Besiter Mercury 10A Lightning power bank at a glance:

Mobile phones and tablets have become useful camera accessories, but they are of no help if the power runs out at a critical moment. Because of this, power banks are something of a must-have to keep your devices alive when you’re out in the field for any length of time. They can also be used to recharge an increasing number of camera batteries in situ.

On the whole, power banks tend to be functional devices with few distinguishing features. However, the Besiter Mercury series is a bit different. The slimline, curvy cases consciously echo the design of high-end smartphones, and the model we’re looking at here also claims to be the world’s first MFI-certified power bank. In short, this means that it charges using an Apple Lightning cable, which is convenient for iPhone and iPad owners. A micro USB version is also available for Android users. It comes in two colour options – black or white – and two different capacities. I think the 10,000mAh version at £34.99 looks better value than the 5,000mAh model that costs £28.99.

Two USB outputs are used for charging external devices, with one offering 1A output and the other 2A for faster charging of power- hungry devices like tablets. A small button on the side turns charging on and off, and shows the power bank’s own current charge status using a row of four (very subtle) LEDs.

Besiter also suggests that the Mercury is capable of pass-through charging, so that both it and connected devices can be replenished using a single USB socket when connected together; however I couldn’t get this to work. Nonetheless, the flat design means it’s easy to carry around and can sit in a pocket back-to-back with a phone for charging, which doesn’t work with more boxy rivals. The capacity is also ample to keep your phone going for several days.

Besiter-Mercury-10A-Lightning-power-bank-attached-to-phone

SCORE: 4 out of 5