Vbat on SIM800H Shield For Arduino

I have a SIM800H GPRS IOT Shield For Arduino, and want to use a battery on the shield+arduino assembly. I've seen on sim800h there is a Vbat pin, and the command at+cbc to know the battery power level, and if it's recharging or not. With this shield and arduino, is it possible to use this pin and how to connect the battery ? If yes, how can I use the command at+cbc ?

Thanks to anybody interesting by my post and the answers and advises they can give me.

(ps: Sorry for my bad english)