You can use an ultra compact power bank for extra talk time, but if you need more battery life for your iPhone 5, the Oivo ultra portable iPhone charger may be a nice solution.
The Oivo is a practical and portable charger designed for iPhone 5/5s/5c. The iPhone charger measures 1.18 x 1.43 x 0.86 inches and as shown in the images, it sports an ultra compact design, using an integrated key ring, you can easily attach it onto your keychain for easy to carry. The Oivo portable charger doesn’t have built-in backup battery, so you need to mount four AA batteries or rechargeable batteries on the charger in order to charge your iPhone 5. When not in use, its two pieces can be put together using built-in magnets. Apart from that, the portable charger doubles as an iPhone stand that support both portrait and landscape viewing modes.
The team of the Oivo is raising fund via Kickstarter. Pledging $39 will let you own the iPhone charger. If you’re interested, jump to Kickstarter official site for more details or check out the following demo video.