Next year he was Jacques Maurice Hatry's chief of staff during the Siege of Luxembourg.

In 1806 Charpentier became chief of staff to Eugène de Beauharnais in Italy but later fought at Burgos in Spain in 1808.

Serving under Eugène again, in 1809 he was present at Sacile, Caldiero, the Piave, Tarvis, Raab and Wagram.

In 1813 he led an infantry division in the XI Corps at Lützen, Bautzen, Katzbach, Leipzig, Hanau and Arnhem.

In 1814 he led a Young Guard division at Craonne, Laon, Fère-Champenoise and Paris.