* Keep your devices powered at home, at work and on the go
* These portable power banks are small enough to fit in most pockets and wallets
* Choose from basic designs, multiple USB options and more
You use your phone at work, at home and even in the car. For most of us, our smartphones are an extension of ourselves. If you’re worried about getting stuck without power, here are four mini battery packs that are small enough to slip in your wallet, but big enough to offer power where it counts.
1. Ultra Slim Wallet Pocket Power Card Power Bank
At barely 6mm thick, this tiny power bank features a sleek, on-the-go design. Built-in smart control technology helps prevent excess overheating, helping this power bank stay strong no matter where you are.

2. Ainope 10000mAh Portable External Battery
Backed with 1000omAh of pure, portable battery power, this tiny pack features its own LCD display and dual USB outlets for simultaneous chargers. It can even power the average iPhone roughly 3.6 times over on a single charge.

3. WEme Aluminum 4 Port USB 3.0 Hub
With three built-in USB ports, this portable power hub is able to charge multiple devices at once — making it easier for you to give all your devices a little juice before you leave the house (or office).

4. oisle Portable Charger Mini Power Bank
A smarter way to charge your phone, this original power bank sports 2200mAh of charging power and actually clips onto the back of your phone. At less than .29 inches thick, you’ll barely even notice it’s there.

This $40 Robot Charger Talks To You Every Time You Plug In Your Device