ClearAll[Foldint]
Foldint[f_,z_,0]:=z
Foldint[f_,z_,n_]:=f[n,Foldint[f,z,n-1]]

ClearAll[Charge,Chargebis]
Charge[nb_,maxz_]:=ListAnimate[Foldint[(Join[#2,{ListPlot3D[Import["/tmp/essai"<>ToString[#1]<>".dat"],PlotRange->{0,maxz}]}])&,List[],nb]]
Chargebis[nb_,maxz_]:=Foldint[(Join[#2,{ListPlot3D[Import["/tmp/essai"<>ToString[#1]<>".dat"],PlotRange->{0,maxz}]}])&,List[],nb]

Chargebis[20,100]

Charge[20,100]