BMX is moving quickly to stake out territory around Apple’s foldable iPhone, unveiling the SolidSafe Duo, a compact 5,000mAh magnetic power bank designed specifically around the dimensions and usage patterns of the new folding form factor.
Rather than simply shrinking an existing magnetic battery pack, Better Mobile Xperience says it developed a custom semi-solid-state cell that allows the SolidSafe Duo to measure 77 x 88 x 11mm. The idea is straightforward: keep the accessory within the edges of the phone instead of leaving an awkward battery pack protruding from the back.
That becomes particularly important on a foldable device, where accessories designed around conventional slab phones could interfere with how the handset is held, positioned or partially folded.
BMX has also built a 360-degree rotating ring stand into the power bank. It can prop the iPhone Duo up vertically, horizontally or in partially folded positions while remaining magnetically attached and charging. That could make the stand more useful for video calls and media viewing than the fixed kickstands found on many existing magnetic power banks.
Charging reaches up to 15W wirelessly, while the integrated USB-C lanyard cable can provide up to 20W wired output. When using wired and wireless charging simultaneously, output is rated at 10W and 5W respectively. The same attached USB-C cable accepts up to 15W when recharging the power bank.
There’s also a full-colour TFT LCD displaying remaining battery capacity and live charging wattage, while the electronics and battery are enclosed inside a CNC-machined aluminium housing. At 5,000mAh, this is still firmly a portable top-up battery rather than something intended to replace a larger high-capacity power bank.
The more interesting part is the battery technology. BMX describes its custom cell as semi-solid-state, using significantly less liquid electrolyte than conventional lithium-ion batteries. The company argues that reducing the amount of flammable liquid electrolyte can help lower risks associated with heat, physical damage and internal short circuits.
That shouldn’t be confused with the fully solid-state batteries frequently discussed as a future step for electric vehicles and consumer electronics. “Semi-solid-state” covers an intermediate approach, and BMX hasn’t provided detailed cell chemistry, energy-density figures or independent safety testing alongside the announcement. Those details would be useful for assessing how significant the technology is beyond enabling this particular shape.
The SolidSafe Duo is priced at $79.99 in the US and £79.99 in the UK. BMX says global availability begins in September, with Amazon availability expected from October 2026.
Foldable phones create an unusually interesting challenge for accessory makers because cases, stands, chargers and batteries can no longer assume a permanently flat device. If Apple’s foldable iPhone establishes another significant hardware category, the SolidSafe Duo is unlikely to remain unusual for long.
