-referenced against independent sources, rather than from direct personal testing. This is not ideal. When it is the case, we say so in the review. We do not present sourced data as personal experience, and we do not fabricate test results.
If you see attribution language in a review, that is why it is there. It is not a weakness we are trying to dress up. It is the honest version of what we know.
Keeping content current
A review published in 2024 may not reflect a product that has since been superseded or discontinued. We update content when the product changes significantly, when new independent data is available, or when we have tested something further ourselves. The date shown on every post reflects the last time the content was reviewed, not just when it was first published.
A note on affiliate links
SGK uses affiliate links. If you buy something through a link on this site, we may earn a small commission from the retailer. That is how the site funds itself. It does not change what we write.
We form our view of a product before the affiliate link is added. No product receives a better score because it earns a higher commission. The two things are kept separate, and that is not just policy. It is how we would want any site we read to work.
