The Mophie Hold Force Powerstation Plus Mini is a large-capacity battery pack (4,000mAh) that boasts its own built in Lightning (and MicroUSB) connector. It connects to your iPhone 7 magnetically, although this does require a special iPhone case (the Mophie Hold Force Base Case, available for both iPhone 7 and iPhone 7 Plus). Mophie claims that the 4,000mAh battery pack will boost your iPhone 7’s battery life by an extra 12 hours, and this beats all the other actual battery cases available for the iPhone 7. See: Best battery case for iPhone 7. It’s not a case in itself so it won’t weigh down or bulk up your iPhone while you’re not using it. Of course, the downside to that is that you have to carry it around with you, presumably away from the phone itself. While the magnetic fit is reasonably strong, it’s not enough to keep it securely attached while going in and out of a pocket or bag. Once connected, the Powerstation battery’s internal power management uses smart charging circuitry to communicate with the iPhone to determine the correct amount of power required for a safe, quick charge. Push the status button to check the charging status and current battery life of the case. So far so good, but the system is not as handy as a proper battery case. While in place the Powerstation covers the iPhone’s rear camera so it will remove some functionality while attached. You don’t get that with a battery case, as Mophie knows well. While the magnetic attachment is a neat idea we wonder whether just buying one of Mophie’s non-magnetic Powerstation battery packs (which don’t require the dedicated case) would make more sense. The Mophie integrated series of Powerstation battery packs feature the built-in Lightning/MicroUSB connector, and come in 4,000mAh (£59.95/$59.95), 6,000mAh (£79.95/$79.95), and 12,000mAh (£99.95/$99.95). If you don’t mind carrying round a cable with you, for £49.95/$49.95 you could pop the 6,000mAh Mophie Powerstation or smaller, lighter 3,000mAh Powerstation Mini (£29.95/$29.95) in your bag. The Mophie Hold Force Powerstation Plus Mini only really makes sense as part of the modular Hold Force family of add-on products. You need the Powerstation itself (£59.95/$59.95/€69.95) plus the Base Case (£34.95/$39.95/€39.95). The case is available in a range of ten colours – Black, Coral, Mint, Navy, Stone, Black Gradient, Gold Gradient, Rose Gold Gradient, Navy gradient, and Silver Gradient – but is mostly transparent polycarbonate. Also available are the Hold Force Folio and Hold Force wallet; both also available in various colours (Black/Grey, Stone/Grey, and Navy/Orange). The Hold Force Folio (£14.95/$19.95/€19.95) magnetically attaches to the Base Case, and can hold three credit cards, cash or ID. It also wraps round the iPhone, protecting its screen, and can be used as a stand. The simpler Hold Force Wallet (£14.95/$19.95/€19.95) also attaches magnetically to the Base Case, and can hold two credit cards, cash or ID. We’re not sure you’d pick either the Wallet or Folio over a dedicated card-carrying iPhone 7 case, but they do make sense if the magnetic Powerstation appeals to you, although you’ll have to remove them to affix the battery pack. All in all it’s a nice idea but a bit fiddly. Simon was Editor of Macworld from the dark days of 1995 to the triumphant return of Steve Jobs and the launch of the iPhone. His desk is a test bench for tech accessories, from USB-C and Thunderbolt docks to chargers, batteries, Powerline adaptors and Fitbits.