Whether you are on vacation, traveling or having a night out with friends, don't be stressed out about seeing the last 10 percent of the battery of your portable devices thanks to the external battery. And in this sense, it is important to select the best external battery according to its capacity therefore depends in particular on the duration of the planned trips. For example with a capacity of 5000 mAh maximum, you can use it as a backup battery, easily transportable in a bag. For longer trips: between 5,000 and 10,000 mAh will suffice and for an external travel battery, aim instead between 10,000 to 20,000 mAh. If you plan to travel around the world, you may need 20,000mAh or more. Nomadic by nature, the ideal external battery is small and light. But this criterion does not have the same importance for all users: fundamental if you plan to carry your accessory daily in your pocket, it weighs less if the back-up battery is intended to remain in the car. On average, the weight of external batteries varies between 80 and 500 grams.