Anker® SLIM2 Astro 4500mAh External Battery Portable Ultra Fine with a Micro-USB cable for Samsung Galaxy S5 Concealable, Galaxy S4, Galaxy S3; Apple iPhone 5s 5c 5 (lightning arrester connector not included); Wiko Cink Peax 2; Sony Xperia Series (Electronics)
A very nice addition to battery, the integrated cable allows not end up like an idiot when you have the battery but not the cable. It recharges fully once my Galaxy Note 2 (which remains in use during charging) It is relatively big but (size of a small smartphone) but it is fairly flat so it slips easily into the pocket with the smartphone, or in the hand during use.