From the sounds of it your system got quite wet, it’s likely the logic board sustained damage.
I would start off carefully inspecting the logic board for damages components as well as corrosion damage on both side of the logic board, I would also look at the inside surfaces for staining as that can point to where the spill effected.
I would hold off replacing the battery until the damage is repaired as that could lead to more serious damage.
It might be wise to seek out a Mac repair expert as this will likely require logic board component replacement.