N6-RB REPLACEABLE 21700 BATTERY POWER BANK — 22.5W FAST CHARGING · 55G ULTRA LIGHT
About KangTao Smart

POWER THAT
EVOLVES.

Portable power with more choice, thoughtful design, and a personality of its own. KangTao Smart creates modular charging products for everyday carry — practical to use, enjoyable to hold, and designed with their continued use in mind. With N6-RB, that belief takes shape around a replaceable battery.

01 / THE QUESTION

A Small Question.
A Different Direction.

A charging device finds its way into the ordinary moments of your life. It comes along on your commute, sits beside your phone at a café, and stays in your bag when the day runs longer than expected.

Over time, its battery can lose capacity while the rest of the device still works. We saw an opportunity to make battery replacement part of the design.

The question was simple: how could a portable charging device remain useful when its battery needed changing? For KangTao Smart, the answer begins with giving the battery its own accessible place.

N6-RB early concept sketch
N6-RB structure exploration sketch
02 / THE SKETCHES

An Idea Takes Shape.

The N6-RB concept brings the battery compartment, opening mechanism, and circular ring into one compact form.

Our sketches explore how these elements can work together: where the cell sits, how the housing opens, and how the device feels in the hand. Angular lines and textured details give the design its mechanical character, while the layout keeps everyday interactions at the center.

The aim is to make the structure useful and the experience intuitive, with a shape that feels distinctive enough to become part of your personal carry.

N6-RB uncolored housing prototypes
03 / THE MODELS

From Paper to Something You Can Hold.

Physical models bring a different perspective to a design.

The uncolored housing pieces turn lines and proportions into something tangible. They make it possible to consider how the parts meet, where the fingers rest, and how the ring relates to the body of the device.

These small relationships matter. A compact product has to make room for its components while remaining comfortable to handle. Bringing the design into three dimensions makes those choices concrete.

N6-RB circuit boards and connector assemblies
04 / THE ELECTRONICS

Thought Through, Inside and Out.

Inside N6-RB, the charging electronics share a compact space with the replaceable battery structure.

The circuit boards and connector assemblies reveal the less visible side of the product. Their arrangement has to work with the housing, the charging connections, and the space needed to access the cell.

We consider these elements together. The outside gives the product its character; the internal layout supports what it needs to do. Both belong to the same design.

N6-RB replaceable 21700 cell swap
05 / THE MODULE

Keep the Module. Change the Cell.

N6-RB uses a replaceable 21700 cell, allowing the battery to be changed separately from the charging module.

When you need more runtime, swap a depleted cell for a charged one. When a cell ages, replace it while keeping a functioning module in use. Carrying suitable, protected spare cells gives you another way to prepare for a longer day.

We see replaceability as a practical step toward keeping useful products in service — spent cells can be handled separately through appropriate battery-recycling channels. Make the part that needs changing accessible, and preserve what still works.

N6-RB color exploration prototypes
06 / THE PERSONALITY

A Little Personality Goes a Long Way.

The things you carry are personal. You choose them for what they do, how they feel, and how naturally they fit into your routine.

N6-RB combines everyday charging with a rotating ring that adds a satisfying tactile interaction — something for your fingers to turn during a pause in the day, and a recognizable silhouette.

Color adds another layer. Black and red create a sharper mechanical look; green and pink bring a more playful character. Across the collection, contrasting colors highlight the same distinctive form in different ways. We want you to find a version that feels like yours.

N6-RB four colorways collection

Four Colors. One Shared Idea.

Starlight Black · Roland Purple · Butterfly Green · Gardenia Yellow
// REPLACEABLE BATTERY AT THE CORE
// Our Next Chapter Is Everyday
Sometimes improvement begins with a more accessible component. Sometimes it is a detail that makes an ordinary interaction more enjoyable.

N6-RB brings these ideas to portable power. Our direction is to keep exploring charging products that offer useful choices, clear ways to care for them, and good reasons to keep using them — for the commute, the workday, and the plans that change along the way.

Explore N6-RB
// Behind the Brand

KangTao Smart

A technology brand operated by KANGTAO SMART ELECTRONICS LIMITED, based in Hong Kong. We focus on modular portable charging products that combine practical functionality with distinctive everyday design.

BRAND — KangTao Smart
COMPANY — KANGTAO SMART ELECTRONICS LIMITED
BASE — Hong Kong
CONTACT — service@kangtaosmart.com