Puli (GL-XE300) battery and antenna questions

A few questions regarding the GL-XE300

Battery life, for how long does the battery last when in use ?
Can the device be used while charging, my thought is if I must to charge the device with a power bank to get a few more hours of up time, and the connection of a external power source does not restart it.
External antennas, is there both for 3/4G and Wifi or only one of them?

Maybe 8 hours.

It can be used while charging.

External antenna maybe only for LTE.