Gl-mifi + ar150

I apologize in advance if my questions seem stupid, I’m new)
So, I need an encrypted Wi-Fi channel in the VPN network (either, speed is not particularly important). I have a GL-MIFI in conjunction with the AR150.
MIFI purchased in the official store, but for some reason they could not send me with the battery ((I picked up my version for 7500Mah (at 12000Mah did not climb)) and I inserted it into an extra battery.
Question one: on the MIFI board there are 2 power connectors. Bat + / GNT and 5V / GNT … From the Bat MIFI connector it does not start. From 5V there is a start. The second battery is connected to the Bat socket which function does it perform? Charges the battery in the 5V connector or vice versa?
The second question: Wi-Fi will always distribute from the SIM tray, tell me how to better configure and what firmware to use?

Thanks in advance)

If you got a MiFi non battery verstion, it means you cannot connect a battery to it.
If you got a MiFi battery version but the battery is not attached, then it is possible to attach a battery.

So, maybe your MiFi cannot connect battery at all.

Please note a battery is 3.7V Lipol. If you use power banks, it is 5V so it is not a merely a battery. It has its own circuit.

About your second question, I cannot understand. Can you describe in another way?