CIO Adds a Black Model to the SMARTCOBY ULTRA SLIM 3K, One of the World's Thinnest Power Banks

CIO Co., Ltd. released a black version of the SMARTCOBY ULTRA SLIM 3K, a power bank it bills as one of the world's thinnest at 4.98mm, on April 24, 2026^[1]. It is priced at 8,980 yen including tax^[1]. The product pairs an ultra-thin design that stays unobtrusive even when stacked on the back of a smartphone with MagSafe-compatible wireless charging and support for Apple's Find My. It is the second color option, following the silver model already on sale.

A 4.98mm, Roughly 82g Ultra-Thin Body

The standout feature is an extremely thin and light design measuring 4.98mm thick and weighing about 82g^[1]. CIO says it barely protrudes when attached to the back of an iPhone, and is thin enough that you forget you are carrying it^[1]. Because typical power banks are bulky and thick, a form factor that can be integrated with a smartphone is a practical touch for everyday carry.

The maker addresses the strength trade-off that usually comes with thinning a device through its housing material. The body uses 0.3mm-thick high-strength stainless steel, which CIO says secures enough rigidity to protect the internals from bending and impact despite the slim profile^[1]. The surface has a matte finish and the sides are mirror-polished, and PVD treatment plus an anti-fingerprint coating are applied to preserve its appearance over time^[1]. The product also has a track record on the crowdfunding service Makuake, where its project drew support from more than 3,800 backers^[1].

MagSafe Wireless Charging and a 3,000mAh Capacity

For charging, the device supports MagSafe-compatible Qi wireless charging^[1]. Simply attaching it to a MagSafe-equipped iPhone starts 7.5W wireless charging automatically, with no need to plug and unplug a cable^[1]. Connecting a USB-C cable also enables 10W wired charging, and the unit supports pass-through charging that powers a connected device while the battery itself charges^[1][2].

The capacity is 3,000mAh^[1]. CIO frames this figure not as a push toward higher capacity at the cost of added weight, but as a right-sized capacity meant to lightly cover those "just a little short" moments^[1]. As a guide, wireless charging delivers roughly 0.4 charges for an iPhone 16, 0.5 for an iPhone 15, and 0.55 for an iPhone Air^[1]. Rather than a battery that covers a full day, it is designed as a backup for use on the go.

Apple's Find My Support Helps Prevent Loss

The smaller a power bank is, the easier it is to leave behind. As a countermeasure, this product builds in an anti-loss tag compatible with Apple's Find My^[1]. You can check its location, receive notifications, and track it by playing a sound from an iPhone, so keeping it in a bag helps prevent leaving it behind^[1].

A notable point is that the Find My function keeps working for about two months even after the battery is fully drained^[1]. Because power for Find My is replenished each time the unit is recharged, the tracking function can be maintained without worrying about the remaining charge^[1]. Note, however, that the product contains a magnet, so credit cards and IC cards should not be placed near it or sandwiched against it^[1]. Using the Find My function also requires pairing setup in advance^[1].

Summary

The SMARTCOBY ULTRA SLIM 3K is a slim power bank built around its 4.98mm thickness and roughly 82g weight, combining MagSafe-compatible wireless charging with Apple's Find My support. The new black option means it can now be chosen in two colors alongside the silver model launched in January 2026. Its 3,000mAh capacity is modest, but as a backup battery carried stacked on a smartphone, it suits anyone who wants to prioritize thinness above all.

Source: https://prtimes.jp/main/html/rd/p/000000642.000043212.html

Source: https://connectinternationalone.co.jp/cioproduct/mobilebattery/smartcoby/cio-mb10w1c-3k-uswl7/