Forgetful? This tiny key chain energy financial institution may also help you out of some jams


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What’s Tau?

Made by Rolling Sq. — the corporate behind the actually cool inCharge X, 6-in-1 charging cable — Tau is designed to maintain your smartphone charged up and your keys in a single place. 

Tau is a tiny energy financial institution key fob that magnetically attaches to a wall-mounted charger. Within the morning, you seize your keys together with a fully-charged energy financial institution. Once you come again within the night, you pop your keys again within the holder and cost up the ability financial institution.

This fashion, the place your keys are, and also you all the time have a charged-up energy financial institution.

Additionally: The 5 greatest transportable energy banks

Oh, and the ability financial institution incorporates a built-in USB-C, a Lightning cable, and a microUSB cable, so you do not even have to recollect to carry separate cables. 

Rolling Sq. Tau tech specs


  • Lightning (iPhone, iPad, iPod, AirPods)
  • USB-C gadgets
  • microUSB gadgets


  • Dimension: 60 x 45 x 12 mm / 2.32 x 1.77 x 0.47 in
  • Weight: 40 g / 1.4 oz
  • Capability: 1400 mAh
  • Weight: 350 g / 12 oz

Within the field

  • Tau energy financial institution
  • Tau Dock and USB energy cable
  • Screws and wall plugs
  • Nano suction double-sided layer
  • Consumer guide
  • Eco-friendly packaging

Additionally: This tiny USB-C charger packs a whole lot of energy

Tau package on a brown background.

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In keeping with Rolling Sq., Tau is the smallest energy financial institution on this planet. I am unable to affirm this, nevertheless it actually is small and lightweight, and it is no larger than a automobile key fob. 

The 1400mAh battery is not going to be sufficient to completely cost a contemporary smartphone, and the 1A charging energy is not going to be quick, however it would get you out of a low battery jam, for positive.

Model, input, output, and capacity info for Tau

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On the underside of the important thing fob is a magnetic charging port that hooks in with the dock. The dock itself may be hooked up to a wall utilizing the offered screws of a nano suction pad.

Closeup of Tau's magnetic charging port

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On the opposite finish are the 2 charging cables, one for USB-C, the opposite for Lightning and microUSB.

Closeup of Tau's charging cables

Adrian Kingsley-Hughes/ZDNET

Additionally: Faux Lightning cables can injury your iPhone. This is how to ensure yours is real

This is the fob within the charging dock, with the dock charging cable hooked up. It is a neat bundle.

Tau against a brown background in dock with keys attached

Tau in dock with keys hooked up… prepared for motion.

Adrian Kingsley-Hughes/ZDNET

Tau is all the things I anticipate from Rolling Sq. — a top quality product that truly solves an actual drawback. A tiny energy financial institution disguised as a key fob and a well-mounted charging dock turns this from what may be thought-about a gimmick into a useful gizmo. 

That is excellent for individuals who neglect the place they’ve put their keys and run out of the home within the morning with a smartphone that is nearly useless.

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