General wifi can be used for about 5-6 hours, and some can be used for more than 10 hours, relatively large such as roaming Superman can be standby for 15 hours, and the device itself can be used as a charging treasure, generally do not need to charge down the day, the last time I went to rent a shop in Europe, their home has roaming treasure, roaming Superman and Global roaming. They generally give the roaming treasure and the global roaming such a short standby time with a small charging treasure, you can charge anytime and anywhere, so that after the day basically do not need to charge.