Portable chargers.

Portable chargers

Price: about 100 yuan

Once upon a time, the popular game to play in order to kill time during a long journey was poker. Now, with smartphones and tablets becoming popular, it is necessary to take external batteries to sustain these energy-consuming devices. Portable batteries with a capacity of less than 100 watt-hours are allowed in carry-on luggage on aircraft. Each passenger is allowed to carry no more than two portable batteries with a capacity between 100 to 160 watt-hours, and those above 160 watt-hours are prohibited on aircraft.