Let’s be real for a second: how many times have you looked at your phone and seen that dreaded red battery icon just when you needed it most? Maybe you’re at the airport trying to show your boarding pass, or lost in a new city relying on Google Maps, or about to pay for coffee with Apple Pay—only to realize your phone is about to die. TAU 2 keychain power bank

Enter the Rolling Square TAU 2, a ridiculously compact keychain power bank that just might be the hero you didn’t know you needed. It’s not trying to replace your big 20,000mAh power brick. It’s not here for your weekend camping trip. This is a pocket-sized emergency life-saver, designed for everyday minimalists and frequent travelers who just need that little bit more to make it through the day.

Let’s dive in.

Tiny but Mighty

At first glance, the TAU 2 doesn’t even look like a power bank. It’s smaller than a car key fob—seriously. It’s so tiny that you might even forget it’s on your keychain… until you really need it.

We’re talking about 2000mAh of backup juice. That’s not enough to fully charge your phone, but that’s also not the point. It’ll get you from 2% to around 50% on most phones—just enough to call your Uber, find your hotel, or reply to that important message.

All the Cables You Need. Literally.

This is where the TAU 2 flexes. Built into its body are three connectors:

• Lightning for iPhones
• USB-C for basically everything else (Android phones, earbuds, newer tablets)
• Micro-USB for those random older devices (looking at you, wireless speakers and fitness trackers)

No tangled cables. No adapters to lose. No “oops, I brought the wrong cord” moment. Just grab and go. It’s built for real-world travel and those of us who’ve packed too many chargers for one weekend getaway.

Charging the TAU 2: USB-A or Wireless

Here’s something clever—Rolling Square gives you two ways to charge the TAU 2 itself.

Option 1: Plug it into any USB-A port. There’s a built-in USB-A plug that folds out. Stick it into your laptop, car charger, or any basic USB port and it’ll juice up.

Option 2: Drop it on a wireless pad. Yes, the TAU 2 supports wireless charging. That’s pretty wild for something this small. If you’ve got a wireless charger at home, just plop it on and let it do its thing. No cables needed, ever.

(Just to be clear—it can’t charge other devices wirelessly. That would be witchcraft.)

Minimalist Traveler’s Dream

If you’re the type who packs light, hates clutter, and wants your tech gear to just work, this is for you.

• It’s always with you (because it’s on your keychain).
• You never have to think about what cable to bring.
• You don’t even need to remember to pack a charger.
• It’s airline-safe and small enough to breeze through security.

Whether you’re exploring a city, hiking a trail, or just commuting to work, it’s the kind of tool that fades into the background—until it becomes essential.

The Build: Clean, Durable, and Thoughtful

Rolling Square is known for well-designed gear (you may know them from the inCharge cable series), and the TAU 2 keeps that streak alive.

The outer shell feels solid and matte—no cheap plastics here. It’s water-resistant, scratch-resistant, and made to survive the chaos of travel. The connector arms fold in securely and don’t dangle or snag.

There’s also a handy little LED indicator that shows you how much charge is left. One light = low, four lights = full. Simple.

And yes, it does come with a keyring holder that also acts as a magnetic charging dock. Mount it on your wall, near your desk, or wherever you’ll remember to dock it at night. It looks sleek, and honestly, feels like something Apple would design (but without the Apple price tag).

Real-Life Scenarios

Let’s talk about some actual moments when the TAU 2 shines.

• You’re at a music festival. Your phone’s at 12% by 9 PM. You want to take videos, order food, and make sure you can get home. TAU 2 gives you that buffer.
• You’re on a city break in Europe. No space for bulky gadgets. You walk 20,000 steps a day and use your phone constantly for translations, maps, and photos. TAU 2 = peace of mind.
• You’re on a long train ride. You forgot your big power bank, but your keychain is always with you. Plug in, scroll away, and recharge just enough to last until you reach your destination.

Things to Know

Let’s be honest—this isn’t a miracle device. A few caveats:

• It won’t fast-charge. It’s meant for emergency top-ups, not speed.
• It’s not high-capacity. Don’t expect multiple full phone charges.
• Wireless charging of the device is slower than USB-A. Makes sense.

But again, that’s not its mission. It’s not trying to compete with your Anker 20k mAh block. It’s meant to be with you always and bail you out when you’re in trouble.

The Verdict

The Rolling Square TAU 2 isn’t trying to be your main power source. It’s the backup to your backup. The last-minute hero. The digital equivalent of carrying a €20 bill in your wallet “just in case.”

It’s smart, pocketable, practical, and well-designed. And for travelers who like to stay light and agile, it’s kind of perfect.

We all love shiny, overpowered tech. But sometimes, the best gear is the one that doesn’t get in the way. That’s exactly what the TAU 2 does: it stays out of sight until you need it most.

Final Thought

If you’ve ever lost phone power at the worst possible time—and we all have—this €30-ish investment could make a real difference. And considering how often we carry things we might need, the TAU 2 is something you’ll be glad you do.

Quick Specs Recap:

• Capacity: 2000mAh
• Connectors: Lightning, USB-C, Micro-USB
• Charging: Built-in USB-A + Wireless charging
• Size: Smaller than a car key
• Extra: Magnetic dock/keychain holder

Would I recommend it? Absolutely—especially if you’re the kind of traveler who packs smart, travels light, and hates low battery anxiety. The TAU 2 punches well above its weight.