Not long ago I purchased the Fatshark Dominator V2 FPV Goggle. Everything works great except the battery plug and connector is a bit cumbersome. This supplied LiPo battery is a 7.4V 2S 1000mah, it has a cylinder connector and not the ordinary JST connector. That means when you are charging, you need a discharge plug adapter, when you want to use a different 2S battery for your FPV goggle, you will also need an adapter. (unless you are using the genuine Fatshark battery)
So that is simple, get rid of the cylinder connectors on the battery and replace it with a JST connector, so it can be charged directly without using an adapter. This mod should work for Skyzone FPV goggle as well I think. (Further Reading: FPV Goggles Comparison Chart)
Remove the original connector from the battery, and solder a male JST connector to it. Take the cylinder connector you just removed from the battery, and solder a female connector to it.
Now you can also use a spare normal 2S lipo battery for this FPV goggle too! I am using a 2S 1300mah Lipo, it can run 3 and a half hours on this FPV goggle, just amazing!
And charging becomes so much easier for the Fatshark battery, and we can forget about the lipo adapter.