This battery solution is a “do-it-yourself” project which you attempt under your own risk.
That’s wy the description is not in great detail.
Someone with enuf technical knowledge will know how to use these items en will know how to build this in a battery for the Fujica GX680.
I’ts a real easy project.
Note: use a battery holder for 6 AA (penlite) battery’s
Only use 1,2 volt rechargeable battery’s (NiMh or NiCad) (these are the standard rechargeable penlites)