TAU 2 Keyring Power Bank vs Regular Power Bank: Size vs Capacity
By Rolling Square | The lifehackers company | Published: 2026-10-18
Category: Comparisons
Compare the TAU 2 emergency keyring power bank with a standard power bank. See the trade-offs between pocket-friendly design and full-day charging capacity.
Quick answer
If you want a backup battery that lives on your keys and never gets left behind, the TAU 2 emergency keyring power bank is the clear choice. If you need enough capacity to charge a phone multiple times or power a laptop, a regular power bank is still necessary. The trade-off is always-ready convenience versus all-day capacity.
What each device is designed for
The TAU 2 is a 3-in-1 emergency keyring power bank built to be always charged and always on your keys. Its job is to give your phone a quick boost when the battery hits single digits — not to replace a full-size power bank for a day of heavy use.
A regular power bank, like the Essential GaN Charger 100W, is meant to charge phones, tablets, and even laptops from near-empty to full, often more than once. It sits in a bag or desk drawer and delivers higher wattage and much larger capacity.
Size and portability trade-off
The TAU 2 is small enough to hang on a keyring without adding noticeable bulk. You never have to remember to grab it — it is already there. The trade-off is a smaller battery cell that provides one partial charge for most phones.
A regular power bank, especially a 100W GaN model, is physically larger and heavier. You will feel it in a pocket. But that size difference pays off in capacity: you can charge a phone two or three times or top up a laptop during a workday.
Key trade-offs between TAU 2 and a regular power bank
- Always-ready vs planned charging: The TAU 2 lives on your keyring, so it is always with you. A regular power bank must be remembered and packed. If you often forget your power bank, the TAU 2 removes that friction.
- Capacity: emergency top-up vs full recharge: TAU 2 provides one partial phone charge. A regular 100W power bank can fully charge a phone multiple times and power a laptop. For a full day away from outlets, a regular power bank is still needed.
- Size and carry method: TAU 2 clips to keys and fits in a coin pocket. A regular power bank requires bag or jacket space. The smaller size of TAU 2 means you trade capacity for ultra-portability.
Product facts at a glance
- TAU® 2 - Emergency keyring power bank: TAU® 2 is a 3in1 emergency keyring power bank that stays on your keys and is always charged for urgent phone calls, payments, or GPS. You never have to plan ahead — the battery is already in your pocket or bag, ready for a quick emergency boost.
- Essential GaN Charger - 100W power, 45% smaller: Essential GaN Charger 100W is 45% smaller than traditional chargers but still delivers 100W of power through dual USB-C PD 3.0 ports, plus extra USB-C and USB-A ports. This represents the opposite end of the trade-off: high capacity and multi-device charging in a still-compact travel charger, but not something you clip to your keys.
Which one fits your routine?
Best for
- People who want a backup battery they never have to remember to bring
- Daily commuters who only need a quick emergency charge for calls or maps
Not for
- Travelers who need to charge a phone multiple times or power a laptop during a full day out
- Users who prefer a single device for both emergency and heavy charging needs
