Here it says that Zerubavel was Ben Pedayah. It says in Chagai, Zecharyah and Malachi that he was Ben She'alti'el!
Radak: He was She'alti'el's grandson; often, grandsons are called sons.
Malbim citing Ibn Ezra: Pedayah was She'alti'el's brother. She'alti'el died without children, and Pedayah did Yibum with the widow, so Zerubavel is called Ben She'alti'el based on the deceased, even though his father was Pedayah.
Did Zerubavel have only one son?
Radak: It means u'Vnei Zerubavel. The same applies to "u'Ven Chananyah" and "u'Ven Ne'aryah" (21, 23).
What is the significance of the name Zerubavel?
Sanhedrin 37b: He was Nizra (conceived) in Bavel. His true name was Nechemyah ben Chachalyah 1 .
Ramah (37b): He was the son of Yechanyah! Also, verses list Zerubavel separately from Nechemyah! Margoliyas ha'Yam - 'Ben Chachalyah' means 'the son of one who was Chayav Kelayah (worthy to be destroyed).' A different Nechemyah was listed with Zerubavel.
