Magnetic charging makes attaching a battery easy, but it doesn’t guarantee that the battery will fit your phone’s shape. Apple’s folding iPhone Duo introduces a shorter body that gives accessories less room to stretch. BMX’s SolidSafe Duo responds with a compact, 5,000mAh power bank designed around those proportions, bringing a rotating stand, color display, and attached USB-C cable along for the ride.
The difference starts inside, where a custom-shaped battery cell lets the enclosure follow the Duo’s footprint instead of extending beyond its edges. The black, CNC-machined aluminum housing has rounded corners and a broad face that sits below the cameras. That gives the accessory a more deliberate relationship with the phone, although matching its outline doesn’t make the added thickness disappear, of course.
Designer: BMX (Better Mobile Experience)
A circular ring folds out from the back and rotates 360°, giving the phone support in portrait or landscape orientation. Reading a recipe on the counter could give way to watching a video over lunch without detaching the battery. The stand makes particular sense for an unfolded screen, which offers more room to watch but also more phone to hold in your hand.
Nestled inside that ring is a full-color display showing the power bank’s remaining charge and live charging wattage. The distinction matters because the percentage belongs to the accessory, not your iPhone. It also gives you a way to check both your reserve and the current power output, rather than assuming that an attached battery is always charging at its advertised maximum speed.
The attached USB-C cable doubles as a lanyard, so wired charging doesn’t begin with a search through your bag. Plug it into a compatible device for up to 20W output, or use it to refill the power bank at up to 15W. It’s a simple detail, but it keeps the wired option available even when the rest of your charging gear is elsewhere.
Wireless charging, meanwhile, tops out at a claimed 15W, below the iPhone Duo’s supported 25W maximum. You’re getting a tailored shape rather than the phone’s fastest wireless charging. Connecting two devices also changes the numbers, splitting output between 10W over USB-C and 5W wirelessly. That could help another device through the afternoon, but neither connection retains its single-device maximum in that arrangement.
The SolidSafe name also needs a little unpacking. BMX uses semi-solid-state cells and says their reduced liquid electrolyte content helps lower fire risk compared with conventional lithium-ion batteries. That’s a reduced-risk claim, not a promise that the battery can’t fail. The rigid aluminum enclosure also helps dissipate heat, according to BMX, rather than preventing the pack from becoming warm while it charges your phone.
Available for $79.99 in the US, SolidSafe Duo adds about 0.43 inch of thickness and 4.47 ounces to your phone. Those numbers deserve as much attention as its compact outline, particularly when the phone itself already folds shut. Having a stand and cable built into the battery means fewer loose accessories to pack, but a thicker stack to slide back into your pocket.
