Battery attachment with water bottle bolt came loose

[ROJA]

This is at least those with 2013-2016/7 Turbos with the battery integrated into the downtube and water bottle cage bolts that screw into round screw-looking things that actually screw into the battery. Perhaps it's also the same on later models.

The screw / circular bolt that goes into the battery has come loose and you can literally see inside my battery. Does anyone know how to fix/tighten this? Thanks!

 

[ROJA]

For reference, the whole black cap is threaded and screws in and out. I did it by hand to get to the shop but something like channel locks or pliers would probably get it plenty tight.