If you use a Fatshark avaiator edition and you fly with the integrated receiver module, you can use the standard Fatshark LiPo without a problem, because a red light in the fatshark will warn you a few minutes before the battery is empty (battery life time ~1hour when using the integrated receiver, ~2,5hours).
But you will not be warned when you use an external receiver and because the Fatshark LiPo got no balancer connector, you can’t use your LiPo checker to make sure the LiPo got enough power for the next flight.
That’s why we recommend to buy a 2s 800mah LiPo and create two cable adapters (one for the FatShark connection and one for charging).
Of course you don’t need the charging adapter if you have the opportunity to charge your LiPo just by using the balancer connector.
Here is my soloution:
It is also possible to connect the FatShark to a LiPo that is at your groundstation if you prefer that.