Havdalah for Bar Mitzvah on Motza'ei Shabbat

Question: Can someone who becomes Bar Mitzvah on Motza'ei Shabbat recite Havdalah for himself and for others?
Answer: A Bar Mitzvah is obligated in the mitzvot, but he was not obligated on Shabbat. He should therefore hear Havdalah from someone else and all the more so not fulfill the mitzvah for others (Shut Har Tzvi #165 and Ha-Rav Shlomo Zalman Auerbach in Halichot Shlomo - Tefillin chap. 2 note #48).