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TAU® 2 - Emergency keyring power bank
Color: Ice Gray
Ice Gray
Mercury Black
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TAU® 2 is the emergency power bank for every device (Lightning, Micro USB, USB-C). Its keyring form factor is perfect to let you attach it to your keys when carrying it around.
TAU® 2 is the emergency power bank for every device (Lightning, Micro USB, USB-C). Its keyring fo...

TAU® 2 | 3in1 emergency keyring power bank
Introducing TAU 2 - your trusty, always-charged, universal keyring emergency power bank. Never again will you have to suffer the indignity of your phone giving up on you at the worst possible moment. You’ll no longer need to carry bulky power banks to make important calls 📞, pay with your phone 💳, or use GPS maps 🗺️, even towards the end of the day when your phone's battery is running low. 

You'll never forget to re-charge it
With TAU 2, forgetting to charge your power bank is a problem of the past. Charge your TAU 2 just by putting away your keys the way your mother told you. We even took the time to give you a quick and easy way to set up its charging dock on a desk, on a wall, or even the door side table. Now your power bank is always fully charged and within reach right alongside your keys, eliminating the frustration of a dead battery when you're on the go. Your keys are always in the right place and your power bank is always charged. 🔑🔋

Your keys' new best friend
TAU 2 is so small and compact that it easily fits on your keyring without adding any bulk. The fact that it hooks on your keys means that so long as you have your keys you also have power. The fact that it's always charged means that the Charging Dock will serve as your new tidy place for keys, seamlessly recharging TAU 2 without you even noticing, so it's ready for your next departure. Say goodbye to carrying around a separate power bank with cables in your bag or pocket, or worse, forgetting to bring them with you!

Battery capacity
TAU 2 may not immediately captivate with its 2000mAh capacity, but it's truly impressive. 🔍 We tested smartphones from major processor producers, revealing three battery improvement ranges: small-battery phones gained up to 54%, mid-battery phones up to 35%, and large-battery phones up to 28%. We calculated these results conservatively, considering battery consumption data from producers, reviewers, and real-life tests, factoring in dispersion and performance decrements due to background apps. Visit the "battery capacity" section on our Kickstarter's TAU 2 page for a detailed understanding of our tests and results!

Key features (3in1)

  • Charge USB-C devices
  • Charge Lightning devices
  • Charge Micro USB devices

    Extra features

    • Included NFC tag for Digital ID and Lost mode
    • Optional adhesive QR Code stickers for Digital ID and Lost mode
    • Pass-through charging (USB-C as input, Lightning/Micro USB as output)
    • Quick-release keyring hook

    Designed with love
    ❤️️ in Switzerland



      Lightning (iPhone, iPad, AirPods)
      USB-C devices
      Micro USB devices


      Size: 56*x43x19mm (2.2*x1.7x0.7in) *Dimension without hook. Dimension with hook: 63mm / 2.5in
      Weight: 50g / 1.7oz
      Capacity 2000 mAh
      Holdable weight: 690gr / 24oz


      TAU® 2 Power bank

      TAU® 2 Dock with USB-C integrated cable
      Nano suction double-sided layer
      User manual
      Eco-friendly packaging

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      Customer Reviews

      Based on 14 reviews
      shipping and communication were…

      shipping and communication were efficient. the product is sturdy. I tried to adjust my reusable base adhesive, only a few days after hanging it near my keys, and it came apart- easy enough to put back together, but maybe it's too sticky for a wooden cupboard.

      Easy Quick and Ready to Use

      Love how easy it is to carry around and charge it at night. It helps extend my phone battery life and is easy to keep up with. I would definitely recommend it to others!

      Ryan Belchamber
      Great quality

      Had a few things from rolling square now and all have been of exceptional quality and they last. Would defo buy again 👍👍👍

      Ále Gonzalez
      Extremely satisfied!

      The product was all that I expected and more. Extremely satisfied!